FR3071876B1 - VENTILATION DEVICE FOR A HEAT EXCHANGE MODULE OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a ventilation device (2) for generating an air flow in the direction of a heat exchanger (1) of a motor vehicle, the ventilation device comprising ducts (8) intended to be supplied with flow. of air by at least one air propulsion device, each duct (8) having at least one opening (16; 40) for ejecting a flow of air passing through said duct (8), substantially in the direction of said heat exchanger (1), the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said air propulsion device.

Description

VENTILATION DEVICE FOR AUTOMOTIVE VEHICLE HEAT EXCHANGE MODULE

The present invention relates to a ventilation device for a heat exchange module and a heat exchange module for a motor vehicle.

A heat exchanger generally comprises tubes, in which a coolant is intended to circulate, and heat exchange elements connected to these tubes, often referred to as "fins" or "spacers".

The fins increase the exchange surface between the tubes and the ambient air. However, in order to increase the heat exchange between the coolant and the ambient air, it is common that a ventilation device is used in addition to generate a flow of air directed to the tubes and fins.

Such a ventilation device most often comprises a propeller fan, which has many disadvantages.

First, the assembly formed by the propeller fan and its motorization system occupies a large volume.

In addition, the distribution of the air vented by the propeller, often placed in the center of the row of heat pipes, is not homogeneous over the entire surface of the heat exchanger. In particular, certain regions of the heat exchanger, such as the ends of the heat pipes and the corners of the heat exchanger, are not or only slightly reached by the air flow ventilated by the propeller.

Finally, when the start of the ventilation device is not necessary, especially when the ambient air flow created by the movement of the motor vehicle is sufficient to cool the coolant, the blades of the propeller partially mask the air. 'heat exchanger. Thus, a portion of the heat exchanger is not or only slightly ventilated by the ambient air flow in this case, which limits the heat exchange between the heat exchanger and the ambient air flow.

Furthermore, it is known from German patent DE 10 2011 120 865 a motor vehicle having a ventilation device and a heat exchanger, the ventilation device being adapted to generate a flow of air through the heat exchanger. The ventilation device is adapted to create a secondary air flow from a primary flow emitted from one or more annular elements, the secondary air flow being much stronger than the primary air flow. According to this patent, the ventilation device is part of a cooling grid disposed on the front face of the motor vehicle.

In such a motor vehicle, each annular element is supplied with primary air flow by a single fan, disposed outside the annular element, via a duct opening punctually in the annular element. Consequently, the ejected air flow emitted by the annular element is not homogeneous on the contour of the annular element. On the contrary, the air flow emitted is all the more important as it is close to the fan. It follows the creation of a secondary air flow through the heat exchanger which is also inhomogeneous.

Finally, it is known from the application DE 10 2015 205 415 a ventilation device intended to generate an air flow through a heat exchanger comprising a hollow frame and at least one hollow spacer, dividing the surface delimited by the frame. cells. The frame and the spacer (s) are in fluid communication with a feed turbine engine in a flow of air. The turbomachine is disposed outside the frame. The frame and possibly the spacer or spacers are further provided with an ejection opening of the flow of air flowing through them. Again, the ventilation device does not generate a homogeneous air flow through the heat exchanger. On the contrary, the air flow emitted by the device is all the more important that it is ejected from the ventilation device near the turbomachine. The invention aims to provide an improved ventilation device does not have at least some of the aforementioned disadvantages. For this purpose, the invention proposes ventilation device for generating an air flow towards a motor vehicle heat exchanger, the ventilation device comprising ducts intended to be supplied with air flow by at least an air propulsion device, each duct having at least one ejection opening of an air flow passing through said duct, substantially towards said heat exchanger, the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least some ejection openings and said air propulsion device.

Thus, advantageously, the ventilation device can allow, in one configuration, to blow air through only certain ejection orifices.

Preferably, the ventilation device comprises one or more of the following characteristics, taken alone or in combination: at least one air intake manifold, each duct opening at one of its ends into a separate orifice of the at least one air intake manifold. air intake, the ducts being intended to be supplied with a flow of air by said at least one air propulsion device, via the at least one air intake manifold, said at least one opening of air ejection ducts being distinct from the ends of the corresponding duct, said at least one opening being located outside the at least one air intake manifold, the means adapted to selectively interrupt a fluid communication between at least some ejection openings and said at least one propulsion device comprise means for closing: o at least some orifices of the air collector; and / or o a section of the at least one air collector; and / or o at least some ejection openings, - the means adapted to selectively interrupt a fluid communication between at least some ejection openings and said air propulsion device are passive, the means adapted to selectively interrupt a communication of fluid between at least some ejection openings and said propulsion device being preferably controlled by an air flow rate and / or an air pressure, - the at least one air intake manifold is substantially shaped tubular, preferably cylindrical, and wherein the means adapted to selectively interrupt a fluid communication between at least some ejection openings and said at least one air propulsion device comprise a shutter, the shutter having a substantially complementary section to the cross section of said at least one air intake manifold, the shutter being movable from in said at least one air collector, the shutter is mounted movably against the action of a return spring, the return spring preferably having a stiffness greater than or equal to 5 N / m and / or less than or equal to at 50 N / m, the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device comprise at least one valve, preferably a flip flap, adapted to close at at least one orifice of the at least one air collector, the flip flap being preferably pivotally mounted against the action of a return spring, the means adapted to selectively interrupt a fluid communication between at least some openings of ejection and said air propulsion device are active, - the means adapted to selectively interrupt a fluid communication between at least some ejection openings and said device Air propulsion units comprise at least one of a solenoid valve and a pneumatic valve, at least some ducts are pivotable, preferably around a respective longitudinal axis, the ducts preferably further having an oblong section such that conduits allow the passage of air between the ducts in a first position and that the ducts limit or even prevent the passage of air between the ducts in a second position reached by pivoting the ducts from the first position, - the ducts are substantially rectilinear tubes, aligned to form a row of tubes; the opening is a slot in an outer wall of the duct, the slot extending in a direction of elongation of the duct, preferably on at least 90% of the duct length and / or the height of said at least one opening is greater than or equal to 0.5 mm, preferably greater than or equal to 0.7 mm, and / or less than or equal to 2 mm, preferably less than or equal to 1.5 mm; each duct has, on at least one section, a geometric section comprising: a leading edge; o a trailing edge opposite the leading edge; a first and a second profile, each extending between the leading edge and the trailing edge, said at least one opening of the conduit being on the first profile, said at least one opening being configured so that the flow of air ejected flows along at least a portion of the first profile, - said at least one opening of the first profile being delimited by an outer lip and an inner lip, an end of the inner lip is extended, in the direction of second profile, beyond a plane normal to the free end of the outer lip, the passage section then being defined as the portion of the section of the tube disposed between said end of the inner lip and the trailing edge, on the one hand, and between the first and second profiles, on the other hand; the maximum distance between the first and the second profiles, in a direction of alignment of the ducts, is downstream of the said at least one opening, in the direction of flow of the said flow of air ejected by the said at least one opening, the maximum distance preferably being greater than or equal to 5 mm, preferably greater than or equal to 10 mm, and / or less than or equal to 20 mm, preferably less than or equal to 15 mm, the maximum distance being even more preferably equal to 11.5 mm; the first profile comprises a curved portion whose apex defines the point of the first profile corresponding to the maximum distance, the curved portion being disposed downstream of the opening in the direction of flow of said air flow ejected by said at least one an opening ; the first profile comprises a first substantially rectilinear portion, preferably downstream of the curved portion in the direction of flow of said air flow ejected by the at least one opening, in which the second profile comprises a substantially rectilinear part, extending preferably over a majority of the length of the second profile, the first rectilinear portion of the first profile and the rectilinear portion of the second profile forming a non-flat angle, the angle preferably being greater than or equal to 5 °, and / or less than or equal to 20 °, more preferably substantially equal to 10 °; the first rectilinear part extends over a section of the first profile corresponding to a length, measured in a direction perpendicular to the direction of alignment of the ducts and to a longitudinal direction of the ducts, greater than or equal to 30 mm, preferably greater than or equal to 40 mm, and / or less than or equal to 50 mm; the first profile comprises a second rectilinear part, downstream of the first rectilinear part in the direction of flow of the air flow ejected by the at least one opening, the second rectilinear part extending substantially parallel to the straight part of the second profile, the first profile preferably having a third straight portion, downstream of the second straight portion of the first profile, the third straight portion forming a non-flat angle with the rectilinear portion of the second profile, the third straight portion extending substantially to a rounded edge connecting the third straight portion of the first profile and the rectilinear portion of the second profile, the rounded edge defining the trailing edge of the profile of the conduit; the distance between the second rectilinear part of the first profile and the rectilinear part of the second profile is greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm; said geometrical section of the duct has a length, measured in a direction perpendicular to the direction of alignment of the ducts and at a principal direction of extension of the ducts, greater than or equal to 50 mm and / or less than or equal to 70 mm, preferably substantially equal to 60 mm; - The ventilation device comprises at least a first and a second ducts, the first profile of the first duct being vis-à-vis the first profile of the second duct; - The ventilation device further comprises a third conduit, such that the second profile of the second conduit is vis-à-vis the second profile of the third conduit, the distance between the center of the geometric section of the second conduit and the center of the geometrical section of the third duct preferably being smaller than the distance between the center of the geometrical section of the first duct and the center of the geometrical section of the second duct; and each duct is symmetrical with respect to the plane containing the leading edge and the trailing edge, so that each duct has two symmetrical openings, respectively on the first profile and on the second profile.

According to another aspect, the invention relates to a motor vehicle heat exchange module comprising: a heat exchanger, the heat exchanger having a plurality of tubes, said heat-transfer tubes, in which a fluid is intended to circulate; and a ventilation device as described above in all its combinations, adapted to generate a flow of air to the heat-transfer tubes. The invention will be better understood on reading the following description given solely by way of example and with reference to the drawings in which: FIG. 1 is a perspective view of an example of an exchange module heat with a heat exchanger provided with a portion of a ventilation device; - Figure 2 is a schematic sectional view along the plane II-II of an aerodynamic tube of the ventilation device of Figure 1; - Figure 3 shows schematically a partial section of a manifold of the ventilation device of Figure 1; - Figures 4a, 4b, 4C are views similar to the view of Figure 3, corresponding to three different supply pressures of the ventilation device; FIGS. 5a and 5b are views similar to FIG. 3 of a variant of the collector of the ventilation device of FIG. 1, corresponding to two different supply pressures for the air intake manifold; FIGS. 6a and 6b are diagrammatic perspective views of rocker devices that can be implemented to selectively close vents of an air collector of the ventilation device of FIG. 1; - Figures 7 to 10 are views similar to that of Figure 2, a variant of the tubes of the ventilation device of Figure 1; and FIG. 11 schematically illustrates a variant of the heat exchange module of FIG. 1.

In the various figures, the identical or similar elements, having an identical function or the like, bear the same references. The description of their structure and function is therefore not systematically repeated.

FIG. 1 shows an example of a heat exchange module 10 with a heat exchanger 1 intended to equip a motor vehicle, equipped with a ventilation device 2 according to a first exemplary embodiment. The heat exchanger 1 comprises heat-transfer ducts 4 in which a fluid is intended to circulate. The fluid here is water or coolant. Heat transfer ducts 4 are here substantially rectilinear and extend in a longitudinal direction. The heat-transfer ducts thus form heat-transfer tubes 4. The heat-transfer tubes 4 are parallel to each other and aligned so as to form a row. The heat pipes 4 are substantially all of the same length.

The heat-transfer ducts 4 each extend between a fluid intake manifold 5 and a fluid evacuation manifold 6, common to all the heat-transfer ducts 4. Preferably, the orifices of the fluid intake manifold 5, in which open the heat pipes 4 are all included in the same foreground. Likewise, the orifices of the fluid evacuation manifold 6 into which the heat transfer ducts 4 open are all included in one and the same second plane, preferably parallel to said first plane.

More particularly, and conventionally in motor vehicle heat exchangers, each heat transfer tube 4 has a substantially oblong cross section, and is delimited by first and second planar walls which are connected to heat exchange fins. For the sake of clarity, the fins are not shown in FIG.

The heat exchange module 10 is equipped with a ventilation device 2 comprising a plurality of ventilation ducts 8. The ventilation ducts 8, in the same way as the heat-transfer ducts 4, are substantially rectilinear, so as to form ventilation tubes 8. The ventilation tubes 8 are further parallel to each other and aligned so as to form a row of ventilation tubes 8. The ventilation tubes 8 are also of the same length. The length of the ventilation tubes 8 is for example substantially equal to the length of the heat-transfer tubes 4.

The ventilation device 2 is intended to generate a flow of air towards the heat-transfer tubes 4.

The heat-transfer tubes 4 and the ventilation tubes 8 may all be parallel to each other, as illustrated in FIG. 1. Thus, the rows of ventilation tubes 8 and of heat-transfer tubes 4 are themselves parallel. In addition, the ventilation tubes 8 may be arranged so that each of them is opposite a heat-transfer tube 4.

The number of ventilation tubes 8 is adapted to the number of heat-transfer tubes 4. For example, for a conventional heat exchanger 1, the ventilation device 2 may comprise, for example, at least ten ventilation tubes 8, preferably at least 15 tubes. 8, more preferably at least twenty-four ventilation tubes 8 and / or at most fifty ventilation tubes 8, preferably at most thirty-six ventilation tubes 8, more preferably at most thirty ventilation tubes 8. The heat exchanger 1 may for example comprise between sixty and seventy heat-transfer tubes 4.

The tubes and the number of ventilation tubes 8 of the ventilation device 2 may be such that a minimum air passage section between the tubes of the ventilation device, defined in a plane substantially perpendicular to the flow of air through the ventilation device. Heat exchanger 1 is between 25 and 50% of the surface, defined in a plane perpendicular to the flow of air through the heat exchanger, between two extreme heat transfer tubes.

Preferably, the front surface of the ventilation tubes 8, measured in a plane substantially perpendicular to the air flow passing through the heat exchanger 1, is less than 85% of the front surface occupied by the heat-transfer tubes 4.

Moreover, in order to limit the volume occupied by the heat exchange module comprising the heat exchanger 1 and the ventilation device 2, while obtaining heat exchange performance similar to that of a ventilation device with a helix, the row of ventilation tubes 8 can be arranged at a distance less than or equal to 150 mm from the row of heat transfer tubes 4, preferably less than or equal to 100 mm. This distance is preferably greater than or equal to 5 mm, preferably greater than 40 mm. Indeed, a too short distance between the ventilation tubes 8 and the heat-transfer tubes 4 may not allow a homogeneous mixture of air flow ejected from the ventilation tubes 8 with the induced air flow. An inhomogeneous mixture does not allow homogeneous cooling of the heat transfer tubes 4 and induces high pressure losses. Too great a distance may not allow to set up the assembly formed by the ventilation device and the heat exchange device in a motor vehicle without requiring a suitable design of the power unit and / or other motor vehicle bodies present in the vicinity of the heat exchange module.

Similarly, again to limit the volume occupied by the heat exchange module, it can be ensured that the height of the row of ventilation tubes 8 (the term height here referring to the dimension corresponding to the direction in which the ventilation tubes 8 are aligned) is substantially equal to or less than that of the height of the row of heat transfer tubes 4. For example, the height of the row of heat transfer tubes 4 being 431 mm, it can be ensured that the height of the row of ventilation tubes 8 is substantially equal to or less than this value.

The ventilation device 2 further comprises a supply device supplying air to the ventilation tubes 8, not visible in FIG. 1, via an air intake manifold 12, preferably via two intake manifolds. air 12.

The air propulsion means are for example a turbomachine, supplying the two air intake manifolds 12, disposed at each of the ends of the ventilation device 1, via a respective port 13. In the example illustrated in FIG. 1, the ports 13 are at one longitudinal end of the air intake manifolds 12. Alternatively or additionally, the ports 13 are at the other longitudinal end of each intake manifold 12 and / or arranged on the along the length of the air intake manifolds 12. Alternatively, also, a turbomachine can feed a single intake manifold 12 and not two. One or more turbomachines may also be implemented to supply each air intake manifold 12 or all the air intake manifolds 12.

According to another embodiment, also, the turbomachine or turbomachines are received in one or in each air intake manifold 12, in particular in the vicinity of one or each longitudinal end 12a, 12b of the or each collector. air intake.

Here, however, the air propulsion means are remote from the ventilation tubes 8, outside the air intake manifolds 12 through which the air propulsion means feed airflow the ventilation tubes 8. The or each turbomachine forming the air propulsion means may not be directly adjacent to the air intake manifolds 12. On the contrary, it may be advantageous to be able to remotely transport the turbine engine (s). ventilation tubes 8, in particular through the intake manifolds 12 and, optionally, a suitable air flow circuit putting in fluid communication the port (s) 13 of the air collector (s) 12 to one or more turbomachines .

Each air intake manifold 12 may for example be tubular. In the embodiment of Figure 1, the air intake manifolds 12 extend in the same direction, which is here perpendicular to the elongation direction (or longitudinal direction) of the heat transfer tubes 4 and ventilation 8.

As can be seen in FIG. 1, the air intake manifold 12 comprises a plurality of air ejection orifices 14 each made at one end of a respective tubular portion, each ejection port of air 14 being connected to a single ventilation tube 8, and more particularly to the end of the ventilation tube 8.

Advantageously, each air intake manifold 12 is devoid of any other opening than the orifices 14 and the aforementioned port or ports 13. In particular, the collector 12 is preferably devoid of an opening directed towards the heat exchanger 1, which in this case would make it possible to eject a part of the air flow passing through the air collector 12, directly in the direction of the heat exchanger 1, without traversing at least a portion of a ventilation tube 8. Thus, all the air flow created by the turbine engine or turbomachines through the or the air collectors 12, can be divided between substantially all ventilation tubes 8. This also allows a more homogeneous distribution of this air flow.

Each ventilation tube 8 has, according to the example of Figures 1 and 2, a plurality of openings 16 for passage of a flow of air F2 through the tube 8. The openings 16 of the ventilation tubes 8 are located at 12 More precisely, here, the openings 16 are oriented substantially in the direction of the heat exchanger 1, and even more precisely, substantially in the direction of the heat-transfer tubes 4, the slots 16 being for example arranged vis-à-vis the heat pipes 4 or fins housed between the heat pipes.

Each ventilation tube 8 opens into a hole 14 separate from each manifold 12. Thus, each air manifold 12 has as many orifices 14 as it receives ventilation tubes 8, a ventilation tube 8 being received in each the openings 14 of the air collector 12. This allows a more homogeneous distribution of the air flow passing through each air collector 12, in the various ventilation tubes 8.

Moreover, the air collector (s) 12 and the ventilation tubes (8) are here configured so that an air flow passing through the at least one air collector (12) is distributed between the different ventilation tubes (8), flows through them. different ventilation tubes 8 and is ejected through the openings 16. Thus, the openings 16 being disposed opposite the heat exchanger 1, an air flow F2 is ejected through the openings 16, and passes through the heat exchanger. heat 1.

It should be noted, however, that the air flow Fl passing through the heat exchanger 1 may be substantially different from the air flow F2 ejected through the openings. In particular, the air flow Fl can comprise, in addition to the air flow F2, a flow of ambient air created by the movement of the motor vehicle running.

In the first example illustrated in FIGS. 1 and 2, and as can be seen more particularly in FIG. 2, except at their air intake inlet ends, which have a substantially circular cross-section, the ventilation tubes 8 have a substantially oblong cross-section interrupted by the openings 16.

The choice of this form allows an easy manufacture of the ventilation tubes 8 and gives good mechanical strength to the ventilation tubes 8. In particular, such ventilation tubes 8 can be obtained by folding an aluminum foil for example, but also by molding, overmolding, or by printing in three dimensions metal or plastic.

More specifically, in the first example shown in Figures 1 to 2, the cross section of the ventilation tubes 8 has a substantially elliptical shape whose small axis corresponds to the height of the ventilation tubes 8 and the major axis to the width of the tubes of ventilation 8 (the terms height and width to be understood in relation to the orientation of Figure 2). For example, the small axis h of the ellipse is about 11 mm.

To increase the flow of air F2 ejected to the heat exchanger 1 through the openings 16, the openings 16 are constituted by slots in the wall 17 of the ventilation tube 8, these slots 16 extending in the direction This slot shape makes it possible to constitute a large air passage, while maintaining a satisfactory mechanical strength of the ventilation tubes 8. Thus, to obtain the largest air passage possible, the openings 16 extend over a large part of the length of the ventilation tube 8, preferably over a total length corresponding to at least 90% of the length of the ventilation tube 8.

The openings 16 are here delimited by guide lips 18 projecting from the wall 17 of the ventilation tube 8.

Because they protrude from the wall 17 of each ventilation tube 8, the guide lips 18 guide the air ejected through the opening 16 from the inside of the ventilation tube 8 towards the heat exchanger 1.

The guide lips 18 are preferably flat and substantially parallel. For example, they are spaced from each other by a distance of about 5 mm and have a width of between 2 and 5 mm. The guide lips 18 advantageously extend over the entire length of each opening 16.

The guide lips 18 are preferably integral with the ventilation tube 8. The guide lips 18 are for example obtained by folding the wall 17 of the ventilation tube 8.

Moreover, the openings 16 are also delimited, in the direction of the length of the ventilation tubes 8, by reinforcing elements 20 of the ventilation tubes 8. The reinforcing elements 20 make it possible to maintain the width of the openings 16 constant. this is achieved because the reinforcing elements extend between the two guide lips 18 extending on either side of each opening 16. The reinforcing elements 20 preferably extend in a substantially normal plane the direction of elongation of the ventilation tubes 8, in order to maintain the greatest possible, the section of the openings 16 allowing the passage of the air flow F2. The reinforcing elements 20 are advantageously evenly distributed along the length of the ventilation tubes 8. In the example illustrated in FIGS. 1 and 2, each ventilation tube 8 comprises seven reinforcing elements 20. Of course, this number is in no way limiting.

Remarkably, the ventilation device 2 is provided with means 100 adapted to selectively interrupt a fluid communication between at least some ejection openings 16 of the ventilation tubes 8 and the air ejection device (s) supplying the tubes ventilation 8 in airflow. Such means make it possible in particular to eject or not a flow of air through certain ejection openings 16, for example depending on their position. It is thus possible to adapt the flow of air ejected by the ventilation device 2 and, by the same, the flow of air Fl passing through the heat exchanger. For example, again, it is possible to produce an air flow Fl only with regard to certain elements to be cooled. This may be more particularly advantageous when the ventilation device 2 is associated with different heat exchangers and / or different elements to be cooled, arranged in defined zones facing the ventilation device 2. By "defined zones", it is understood here that areas that can advantageously be distinct, without overlap.

FIGS. 3 and 4a to 4c illustrate a first example of means 100 adapted to selectively interrupt a fluid communication between at least some ejection openings 16 of the ventilation tubes 8 and the air ejection device (s) supplying the tubes ventilation 8 in airflow. Here, these means 100 are more particularly adapted to interrupt the fluid communication between the port 13 of the air intake manifold 12 and the orifices 14 of said intake manifold.

To do this, here, a shutter 102 is mounted free in translation in the air intake manifold 12. The shutter 102 advantageously has a shape substantially complementary to the section of the air intake manifold 12. A seal may also be provided at the periphery of the shutter 102. This provides a good airtightness between the shutter 102 and the walls of the air intake manifold 12. The shutter 102 is here mounted resiliently constrained for example by a spring 104, in the direction of the port 13. Thus, in the absence of air flow from the port 13, the shutter 102 is in its lowest position, corresponding to a break in the communication of fluid of all the orifices 14 located above the shutter 102, at the port 13. Alternatively, depending on the length 1 min of the spring 104 to vacuum, that is to say without air flow supplying the collector d 12 air intake, the position l The lower of the shutter 102 in the air intake manifold 12 may correspond to a fluid communication between the port 13 and a minimum of orifices 14, as shown in FIG. 4a, or even to a fluid communication. between any orifice 14 and the port 13.

In operation of the air ejection device (s), and as visible in FIG. 4b, the shutter is essentially subjected to three forces: its weight, which in the case of FIGS. 3, 4a to 4c is directed vertically towards the bottom of the air intake manifold 12, that is to say to the air supply port 13 of the air intake manifold; the pressure exerted by the flow of air on the lower face of the shutter 102 facing the port 13, partially compensated by the pressure exerted by the air at atmospheric pressure on the opposite face of the shutter 102 (a Exhaust 106 is provided in the air intake manifold to prevent the shutter from acting as a piston and compresses the air due to its displacement); - The elastic return force of the spring 104 which tends to return the shutter 102 to its position in Figure 4a. The elastic return force of the shutter 104 tends to increase with the length 1R of the spring 104, up to the length lmax corresponding to the largest number of orifices 14 in fluid communication with the port 13 and, at the same time, at the greatest force of spring return 104.

Thus, by regulating the pressure of the air flow supplying the air intake manifold 12, it is possible to shift the balance of forces applying to the shutter 102. It is then possible to control the position of the shutter 102 in the air intake manifold 12. This position of the shutter 102 thus controls the number of orifices 14 through which the air supplying the air intake manifold 12 is ejected from the collector air intake 12. In other words, it controls the number of ventilation tubes 8 supplied by the air flow.

The return spring 104 has for example a stiffness greater than or equal to 5 N / m and / or less than or equal to 50 N / m to allow a satisfactory control of the position of the shutter 102 as a function of the pressure of the flow of air supplied by the air propulsion device.

It will be noted here that the means 100 adapted to selectively interrupt fluid communication between at least some of the ventilation tubes 8 and the air ejection device are passive. They are controlled directly by the supply air flow itself.

FIGS. 5a, 5b illustrate a variant of the means 100 adapted to selectively interrupt a fluid communication between at least some ventilation tubes 8 and the air propulsion device supplying the air intake manifold 12 in an air flow. . Here these means 100 include a spring 104 tending to push the shutter 102 towards the end 12b of the air intake manifold opposite the end 12a of the air intake manifold 12 provided with the port 13 by which the air intake manifold 12 is supplied with air flow by the air propulsion device. The spring 104 compresses when the pressure inside the air intake manifold increases (see FIG. 5b), when the air propulsion device blows air into the collector 12 via the port 13, then returns to its initial when the pressure decreases inside the intake manifold 12 (see Figure 5a).

According to another variant not shown, the means 100 adapted to selectively interrupt a fluid communication between at least some ventilation tubes 8 and the air propulsion device supplying these tubes in airflow is devoid of elastic return spring. In this case, the position of the shutter is defined by controlling the pressure of the airflow so that it essentially compensates for the weight of the shutter.

Figures 6a, 6b illustrate other means 200 adapted to selectively interrupt a fluid communication between at least some ventilation tubes 8 and the air propulsion device supplying airflow to the ventilation tubes. According to the example illustrated in these figures, these means 200 take the form of a flip-flap. The rocker flap 200 essentially comprises a shutter 202 of the air intake manifold air outlet orifice 14, connected to a control pallet 204 by a lever arm 206 pivotally mounted relative to to an axis of rotation 208. The lever arm 206 may be pivotally mounted against the action of a return spring. Thus, as with the first means 100, it is possible to control the fluid communication of the ventilation tubes 8 with the air propulsion device controlling the ventilation tubes in air flow: by increasing the pressure of the flow of air air supplied by the air propulsion device, it can control the opening or closing of the orifices 14 and, thus, the supply of air flow or not corresponding ventilation tubes 8.

Figures 7 to 10 illustrate variants of the ventilation device 2 and, more specifically, the ventilation tubes 8 of the ventilation device 2.

In what follows, the ventilation tubes 8 are called aerodynamic tubes 8. It may be noted here that the shape of the ventilation tubes 8 is a priori independent of the configuration of the air intake manifolds and / or the shape of the air ducts. means adapted to selectively interrupt fluid communication between at least some ejection openings and said air propulsion device.

According to the example of FIG. 7, an aerodynamic tube 8 has on at least one portion, preferably over substantially its entire length, a cross section as illustrated with a leading edge 37, a trailing edge 38 opposite the leading edge 37 and, here, disposed opposite the heat pipes 4, and a first and a second profiles 42, 44, each extending between the leading edge 37 and the trailing edge 38. The edge of attack 37 is for example defined as the point at the front of the section of the aerodynamic tube 8 where the radius of curvature of the section is minimal. The front of the section of the aerodynamic tube 8 can be defined as the portion of the section of the aerodynamic tube 8 which is opposite - that is to say which is not in front of - of the heat exchanger 1. Similarly, the trailing edge 38 may be defined as the point at the rear of the section of the aerodynamic tube 8 where the radius of curvature of the section is minimal. The rear of the section of the aerodynamic tube 8 can be defined, for example, as the portion of the section of the aerodynamic tube 8 which faces the heat exchanger 1.

The distance c between the leading edge 37 and the trailing edge 38 is for example between 16 mm and 26 mm. This distance is here measured in a direction perpendicular to the alignment direction of the row of aerodynamic tubes 8 and the longitudinal direction of the aerodynamic tubes 8

In the example of Figure 7, the leading edge 37 is free. In this figure also, the leading edge 37 is defined on a parabolic portion of the section of the aerodynamic tube 8.

The aerodynamic tube 8 illustrated in FIG. 7 also comprises at least one opening 40 for ejecting a stream of air passing through the aerodynamic tube 8, outside the aerodynamic tube 8 and the air intake manifold 12, in particular substantially in the direction of the heat exchanger 1. The opening or each opening 40 is for example a slot in an outer wall 41 of the aerodynamic tube 8, the slot or slots extending for example in the direction of extension of the aerodynamic tube 8 in which they are made. The total length of the opening 40 or openings may be greater than 90% of the length of the aerodynamic tube. Each opening 40 is distinct from the ends of the aerodynamic tube 8, through which the aerodynamic tube 8 opens into an air manifold 12. Each opening 40 is also outside the air intake manifold 12. The shape slot makes it possible to constitute a large air passage in the direction of the heat exchanger 1 without greatly reducing the mechanical strength of the aerodynamic tubes 8.

In the following only describes an opening 40 being understood that each opening 40 of the aerodynamic tube 8 may be identical to the opening 40 described. The opening 40 is for example disposed near the leading edge 37. In the example of Figure 7, the opening 40 is on the first profile 42. In this example, the second profile 44 is devoid of opening 40. The opening 40 in the first profile 42 is configured so that the flow of air ejected through the opening 40 flows along at least a portion of the first profile 42.

The aerodynamic tubes 8 of the ventilation device 2 can be oriented alternately with the first profile 42 or the second profile 44 facing upwards. Thus, alternatively, two adjacent aerodynamic tubes 8 are such that their first profiles 42 are vis-à-vis or, conversely, their second profiles 44 are vis-à-vis. The distance between two aerodynamic tubes 8 neighbors whose second profiles 44 are vis-à-vis is less than the distance between two aerodynamic tubes 8 neighbors whose first profiles 42 are vis-à-vis. The pitch between two adjacent aerodynamic tubes or the distance between the center of the geometrical section of a first aerodynamic tube 8 and the center of the geometrical section of a second aerodynamic tube 8, such as the first profile 42 of the first aerodynamic tube 8 either vis-à-vis the first profile 42 of the second aerodynamic tube 8, measured in the direction of alignment of the aerodynamic tubes 8 is greater than or equal to 15 mm, preferably greater than or equal to 20 mm, and / or less or equal to 30 mm, preferably less than or equal to 25 mm.

For each pair of aerodynamic tubes 8 whose openings 40 are in facing relation, the air flows ejected by these openings 40 thus create an air passage in which a part, called induced air, of the ambient air is driven by aspiration.

It should be noted here that the flow of air ejected through the openings 40 runs along at least part of the first profile 42 of the aerodynamic tube 8, for example by Coanda effect. Taking advantage of this phenomenon, it is possible, thanks to the entrainment of the ambient air in the created air passage, to obtain a flow of air sent to the heat pipes identical to that generated by a propeller fan. while consuming less energy.

Indeed, the air flow sent to the row of heat transfer tubes 4 is the sum of the air flow ejected by the slots and induced air. Thus, it is possible to implement a turbomachine of reduced power compared to a conventional propeller fan, generally implemented in the context of such a heat exchange module.

A first profile 42 having a Coanda surface also makes it possible not to have to orient the openings 40 directly towards the heat-transfer tubes 4, and thus to limit the size of the aerodynamic tubes 8. It is thus possible to maintain a passage section. more important between the aerodynamic tubes 8, which promotes the formation of a greater induced air flow. The opening 40 is, in Figure 7, delimited by lips 40a, 40b. The spacing e between the lips 40a, 40b, which defines the height of the opening 40, may be greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, more preferably greater than or equal to 0.7 mm and / or less than 2 mm, preferably less than or equal to 1.5 mm, more preferably less than 0.9 mm, more preferably less than or equal to 0.7 mm. The height of the slot is the size of this slot in the direction perpendicular to its length. The lower the height of the slot 40, the greater the speed of the air flow ejected by this slot. A high speed of ejected airflow results in a high dynamic pressure. This dynamic pressure is then converted into static pressure in the mixing zone of the air flow ejected by the slot 40 and the induced air flow. This static pressure makes it possible to overcome the pressure losses due to the presence of the heat exchanger downstream of the ventilation device, in order to ensure a suitable flow of air through the heat exchanger. These pressure losses due to the heat exchanger vary in particular as a function of the heat pipe pitch and the pitch of the fins of the heat exchanger, as well as the number of heat exchange modules that can be superimposed. in the heat exchanger. However, a slot height too low induces high pressure losses in the ventilation device, which involves using an air propulsion device or several oversized (s). This can lead to additional cost and / or create a space incompatible with the space available in the vicinity of the heat exchange module in the motor vehicle.

The outer lip 40a here consists of the extension of the wall of the aerodynamic tube 8 defining the leading edge 37. The inner lip 40b is constituted by a curved portion 50 of the first profile 42. An end 51 of the inner lip 40b can extend, as shown in Figure 11, in the direction of the second profile 44, beyond a plane L normal to the free end of the outer lip 40a. In other words, the end 51 of the inner lip 40b can extend, towards the leading edge 37, beyond the normal plane L at the free end of the outer lip 40a. The end 51 can then contribute to direct the flow of air flowing in the aerodynamic tube 8 to the opening 40. The opening 40 of the aerodynamic tube 8 can be configured so that a flow of air flowing in this tube aerodynamic 8 is ejected by this opening 40, flowing along the first profile 42 substantially to the trailing edge 38 of the aerodynamic tube 8. The flow of the air flow along the first profile 42 may result from the Coanda effect. It is recalled that the Coanda effect is an aerodynamic phenomenon that results in the fact that a fluid flowing along a surface at a short distance from it tends to outcrop or even hang on it.

To do this, here the maximum distance h between the first 42 and the second 44 profiles, measured according to an alignment direction of the aerodynamic tubes 8, is downstream of the opening 40. The maximum distance h may be greater than 10 mm, preferably greater than 11 mm and / or less than 20 mm, preferably less than 15 mm. Here, by way of example, the maximum distance h is substantially equal to 11.5 mm. A height h too low can cause significant pressure losses in the aerodynamic tube 8 which could require to implement a turbomachine more powerful and therefore more voluminous. For the same value of the distance between the aerodynamic tubes 8, measured according to the direction of alignment of the aerodynamic tubes, a height h too large limits the passage section between the aerodynamic tubes for the induced air flow. The total air flow directed to the heat exchanger is then also reduced.

The first profile 42 here comprises a curved portion 50 whose apex defines the point of the first profile 42 corresponding to the maximum distance h. The curved portion 50 may be disposed downstream of the opening 40 in the direction of ejection of the air flow. In particular, the convex portion 50 may be contiguous with the inner lip 40b delimiting the opening 40.

Downstream of the curved portion 50 in the direction of ejection of said air flow through the opening 40, the first profile 42 of the aerodynamic tube 8 of the example of Figure 7 comprises a first portion 52 substantially straight. The second profile 44 comprises, in the example illustrated in FIG. 7, a substantially rectilinear portion 48, preferably extending over a majority of the length of the second profile 44. In the example of FIG. 7, the length 1 of the first rectilinear part 52, measured in a direction perpendicular to the longitudinal direction of the aerodynamic tube 8 and the alignment direction of the row of aerodynamic tubes, may be greater than or equal to 30 mm, preferably greater than or equal to 40 mm, and / or less than or equal to 50 mm. A relatively large length of this first rectilinear part is desired in particular for guiding the air flow ejected from the opening 40, which makes it possible to ensure greater suction of air. The length of this first rectilinear part is however limited because of the corresponding size of the ventilation device and its consequences on the packaging of the ventilation device or the heat exchange module.

In this case, the first rectilinear portion 52 of the first profile 42 and the straight portion 48 of the second profile 44 may form a non-flat angle Θ. The angle Θ thus formed may in particular be greater than or equal to 5 °, and / or less than or equal to 20 °, more preferably substantially equal to 10 °. This angle of the first rectilinear portion 52 with respect to the rectilinear portion 48 of the second profile 44 makes it possible to accentuate the expansion of the flow of air ejected by the opening 40 and undergoing the Coanda effect forcing it to follow the first profile 42 , this accentuated relaxation to increase the induced air flow. An angle Θ too great, however, may prevent the realization of the Coanda effect, so that the flow of air ejected through the opening 40 may not follow the first profile 42 and, therefore, not to be oriented correctly towards the heat exchanger 2.

The first profile 42 may comprise, as illustrated in FIG. 7, a second rectilinear portion 38a, downstream of the first straight portion 52, in the direction of ejection of the airflow, the second straight portion 38a extending substantially parallel to the rectilinear portion 48 of the second profile 44. The first profile 42 may also include a third straight portion 54, downstream of the second straight portion 38a of the first profile 42. The third straight portion 54 may form a non-flat angle with the rectilinear portion 48 of the second profile 44. The third rectilinear portion 54 may extend, as illustrated, substantially to a rounded edge connecting the third rectilinear portion 54 of the first profile 42 and the straight portion 48 of the second profile 44. The edge rounded can define the trailing edge 38 of the cross section of the aerodynamic tube 8.

The straight portion 48 of the second profile 44 extends in the example of Figure 7 over the majority of the length c of the cross section. This length c is measured in a direction perpendicular to the longitudinal direction of the aerodynamic tubes 8 and to the alignment direction of the row of aerodynamic tubes 8. This direction corresponds, in the example of FIG. 11, substantially to the direction of the flow of the induced air flow. In this first exemplary embodiment, the length c of the cross section (or width of the aerodynamic tube 8) may be greater than or equal to 50 mm and / or less than or equal to 70 mm, preferably substantially equal to 60 mm. Indeed, the inventors have found that a relatively large length of the cross section of the aerodynamic tube makes it possible to more effectively guide the flow of air ejected through the opening 40 and the induced air flow, which mixes with this flow of air ejected. However, too great a length of the cross section of the aerodynamic tube 8 poses a problem of packaging of the ventilation device 2. In particular, the size of the heat exchange module can then be too large compared to the place that is available in the motor vehicle in which it is intended to be mounted. The packaging of the heat exchange module or the ventilation device can also be problematic in this case.

Moreover, as illustrated in FIG. 7, the second rectilinear portion 38a of the first profile 42 and the portion 38b of the rectilinear portion 48 of the second profile 44 facing it are parallel. For example, the distance f between this second rectilinear portion 38a and the portion 38b of the rectilinear portion 48 of the second profile 44 may be greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm. mm.

FIG. 7 further illustrates that the cross section (or geometrical section) of the aerodynamic tube 8 delimits a passage section S for the flow of air passing through the aerodynamic tube 8. This passage section S is here defined by the walls of the aerodynamic tube 8 and the segment extending in the alignment direction of the aerodynamic tubes 8 between the second profile 44 and the end of the end 51 of the inner lip 40b. This passage section may have an area greater than or equal to 150 mm 2, preferably greater than or equal to 200 mm 2, and / or less than or equal to 700 mm 2, preferably less than or equal to 650 mm 2. A passage section of the air flow in the aerodynamic tube 8 limits the pressure losses which would have the consequence of having to oversize the turbomachine used to obtain an air flow ejected by the desired opening 40. However, a large passage section induces a large size of the aerodynamic tube 8. Thus, with fixed pitch aerodynamic tubes, a larger passage section may affect the passage section of the induced air flow between the aerodynamic tubes 8 , thus not making it possible to obtain a satisfactory total flow of air directed towards the heat-transfer tubes 4.

In order to block as little as possible the flow of air towards the heat-transfer tubes 4 and the fins, the ventilation device 2 provided with such aerodynamic tubes 8 is advantageously arranged so that each aerodynamic tube 8 is vis-à-vis 4f of the front face connecting the first 4a and second 4b planar walls of a heat pipe 4 corresponding. More particularly, the trailing edge 38 of each aerodynamic tube 8 is included in the volume defined by the first and second longitudinal plane walls of the heat pipe 4 corresponding.

Preferably, the second rectilinear portion 38a of the first profile and the rectilinear portion 48 of the second profile 44 are respectively contained in the same plane as the first longitudinal plane wall and the second longitudinal plane wall of the heat pipe 4 corresponding.

In particular, the distance f between the second straight portion 38a of the first profile 42 and the portion 38b of the rectilinear portion 48 of the second profile 44 facing it is substantially equal to the distance separating the first longitudinal wall and the second longitudinal wall. heat transport tube 4 vis-à-vis which the aerodynamic tube 8 is disposed. For example, this distance f is greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm.

In other embodiments, the distance f between the second rectilinear portion 38a of the first profile 42 and the portion 38b of the rectilinear portion 48 of the second profile 44, which faces it, may, however, be less than the distance separating the first longitudinal wall and the second longitudinal wall of the heat transport tube vis-à-vis the aerodynamic tube 8 is disposed.

Two heat transfer tubes 4 may be contained in the volume defined by the air passage defined by two aerodynamic tubes 8 neighbors. However, it can be envisaged that a single heat-transfer tube 4, or three or four heat-transfer tubes 4 are contained in this volume. Conversely, it can be envisaged that an aerodynamic tube 8 is disposed opposite each heat-carrying tube 4.

In the examples of FIGS. 8, 9 and 10, the aerodynamic ducts 8 are substantially rectilinear, parallel to each other and aligned so as to form a row of aerodynamic tubes 8. However, the first and second profiles 42, 44 of each aerodynamic tube 8 are, according to these examples, symmetrical with respect to a plane CC, or rope plane, passing through the leading edge 37 and the trailing edge 38 of each aerodynamic tube 8.

As the first and second profiles 42, 44 are symmetrical, each of these profiles 42, 44 is provided with an opening 40. Thus, at least a first opening 40 is formed on the first profile 42, which is configured so that a the air flow exiting the first opening 42 flows along at least a portion of the first profile 42. Likewise, at least a second opening 40 is present on the second profile 44, which is configured so that a airflow exiting the second opening 40 flows along at least a portion of the second profile 44. As for the example of Figure 7, this can be achieved here by implementing the Coanda effect.

For the same reasons as those given for the example of FIG. 7, the distance c between the leading edge 37 and the trailing edge 38 can also, in these examples, be greater than or equal to 50 mm and / or lower. or equal to 80 mm. In particular, the length c may be equal to 60 mm.

The openings 40 are similar to those of the example of FIG. 7. In particular, the distance e between the inner and outer lips 40b and 40a of each opening 40 may be greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, more preferably greater than or equal to 0.7 mm, and / or less than or equal to 2 mm, preferably less than or equal to 1.5 mm, more preferably less than or equal to 0.9 mm and more preferably still less than or equal to 0.7 mm.

The fact that the profiles 42, 44 are symmetrical with respect to the chord plane CC passing through the leading edge 37 and the trailing edge 38 of the aerodynamic tube 8 makes it possible to limit the obstruction to the air flow between the device of FIG. ventilation 2 and the heat pipes 4, while creating more air passages in the volume available in front of the heat pipes 4.

In other words, contrary to the embodiment of FIG. 7, an ambient air passage is created between each pair of adjacent aerodynamic tubes 8 made according to one of FIGS. 8 to 10.

The pitch between two adjacent aerodynamic tubes 8 may, in this case, be greater than or equal to 15 mm, preferably greater than or equal to 20 mm, more preferably greater than or equal to 23 mm and / or less than or equal to 30 mm, preferably less than or equal to 25 mm, more preferably less than or equal to 27 mm. Indeed, if the pitch between the aerodynamic tubes 8 is lower, the induced air flow is limited by a passage section between the weak aerodynamic tubes. On the contrary, if the pitch is too large, the ejected airflow does not create an induced air flow over the entire pitch between the neighboring aerodynamic tubes.

The pitch between two adjacent aerodynamic tubes 8 can in particular be defined as the distance between the center of the cross section of two adjacent aerodynamic tubes 8 or, more generally, as the distance between a reference point on a first aerodynamic tube 8 and the point corresponding to the reference point, on the nearest aerodynamic tube 8. The reference point may especially be one of the leading edge 37, the trailing edge 38 or the top of the curved portion 50.

The distance between the aerodynamic tubes 8 and the heat-transfer tubes 4 can in particular be chosen greater than or equal to 5 mm, preferably greater than or equal to 40 mm, and / or less than or equal to 150 mm, preferably less than or equal to 100 mm. . Indeed, the peak speed of the air velocity profile in the vicinity of the profile, tends to be reduced by departing from the opening 40 in the aerodynamic tube. An absence of peak reflects a homogeneous mixture of the air flow ejected by the opening 40 and the induced air flow. It is preferable that such a homogeneous mixture is made before the airflow reaches the aerodynamic tubes. Indeed, a flow of air incident on the heat transfer tubes, heterogeneous, does not allow optimal cooling of the heat pipes and induces greater pressure losses. However, the distance between the aerodynamic tubes and the heat transfer tubes is preferably contained to limit the size of the cooling module.

In the example illustrated in FIG. 8, the trailing edge 38 is formed by the apex joining two straight symmetrical portions 60 of the first profile 42 and the second profile 44 of each aerodynamic tube 8. According to the variant of FIG. trailing edge 38 is the point of the cross section of the aerodynamic tube 8 located closest to the heat exchanger. In other words, the angle formed by the two rectilinear portions 60 is less than 180 °, especially less than 90 °.

On the contrary, in the variant of Figure 9, the trailing edge 38 is disposed between the two straight portions 38a, 38b of the first and second profiles 42, 44. In other words, the angle formed by the rectilinear portions 60 is here greater than 90 °, in particular greater than 180 °.

In the example illustrated in FIG. 10, the first and second profiles 42, 44 of the aerodynamic tube 8 converge towards the trailing edge 38 so that the distance separating the first and second profiles 42, 44 decreases strictly towards the leak 38 from a point of these first and second profiles 42, 44 corresponding to the maximum distance h between these two profiles, these points of the first and second profiles 42, 44 being downstream of the openings 40 in the direction of flow the flow of air ejected through the opening 40. Preferably, the first and second profiles 42, 44 each form an angle of between 5 and 10 ° with the symmetry rope CC of the cross section of the aerodynamic tube 8.

As a result, contrary to the example of FIG. 8, the aerodynamic profile of FIG. 8 does not include a portion delimited by first and second parallel opposed plane walls. This has the advantage of limiting the drag along the aerodynamic profile of the aerodynamic tube 8.

For example, the maximum distance h between the first profile 42 and the second profile 44 may be greater than or equal to 10 mm and / or less than or equal to 30 mm. In particular, this maximum distance h can be equal to 11.5 mm.

Finally, FIG. 11 diagrammatically illustrates a variant of the heat exchange module 10 of FIG. 1. According to this variant, the heat exchange device 1 comprises three distinct radiators 1a, 1b, such that, while the radiators 1a and 1b are substantially superimposed, the third radiator is of reduced size and extends only in the lower part of the heat exchange device 1. In this case, it may be advantageous to combine the absence of ejection of an air flow by certain ducts 8 to a position of these ducts 8 limiting or even preventing air from passing through these ducts 8. To do this, the ducts 8 advantageously have an oblong shape. The ducts 8 are pivotable about a respective longitudinal axis between a first effective position, in which the ducts are oriented so that the air they eject is directed towards the heat exchange device and allowing a passage of air between the ducts 8 so as to form an induced air flow. On the contrary, in a second position, reached by pivoting from the first position, the ducts 8 limit or even prevent the passage of air between them, in the direction of at least a portion of the heat exchanger. Thus, advantageously, the ventilation device can be configured so that in its part facing the heat exchanger that needs cooling most often, or even always, in the position where the openings of the ducts 8 are oriented towards this part of the heat exchanger 1, the ducts 8 then being supplied with air by the air propulsion device, via the air intake manifold 12. On the contrary, the part of the heat exchanger placed vis-à-vis the ventilation device, may correspond to that which is not supplied with air by the ventilation device when the flow and / or the pressure of the air flow emitted by this- it is relatively small. In this case, where these ducts are not supplied with air, they can be pivoted to limit or prevent the passage of air through between the ducts, so as to improve the aerodynamic properties of the vehicle on which the exchange module of heat is mounted. The invention is not limited to the exemplary embodiments presented and other embodiments will become clear to those skilled in the art. In particular, the different examples can be combined, as long as they are not contradictory.

Furthermore, the indicated examples of means for selectively interrupting a fluid communication between at least some ducts and the air propulsion device to interrupt this fluid communication in an air intake manifold. Alternatively, however, the fluid communication can be selectively interrupted in each tube. In particular, the means for selectively interrupting a fluid communication between at least some ejection ports and the air propulsion device may consist of means for closing the section of a ventilation tube, whose position in the The tube can be controlled in a manner substantially similar to what has been described with respect to the shutter in the air intake manifold. According to another variant, a shutter of the ventilation tube ejection orifices can be provided which is selectively moved to control the fluid communication between the ejection ports and the air propulsion device.

Also, in the examples described, the means for selectively interrupting the fluid communication between at least some ejection ports and the air propulsion device are passive. Such a solution is preferred because it requires no power supply or complex connection. Alternatively, these means are active. Such an active solution may in particular make it possible to control the fluid communication between the ejection orifices and the air propulsion device, independently of the pressure of the air flow supplied by the air propulsion device. The active means may take the form of one or more solenoid valves and / or one or more pneumatic valves.

Finally, according to a non-illustrated embodiment, the air propulsion device can be received in one of the air intake manifolds or in each air intake manifold.

Claims (9)

Ventilation device (2) for generating a flow of air towards a motor vehicle heat exchanger (1), comprising ducts (8) for supplying air flow by at least one air propulsion device, each duct (8) having at least one opening (16; 40) for ejecting an air flow passing through said duct (8), substantially towards said heat exchanger (1), the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said air propulsion device, said ventilation device (2) further comprising minus one air intake manifold (12), each duct opening (8) at one of its ends into an orifice (14) separate from the at least one air intake manifold (12), the ducts (8) ) being intended to be fed with a flow of air by said at least one air propulsion device, via the at least one air intake manifold (12), said at least one ejection opening (16; 40) conduits being distinct from the ends of the corresponding conduit, said at least one opening (16; 40) being located outside the at least one air intake manifold (12). 2. Ventilation device according to claim 1, wherein the means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said at least one propulsion device comprise means for closing: - at least some openings (14) of the air collector; and / or - a section of the at least one air collector (12); and / or - at least some ejection openings (16; 40). 3. Ventilation device according to one of the preceding claims, wherein the means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said air propulsion device are passive, the means adapted for selectively interrupting a fluid communication between at least some ejection openings (16; 40) and said propulsion device being preferably controlled by an air flow and / or an air pressure. Ventilation device according to claim 3, wherein the at least one air intake manifold (12) is substantially tubular in shape, preferably cylindrical, and wherein the means adapted for selectively interrupting a fluid communication between at least some ejection openings (16; 40) and said at least one air propulsion device comprise a shutter (102), the shutter (102) having a section substantially complementary to the cross section of said at least one collector air inlet (12), the shutter (102) being movable in said at least one air collector (12). Ventilation device according to claim 4, wherein the shutter (102) is movably mounted against the action of a return spring (104), the return spring (104) preferably having a stiffness greater than or equal to at 5 N / m and / or less than or equal to 50 N / m. A ventilation device according to any one of the preceding claims, wherein the means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said air propulsion device comprise at least a valve (202), preferably a rocker flap, adapted to close at least one orifice (14) of the at least one air collector (12), the flip flap preferably being pivotally mounted against the action of a return spring. The ventilation device according to claim 1 or 2, wherein the means adapted to selectively interrupt fluid communication between at least some ejection openings (16; 40) and said air propulsion device are active. 8. Ventilation device according to claim 7, wherein the means adapted to selectively interrupt a fluid communication between at least some ejection openings and said air propulsion device comprise at least one of a solenoid valve and a valve pneumatic. 9. Ventilation device according to any one of the preceding claims, wherein at least some ducts (8) are pivotable, preferably around a respective longitudinal axis, the ducts (8) preferably having an oblong section such as the ducts (8) allow the passage of air between the ducts in a first position and the ducts (8) limit or even prevent the passage of air between the ducts (8) in a second position reached by pivoting the ducts ( 8) from the first position.