US2918254A

US2918254A - Turborunner

Info

Publication number: US2918254A
Application number: US507407A
Authority: US
Inventors: Hausammann Werner
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-05-10
Filing date: 1955-05-10
Publication date: 1959-12-22
Anticipated expiration: 1976-12-22

Description

Dec. 22, 1959 Filed May 10, 1955 w. HAUSAMMANN 2,918,254

TURBORUNNER 6 Sheets-Sheet 1 INVEN T OR.

Werner Hdusammwnn BY MM 6. 51mm Dec. 22, 1959 w. HAUSAMMANN TURBORUNNER Filed May 10, 1955 6 Sheets-Sheet 2 2 mm a m vm m m u n M Q 2E Dec. 22, .1959

Filed May 10, 1955 FIG.5

W. HAUSAM MANN TURBORUNNER 6 Sheets-Sheet 3 INVENTOR.

W cm er Hqusarmmcm n BY MM s. swam aqt' Dec. 22, 1959 w. HAUSAMMANN 2,918,254

TURBORUNNER Filed May 10, 1955 6 Sheets-Sheet 4 36 3S INVENTOR.

Werner Hausammann BY Dec. 22, 1959 w. HAUSAMMANN TURBORUNNER Filed May 10, 1955 FIG. 7

6 Sheets-Sheet 5 l N VE N TOR.

Werner wmmn mam, s. smmm,

Dec. 22, 1959 w. HAUSAMMANN 2,918,254

TURBORUNNER Filed May 10, 1955 6 Sheets-Sheet. 6

VIII/1W 76 1 N VEN TOR y CI Hflusammnn United States Patent TURBORUNNER Werner Hausammann, Zurich, Switzerland Application May 10, 1955, Serial No. 507,407 Claims priority,application Switzerland May'10,19 54 12 Claims. (Cl. 253-65) My present invention relates to improvements in turbomachine rotors, in particular to the shaping of the rotor parts swept by the flow of the operating fluid. Examples of such machines are pumps, compressors and blowers.

The energy change in the rotors of turbomachines may concern either the pressure or the velocity. Fundamentally, the following possibilities exist: change of the flow velocity; flow deflection; centrifugal eflects; exploitation of compression shocks at supersonic flow. Some of the requirements inherent in the construction of high-grade turbomachines with respect to the shaping of the fluidimpinged rotor zones, are: the exchange of energy shall be brought about with a minimum of frictional expense; the energy convertible in each stage shall be as high as possible and be variable within as large a range as possible without giving origin to unstable flow conditions; the runners shall be able to withstand high mechanical stresses, often at high temperatures; the natural frequencies of the runner elements shall be outside of the excitation range; the runners shall be economically produceable in a simple way and manner, also from poorly castable or machinable materials.

These requirements so far could be met only in narrow limits by the known constructions and designs of turborunners.

The best efficiencies in energy exchange are obtained today in the case of runners provided with airfoil blades, which act in the case of runners provided with airfoil blades, which act mainly through deflection. Their disadvantages are numerous: the steady range in which the energy conversion may fluctuate, especially in the case of axial compressors, is defined within narrow limits by reason of the sensitivity of the profiles as to variations of the direction of flow; the pressure ratios attainable, especially in the case of compressors, are very limited, having regard to the flow separation at the blades; the blades always have fiexural and torsional natural frequencies arising within the range of typical interferential vibrations of the operating media, which requires measures unfavorable to efliciency such as damping through foot play, bind ing wires, a raise in frequency'through thickened profiles; high manufacturing costs by reason of individual m'arlu facture of each blade and detachable connection to the runner, high mechanical stresses in the junctures; additional friction losses caused by the hub conditions at higher pressure ratios which require a high number of blades and small lengths thereof; difficulties in the control of the forces arising in supersonic flow.

These disadvantages also are found substantially in runners with superimposed centrifugal effect, such as in radial blowers and Francisturbines, which for the major portion, however, do not quite attain the high efliciency and throughput ofthe runners operatingpurely with de flection. i

It has been tried before to provide runners which avoid single ones of the disadvantages mentioned. For" example, staggered profiles have been provided for higher pressure ratios, or the blades have been made rotatable 2,918,254 Patented Dec. 22, 1959 as in Ka'planturbines. For the control of critical Mach numbers, blades have been proposed with swept back edges. All of these constructions, however, are bound to the flow conditions on blade profiles. Turborunner constructions known so far, in which the energy conversion is based on flow deflection, may substantially be traced back to the flow phenomenon about blade profiles.

My present invention, inthe case of compressors, provides an increased runner stage output and avoids the disadvantages of blading operating through flow deflection.

The turborunner as disclosed by the present invention comprises at least one duct constituted by partition areas, a hub surface and an exterior surface, and such turborunner is characterized in that at least one of said surfaces in at least one section at right angles to the axis of rotation is unequally spaced from said axis along the intersecting curve.

The partition areas between the ducts may be formed by deflection blades, whereby a deflection yet is superimposed onto the velocity change. All of the ducts, or only groups thereofmay be congruent.

In the case of compressors, the runner may be impinged upon with supersonic speed, whereby pronounced pressure increments are obtainable by virtue of arising compression shocks.

The duct defining surfaces may be coolable so as to make permissible extreme thermal loads.

For use in compressors, means may be provided for boundary-layer removal by suction, which renders possible higher pressure ratios and higher efliciencies.

On the other hand, separations may be prevented or desired cross-sectional changes be effected by fluid injection into the duct (slotted-wing principle).

Various forms of the invention are shown, by way of example, in the accompanying drawings, in which Fig. 1 is a perspective view of a runner portion,

Fig. 2 is a'section on the line 2-2 of Fig. 1 through a runner at right angles to the axis of rotation,

Figs. 3a and 3b illustrate longitudinal sections through the runner taken in Fig. 2on the line 3a3a for curve D and on the line 3b3b for curve B in Figure 31),

Figs. 4 and 5 show an embodiment of the runner in a stage of an axial compressor in a longitudinal section, and in a cross-section taken on the line 5-5 of Fig. 4, respectively,

Fig. 5a shows a detail in section,

Fig. 6 illustrates a radial compressor, the casing being shown in section and the runner in elevation,

Fig. 6a shows a detail in section taken on line 6a6a in Fig. 7,

Fig. 7" shows a radial turbine, the casing being in section and the runner in elevation, I Fig. 811 schematically shows the forces acting on the duct Wall's,

Fig. 8 shows a detail in section, and

Figs. 9 to 14 show typical shapes of hub surfaces and exterior surfaces.

Runner 1 in Fig. 1 comprises ducts 2. formed by the partition walls 3 With the partition areas 3' and 3' a hub surface 4 and an exterior surface (not shown) which may be constituted by the turbomachine-casing or a special shroud secured to said partition walls.

Planes at right angles to the runners axis of rotation 5 intersect for example the hub surface on curves" 6 which, with respect to said axis, are nonspheroidal, with the exception of the runner inletand outlet portions 7 and 81 The curves D and E of hub surface 4 produced by the longitudinal section may have any form. Usual 1y constructions are'employed, depending on the purpose, asshow'n ihFigs. 9 to 13. l p

A SihgIe s'tag e axial compressor incorporating the features of the present invention may be of the following construction and mode of operation (Figs. 4 and 5):

Fig. 4 shows casing, runner and stator. A fluid which is to be compressed, enters the machine from the left past struts 11 which support a forward runner bearing 12.. The fluid is seized by a runner 13 which through separating walls 14 is subdivided into a plurality of ducts which in the peripheral direction are defined by hub surfaces 15 and exterior surfaces, for example, in form of a casing 24 or of a shroud band (not shown). Since the crosssection at the right of runner 13 is larger than that at the left, the fiuid is retarded therein. Such delay results in a pressure rise, according to the formula of Bernoulli. The duct acts as rotary diflusor. The compressed fluid subsequently enters into a stator 16 in which the crosssection is still further enlarged, and the velocity is further reduced and converted into pressure in a stationary diffusor 17. In the latter are disposed struts 18 which carry an exterior portion 19 of a runner labyrinth seal 20 which has as large a diameter as possible for the purpose of decreasing the axial thrust. The struts 18 by means of a wall 21 hold the rearward runner bearing, and a collar 22 on a runner shaft 23 takes up the axial thrust arising from the difference in cross-section between inlet and outlet of runner 13. Mechanical energy is supplied through shaft 23. Rotor, stator 16 and ditfusor 17 are enclosed by the casing 24. Stator 16, which when using only one runner 13 would not be absolutely necessary, is necessary for a plural-stage construction in which another runner is provided downstream of mem'

bers

13 and 16.

Fig. 5 shows a section on the line AA in Fig. 4. The invisible penetration curves of the surfaces 15 and the partition walls 14 are shown in dotted lines. The runner rotates counter-clockwise.

The machine illustrated in Figs. 4 and 5 could readily be used as turbine. The flow in such case would have to take place from the right to the left in Fig. 4, and the rotor would rotate clockwise in Fig. 5.

The machine shown in Figs. 4 and 5 may also be used as supersonic compressor. The flow conditions in such case are similar to those described above. In lieu of a steady velocity reduction in the diffusor, there arise compression shocks which are accompanied by an abrupt rise in pressure, density and temperature.

Fig. 6 shows a radial blower, the scroll case being shown in section, and the runner in elevation. The fluid to be delivered flows through a feed pipe (not shown) into an entrance room 31 which surrounds a hub 32, and thence into the ducts 33 which are formed by partition walls 34 and hub surfaces 35. Fig. 5a shows such a cell in section. The cross-section is enlarged in the ducts 33. The fluid is delayed under a pressure rise. After leaving runner 36, the fluid is still further delayed in the scroll case 37. Since the ducts are gradually enlarged divergingly owing to the construction of the partition walls 34, a further pressure rise is superimposed on to the pressure rise brought about by the shape of hub surface 35. The same machine may be used for the conveyance of liquids.

Fig. 7 shows a turbine, the case being shown in section, and the runner in elevation. The operating fluid enters vanes 43 through an annular chamber 41 of a casing 42.

Said vanes produce a twist or spin in the fluid so that the latter flows into a runner 44 under the exit angle of the vanes. The runner ducts are formed by the hub faces 45, the partition walls 46 and the exterior surface 42. The short, nozzle-like hub face 45 is shown in Fig. 6a which depicts the cross-section of a runner duct. Additionally to the partition walls 46, short blades 47 yet are provided. Owing to the shape of hub face' 45, the fluid is highly accelerated and flows into an annular chamber 48 in vicinity of a hub 49 and thence forwardly in an axial direction. The runner rotates clockwise.

Fig. 8 which schematically shows a duct in perspective,

serves for explaining the mode of energy conversion on surface 55. The duct is formed by the

partition walls

51 and 52, and the hub or exterior surfaces 53 to 55. Since we consider here the ducts of a compressor, i.e. power is delivered from the mechanical system to the operating fluid, the latter flows from left to right, i.e. from the smaller into the larger cross-section. There is no change in the flow condition within the range of surface 53. When, now, the fluid flows into the range of the inclined surface 55 which is inclined with respect to the cellendfaces, the velocity is reduced on account of the increase of the duct cross-section, and the pressure rises as kinetic energy is converted into potential energy. At the end of surface 55, the fluid has attained its maximum pressure which acts on to a section of the dotted surface 51 and on to a considerably smaller section of surface 52.

Fig. 8a shows the forces acting onto the

partition walls

51 and 52 as well as onto the hub or exterior faces 53 to 55. The pressure area integral of surface 51 as to size and direction is represented by an arrow 61, and that of surface 52 by an arrow 62. The average pressure on surface 55 acts at right angles thereto. The resultant (as to size and direction) is represented by an arrow 65 and is projected, as 65', in direction of the axis of rotation AA onto the arrow 62. The composition of forces gives a resultant 66 which, for clarity, has been moved to the right in the drawing, as well as a resultant torque in direction of that partition wall which covers the larger area. That component of the torque vector which points in the axial direction must appear as having been produced by the compressor and in the form of absorbed output. In the turbine, the corresponding power is delivered.

In the case of supersonic flow, the conditions are fundamentally similar. In lieu of the gradual pressure rise in the diffusor, there appears here the compression shock as momentary pressure increase in parallel relation to the curve of intersection of the

surfaces

53 and 55. Rearwardly of said pressure surge are present the same dissymmetries of the pressure/area integrals which produce the torque as in the previously considered case of subsonic flow.

Figs. 9 to 13 show examples of longitudinal section curves such as are schematically illustrated in Fig. 3. Fig. 9 shows a hub surface 71, a partition wall 72 and an exterior surface 73 in the form of the casing surface. Fig. 10 shows the case where the exterior surface is formed by a shroud band 74. Fig. 11 shows a rotatory casing 78 with separation surfaces 76, whilst the hub surface 77 is stationary. Fig. 12 shows a duct subdivided by a partition wall 79, which duct may be employed, for example, in double-flow machines. Thereby are produced two superposed ducts K and K and partition wall 79 forms the exterior surface 79' for the interior duct K and the hub surface 79" for the exterior duct K In Fig. 13 is shown a cooling arrangement for ductforming surfaces. A coolant flows in at 81 and out at 82. In contrast to the difficulty of cooling arising in deflection blades on account of small dimensions, the hub surfaces and the exterior surfaces are readily coolable in the present case.

Fig. 14 is a developed view of two ducts having

partition walls

91 and 92, an inlet portion 93 in parallel re lation with one of the runner edges, and an edge 94 which is part of a hub surface 95.

Since, through boundary-layer removal by suction, diifusors, may be built which have substantially greater angles of aperture and cross-sectional ratios, a slot 96 serves for sucking oif the boundary layer on hub surface 95. Said slot communicates with a suction unit known per se. Similar slots may be employed for injecting a fluid into the ducts.

In contrast to the blade-like separation surfaces which act by deflection, hub surfaces and exterior faces may act through velocity energy variation.

The adaptation of duct-defining surfaces as new and essential element for turbines and the like in ducts of a turborunner according to the present invention, permits to provide energetically advantageous asymmetrical pressure distributions on partition walls without the latter having to participate therein directly, whereby energy may be taken from or supplied to the runner shaft. Among the various advantages of such an arrangement, the following may be mentioned. The diffuser effect of hub surfaces and exterior surfaces in axial compressors acts in radial direction. The hub ratio, i.e. the ratio of runner outside diameter to hub diameter is, however, small at higher pressures, which has a favorable influence on duct construction. No subdivision of the circumference according to effective depths is needed, as is necessary in known bladed runners. The partition walls, therefore, may have substantially greater spacing, which is of advantage as regards losses.

It may be mentioned yet in this connection, that in adaptation to the optimal conditions which, for example, result from a consideration of boundary-layer influences, spatial surfaces with curvilinear limits may be considered such as are shown, for example, in Fig. 1 or as formed by helical surfaces. 7

Another feature of the invention is the possibility of providing relatively thick partition walls without giving origin to excessive air resistance or secondary losses. Such arrangement is not possible in the case" of deflection blades on account of the operating range and the flow losses. Partition walls of this kind may be constructed as sturdy structural elements with high natural frequencies, in contradistinction to deflection blades.

The partition walls may be swept back at the entrance. Chamfered entrance edges prove of advantage for certain flow patterns, and such edges may be combined with the sweepback of the partition walls;

When great volumes are to be compressed at lower pressure ratios, it is of advantage-to form the side surfaces as airfoils so that they take part in the energy conversion in the compressor stage.- Such side surfaces, however, also may be used to still further increase the pressure ratio.

What I claim is:- V

1. In an apparatus of the type described, in combination, a rotor having a plurality of partitioning blades spaced about the periphery of said rotor, said rotor having peripheral surface sections located between adjacent partitioning blades, each of said surface sections including axially displaced surface areas of different diameter and a surface portion extending between and merging into each of said surface areas. each of said surface portions being inclined at an angle smaller than 90 to planes passing through the axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning, said ends of each surface portion being spaced from each other in axial direction of said rotor.

2. An apparatus of the type described comprising, in combination, a stator having an annular peripheral surface; and a rotor cooperating with said stator, said rotor having a plurality of partitioning blades spaced about the periphery thereof and extending toward said annular peripheral surface of said stator, said rotor having peripheral surface sections located between adjacent partitioning blades, each peripheral surface section defining toggether with a section of said peripheral surface of said stator and with the two associated partitioning blades a duct, each of said surface sections of said rotor including axially displaced surface areas of different diameter and a surface portion extending between and merging into said surface areas, so that the cross section of each of said ducts increases in one direction adapted to be the direction of flow of a fluid, each of said surface portions being inclined at an angle smaller than 90 with respect to" planes passing through said axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning, said ends of each surface portion being spaced from each other in axial direction of said rotor whereby greater pressure is exerted by the fluid on one of the two partitioning blade surfaces bounding each of said surface sections.

3. An apparatus as set forth in claim 2 wherein said partitioning blades at least partly have such shape as to act as deflection-type blades.

4. An apparatus as set forth in claim 3 in which said partitioning blades and all said surface sections are of identical shape and configuration, respectively, so that all said ducts are of identical configuration.

5. An apparatus as set forth in claim 2 wherein groups of said partitioning blades and groups of said surface sections are of identical shape and configuration respectively so that groups of identical configuration are formed.

6. An apparatus as set forth in claim 2 and including means for the additional injection of fluid into said ducts.

7. In an apparatus of the type described, in combination, a rotor having a plurality of outwardly projecting partitioning blades spaced about the outer periphery of said rotor, said rotor having outer peripheral surface sections located between adjacent partitioning blades, each of said surface sections including axially displaced surface areas of different diameter and a surface portion extending between and merging into said surface areas, each of said surface portions being inclined at an angle smaller than to planes passing through the axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning, said ends of each surface portion being spaced from each other in axial direction of said rotor.

8. An apparatus of the type described comprising, in combination, a stator having an inner annular peripheralsurface; and a rotor located within and cooperating with said stator, said rotor having a plurality of outwardly projecting partitioning blades spaced about the periphery thereof and extending toward said annular peripheral surface of said stator, said rotor having peripheral surface sections located between adjacent partitioning blades, each peripheral surface section defining together with a section of said peripheral surface of said stator and with the two associated partitioning blades a duct, each of said surface sections of said rotor including axially displaced surface areas of different diameter and a surface portion extending between and merging into said surface areas, so that the cross section of each of said ducts increases in one direction adapted to be the direction of flow of a fluid, each of said surface portions being inclined at an angle smaller than 90 with respect to planes passing through said axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning, said ends of each surface portion being spaced from each other in axial direction of said rotor whereby greater pressure is exerted by the fluid on one of the two partitioning blade surfaces bounding each of said surface sections.

9. An apparatus of the type described comprising, in combination, a stator having an inner annular peripheral surface; and a rotor surrounding said stator and cooperating with said stator, said rotor having a plurality of out wardly projecting partitioning blades spaced about the periphery thereof and extending toward said annular peripheral surface of said stator, said rotor having peripheral surface sections located between adjacent partitioning blades, each peripheral surface section defining together with a section of said peripheral surface of said stator and with the two associated partitioning blades a duct, each of said surface sections of said rotor including axially displaced surface areas of different diameter and a surface portion extending between and merging into said surface areas, so that the cross section of each of said ducts increases in one direction adapted to be the direction of flow of a fluid, each of said surface portions being inclined at an angle smaller than 90 with respect to planes passing through said axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning, said ends of each surface portion being spaced from each other in axial direction of said rotor whereby greater pressure is exerted by the fiuid on one of the two partitioning blades bounding each of said surface sections.

10. An apparatus of the type described comprising, in combination, a stator having an annular peripheral surface; and a rotor cooperating with said stator, said rotor having a plurality of partitioning blades spaced about the periphery thereof and extending toward said annular peripheral surface of said stator, said rotor having periperal surface sections located between adjacent partitioning blades, each peripheral surface section defining together with a section of said peripheral surface of said stator and with the two associated partitioning blades a duct, each of said surface sections of said rotor including a surface portion of gradually increasing diameter inclined at an angle smaller than 90 with respect to planes passing through said axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning blades, said ends of each surface portion being spaced from each other in axial direction whereby greater pressure is exerted by the fluid on one of the two partitioning blade surfaces bounding each of said surface sections.

11. In an apparatus of the type described, in combination, a stator means having an annular peripheral surface; a rotor means having an annular peripheral surface located opposite said first-mentioned annular surface, one of said annular peripheral surfaces being a hub surface and the other of said annular surfaces being an outer surface, said rotor means having a plurality of partitioning blades spaced about said annular peripheral surface thereof and extending toward said annular peripheral surface of said stator so that a plurality of ducts is formed between said partitioning blades and said annular peripheral surfaces, at least one ,of said peripheral annular surfaces having projecting surfaceportions, each of said surface portions having endslocated, respectively, at the as-- sociated partitioning blades, said ends of each surface portion being spaced from each other in axial direction so that said one annular surface is not a surface of revolution with respect to the axis of rotation of said rotor means.

12. An apparatus of the type described comprising, in combination, a stator having an annular peripheral surface; and a rotor cooperating with said stator, said rotor having a plurality of partitioning blades spaced about the periphery thereof and extending toward said annular peripheral surface of said stator, said rotor having peripheral surface sections located between adjacent partitioning blades, each peripheral surface section defining together with a section of said peripheral surface of said stator and with the two associated partitioning blades a duct, each of said surface sections of said rotor including a surface portion inclined at an angle smaller than with respect to planes passing through said axis of said rotor and intersecting the respective surface section, and with respect to planes perpendicular to the rotor axis, each of said surface portions having ends located, respectively, at the associated partitioning blades, said ends of each surface portion being spaced from each other in axial direction of said rotor whereby greater pressure is exerted by the fluid on one of the two partitioning blade surfaces bounding each of said surface sections.

References Cited in the tile of this patent UNITED STATES PATENTS 767,689 Hedlund Aug. 16, 1904 1,035,543 Dake Aug. 13, 1912 1,447,554 Jones Mar. 6, 1923 2,575,682 Price Nov. 21, 1951 2,648,492 Stalker Aug. 11, 1953 2,648,493 Stalker Aug. 11, 1953 2,657,902 Williams Nov. 3, 1953 2,675,208 Weinberg Apr. 13, 1954 2,732,999 Stalker Jan. 31, 1956 2,735,612 Hausmann Feb. 21, 1956 2,759,663 Stalker Aug. 21, 1956 FOREIGN PATENTS 386,039 Great Britain Jan. 12, 1933 833,532 France July 25, 1938 833,879 Germany Mar. 13, 1952.