CN106081123B - An ice crystal detector probe and a complex icing condition detector including the probe - Google Patents

Abstract

The invention belongs to the field of aircrafts, and discloses an ice crystal detector probe and a complex icing condition detector. The ice crystal detector probe comprises a first section and a second section arranged in sequence from top to bottom; the first section and the second section are in smooth connection; the outer surface of the first section is in a shape suitable for separating liquid droplets from ice crystals in airflow and bearing impact of the ice crystals; a heating device and a plurality of fine particle impact sensors are installed inside the first section; and the second section is a heat insulation layer so as to avoid heat exchange between the first section and external probe installation equipment. The complex icing condition detector comprises the ice crystal detector probe and an icing detector probe. Liquid water in airflow does not generate obvious impact on the windward side of the probe, the ice crystals generate pulse impact on the windward side of the icing detector probe, and therefore the ice crystals and the liquid water droplets are distinguished and accurate detection of icing of the ice crystals can be achieved.

Description

An ice crystal detector probe and a complex icing condition detector including the probe

technical field

The invention belongs to the field of aircraft, and more specifically relates to an ice crystal detector probe and a complex icing condition detector including the probe.

Background technique

In the field of aircraft icing safety protection, ice crystals refer to particles with a median mass dimension (MMD) in the range of 50-200 microns (equivalent spherical size) formed by freezing water. The threat of ice crystal particles to flight is much more serious than that of rain. When an aircraft encounters an ice crystal cloud, it is easy to produce dry ice. Once ice accumulation occurs during flight, the aerodynamic performance of the aircraft will deteriorate, and the streamline shape will also be damaged. The roughness increases greatly, which increases the frontal resistance, reduces the lift and thrust, affects the stability of the aircraft, makes it difficult to maneuver, and in serious cases will cause an aircraft crash. The height of serious icing is usually when the outside temperature is around -5°C to -15°C. At this time, the ice crystals have high viscosity and are easy to attach to the surface of the body.

In terms of ice crystal detection research, the main method in the world is to detect by aircraft health parameters or particle detectors. The US company Droplet Measurement Technologies has proposed a particle detector based on optical fiber, which can measure the particle size of water droplets, ice crystals, dust haze, etc. , but there are problems such as the instrument is too expensive, precise and cumbersome. Freer and others in the United States proposed a cloud probe technology based on the principle of backscattering, which distinguishes water droplets, dust haze, and ice crystals through the characteristics of particle scattering. This method has good development prospects, but the current detection stability is poor, and It is difficult to realize the application. NASA intends to use the health parameters of the aircraft engine to invert the ice crystal adhesion on the engine surface. The inversion algorithm can judge the ice crystal adhesion well under certain fixed working conditions, but it is difficult to distinguish the ice crystal on the engine in actual flight. The influence and the influence of the throttle valve action on the parameters.

The invention patent application with the application publication number CN103323849 A uses airborne radar to complete the ice crystal measurement of the cloud layer. An airspace region having ice crystals may be identified if at least one of the flight conditions is present concurrently with an identified radar echo having an echo level signal strength less than a radar echo sensitivity threshold level. The invention patent with the authorized publication number CN102830107 B utilizes the difference between the solid and liquid Raman scattering frequency shifts of water, uses lasers as the emission source, and normalizes the Raman scattering signals of water through the 4 detection channels of the optical receiving part to realize the detection of The phase state of the water in the cloud is detected, and finally the solid and liquid content of the water in the cloud is inverted through the solid and liquid Raman scattering principle of water. Although such a device can realize the identification and detection of ice crystals, its disadvantages are: the detector has a complex structure, a large volume and relatively difficult processing.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides an ice crystal detector probe and a complex icing condition detector including the probe. impact, and the ice crystals have a pulse impact on the windward side of the ice crystal detector probe, so as to realize the distinction between ice crystals and liquid water droplets, so that accurate detection of ice crystal freezing can be realized.

In order to achieve the above object, according to the present invention, an ice crystal detector probe is provided, which is characterized in that it includes a first section and a second section arranged in sequence from top to bottom, the first section and the second section smooth connection, where

The outer surface of the first section is set in a shape suitable for separating liquid water droplets and ice crystals in the airflow and accepting the impact of the ice crystals. In addition, the outer surface of the first section includes a windward side close to the airflow and a side facing away from the airflow, which is in line with the The leeward side connected to the windward side, the area of the windward side can meet the impact of ice crystals, and the windward side can make the airflow flowing through the first section generate a vortex at the windward side, thereby taking away the liquid water in the airflow, the leeward side The surface is used to make the boundary layer separation of the nearby air flow;

A heating device and a plurality of particle impact sensors are installed in the first section, the heating device is used to keep water and ice from accumulating on the ice crystal detector probe, and the particle impact sensor is used to detect the pressure generated by ice crystals hitting the windward side Variety;

The second section is a thermal insulation layer to avoid heat exchange between the first section and the external probe installation equipment.

Preferably, the windward surface of the first section is a trapezoidal plane perpendicular to the airflow direction;

The leeward surface of the first section is in the shape of a cone-like surface with a small top and a large bottom;

The top surface of the first segment is an arcuate plane.

Preferably, the first section has two windward surfaces, each of which is a trapezoidal plane with an acute angle to the airflow direction, and the angle between the two windward surfaces is also an acute angle;

The leeward surface of the first section is a cone-like surface, and it is smoothly connected with the windward surface;

The top surface of the first section presents a drop-like plane.

Preferably, the heating device is heated by gas heating or electric heating, or it is made of a composite material with heating function.

Preferably, the second section of heat insulation layer is insulated by air cooling or water cooling, or it is made of a composite material with heat insulation function.

Preferably, the ice crystal detector is in the shape of a small top and a large bottom, so as to maintain stability during flight.

According to another aspect of the present invention, a detector for complex icing conditions is also provided, which is characterized in that it includes an ice crystal detector head, and the ice crystal detector head is installed on the ice crystal detector head.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

1. The present invention has simple structure, small volume and easy processing;

2. The present invention can be used on airborne, and can detect icing conditions in real time;

3. The shape of the ice crystal detector probe of the present invention makes the liquid water in the air flow not produce obvious impact on the windward side of the probe, and the ice crystals generate pulse impacts on the windward side of the ice crystal detector probe, thereby realizing the distinction between ice crystals and liquid water droplets, like this, Accurate detection of ice crystal freezing can be realized, and liquid water droplets with different median volume diameters and ice crystals with different median mass sizes in the airflow can be effectively detected.

Description of drawings

Fig. 1 is the front view of ice crystal detector in the embodiment 1 of the present invention;

Fig. 2 is the plan view of the ice crystal detector of embodiment 1 of the present invention;

Fig. 3 is a schematic structural view of the ice crystal detector of Embodiment 1 of the present invention installed on the ice detector;

Fig. 4 is the front view of the ice crystal detector in Embodiment 2 of the present invention;

Fig. 5 is a top view of the ice crystal detector in Embodiment 2 of the present invention;

Fig. 6 is a structural schematic view of the ice crystal detector according to Embodiment 2 of the present invention installed on the ice detector.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

Example 1

Referring to Figures 1 to 3, an ice crystal detector probe includes a first section I and a second section II arranged sequentially from top to bottom, the first section I and the second section II are smoothly connected, wherein ,

The outer surface of the first section I is set in a shape suitable for separating liquid water droplets and ice crystals in the airflow and accepting the impact of the ice crystals. In addition, the outer surface of the first section I includes a windward side a close to the airflow and a side facing away from the airflow, The leeward side b connected to the windward side a, the area of the windward side a can meet the impact of ice crystals, and the windward side a can make the airflow flowing through the first section I generate a vortex on the windward side a, thereby taking away Liquid water in the airflow, the leeward side b is used to separate the boundary layer of the nearby airflow, so as to avoid water and ice accumulation on the rear side of the probe. This requires that the water droplets in the air flow have a shorter residence time on the outer surfaces of the sides. Therefore, the outer surfaces of the sides should have a relatively short length to avoid icing.

A heating device and a plurality of particle impact sensors c are installed in the first section I, the heating device is used to keep water and ice from accumulating on the ice crystal detector probe, and the particle impact sensor c is used to detect the impact of ice crystals on the windward side The pressure change generated by a, the particle impact sensor c can distinguish between ice crystals and a small amount of liquid water droplets hitting the windward side a, and can detect parameters such as the quality and speed of ice crystals.

The second section II is a heat insulation layer to avoid heat exchange between the first section I and the external probe installation equipment.

When the high-speed air flow encounters an obstacle (the ice crystal detector probe), a vortex will be generated in front of the probe, so that the air flow will flow along the windward side a of the probe to the side, and the vortex generated by the air flow can take away a large number of dispersed liquid water droplets in the air flow , while solid ice crystals will still hit the probe directly.

Specifically, the liquid water droplet hits the windward side a, and the water droplet is broken. Due to the fluidity of the liquid, the windward side a will detect a weaker signal with a slower gradient change, and then the water droplet will flow away along the probe. When the ice crystal hits the windward side a, a relatively strong pulse signal will be detected on the windward side a, and at the same time the ice crystal will be bounced off, and as the air flow flows, the ice crystal will hit the windward side a many times, and the windward side a will detect Gradually weakening pulse signal. According to the type and size of the signal, liquid water droplets and ice crystals can be distinguished, and parameters such as the quality and speed of ice crystals can be calculated. Among them, the signal processing algorithm can be obtained through experiments. By simulating the impact characteristics of various liquid water droplets and ice crystals, a series of environmental conditions, ice crystal parameters and the relationship between the detector response can be obtained.

Further, the windward surface a of the first section I is a trapezoidal plane perpendicular to the airflow direction k; the windward surface a of the first section I is used to collide with the ice crystals in the airflow, and its shape is small enough to be compatible with An appropriate amount of ice crystals produces a trapezoidal shape of impact, thus having a high detection performance for ice crystals.

The leeward surface b of the first section I is in the shape of a cone-like surface with a small top and a large bottom;

The top surface of the first segment I is an arcuate plane.

Further, the heating device is heated by gas heating or electric heating, or it is made of a composite material with heating function such as a graphene heating film.

Further, the heat insulation layer of the second stage II is insulated by air cooling or water cooling, or it is made of a composite material with heat insulation function such as chemically cross-linked polyethylene foam material.

Further, the ice crystal detector is in the shape of a small top and a big bottom, so as to keep the stability during the flight.

According to another aspect of the present invention, there is also provided a detector for complex icing conditions, including the above-mentioned ice crystal detector probe e, the ice crystal detector probe e is installed on the icing detector probe f, the icing detector e can adopt the icing detector whose patent number is CN201010229387.X. The second section II of the ice crystal detector probe e is closely attached to the icing detector probe that can distinguish normal water droplets and supercooled large water droplets in the airflow. The icing condition detector is connected to the outer surface of the aircraft through a bracket. Such a complex icing condition detection system combination enables effective detection of liquid water droplets with different median volume diameters and ice crystals with different median mass sizes in the airflow.

Example 2

Referring to Figures 4 to 6, the difference between this embodiment and Embodiment 1 is mainly that the shape of the first section I is different. The first section I of this embodiment has two windward surfaces a, each of which is windward. Surface a is a trapezoidal plane with an acute angle to the airflow direction k, and the angle between the two windward surfaces a is also an acute angle;

The leeward surface b of the first section I is a cone-like surface, and it is smoothly connected with the windward surface a. It has a certain streamline shape and is smoothly connected with the windward surface a, so that the influence of the probe on the environmental flow field can be reduced

The top surface of the first section I presents a drop-like plane.

According to another aspect of the present invention, there is also provided a detector for complex icing conditions, including the above-mentioned ice crystal detector probe e, the ice crystal detector probe e is installed on the icing detector probe f, the icing detector e can adopt the icing detector whose patent number is CN201010229387.X. The second section II of the ice crystal detector probe e is closely attached to the icing detector probe that can distinguish normal water droplets and supercooled large water droplets in the airflow. The icing condition detector is connected to the outer surface of the aircraft through a bracket. Such a complex icing condition detection system combination enables effective detection of liquid water droplets with different median volume diameters and ice crystals with different median mass sizes in the airflow.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (7)

1. An ice crystal detector probe is characterized in that it comprises a first section (I) and a second section (II) arranged in sequence from top to bottom, and the first section (I) and the second section (II) Smooth connection, where, The outer surface of the first section (I) is set in a shape suitable for separating liquid water droplets and ice crystals in the airflow and accepting the impact of the ice crystals. In addition, the outer surface of the first section (I) includes a windward surface (a ) and the leeward side (b) connected to the windward side (a) away from the airflow, the area of the windward side (a) can meet the impact of ice crystals, and the windward side (a) can make the flow through the first section The airflow of (I) generates a vortex at the windward side (a), thereby taking away the liquid water in the airflow, and the leeward side (b) is used to separate the boundary layer of the nearby airflow; A heating device and a plurality of particle impact sensors (c) are installed in the first section (I), and the heating device is used to keep water and ice from accumulating on the ice crystal detector probe, and the particle impact sensor (c) is used Used to detect pressure changes caused by ice crystals hitting the windward side; The second section (II) is a heat insulation layer to avoid heat exchange between the first section (I) and the external probe installation equipment. 2. ice crystal detector probe as claimed in claim 1, is characterized in that, The windward surface (a) of the first section (I) is a trapezoidal plane perpendicular to the airflow direction (k); The leeward surface (b) of the first section (I) is in the shape of a cone-like surface with a small top and a large bottom; The top surface of the first segment (I) is an arcuate plane. 3. ice crystal detector probe as claimed in claim 1, is characterized in that, The first section (I) has two windward surfaces (a), each of which is a trapezoidal plane with an acute angle to the airflow direction (k), and the two windward surfaces The included angle is also an acute angle; The leeward surface (b) of the first section (I) is a cone-like surface, and it is smoothly connected with the windward surface (a); The top surface of the first section (I) presents a drop-like plane. 4. The ice crystal detector probe according to claim 1, wherein the heating device is heated by gas heating or electric heating, or it is made of a composite material with heating function. 5. The ice crystal detector probe according to claim 1, characterized in that, the second section (II) heat insulation layer adopts air cooling or water cooling for heat insulation, or it adopts a composite material with heat insulation function production. 6. The ice crystal detector probe according to claim 1, characterized in that, the ice crystal detector has a shape of small top and large bottom, so as to maintain stability during flight. 7. A detector for complicated icing conditions, characterized in that it comprises the ice crystal detector probe according to any one of claims 1 to 6, and the ice crystal detector probe is installed on the ice crystal detector probe.