Multi-stage radial compressor shutter

Abstract

The present invention relates to a multi-stage radial compressor shroud. An assembly can include a first radial compressor impeller having an axis of rotation and including a hub surface, a second radial compressor impeller including a hub surface, and an annular shroud disposed at least partially between the hub surfaces, wherein the annular shroud includes an outer edge and a substantially parabolic portion extending to a terminal portion, wherein the terminal portion includes opposing sides converging radially inwardly to a blunt end.

Description

Technical Field

[0001] The topics disclosed in this article generally relate to multi-stage radial compressors. Background Technology

[0002] Compressors are frequently used to increase the output of internal combustion engines. Turbochargers may include compressors, which can be multistage radial compressors. As an example, such a compressor may be driven by a turbine impeller operatively coupled to a shaft capable of rotatably driving the compressor, or, for example, such a compressor may be driven by another mechanism such as an electric motor. Various examples of techniques, sciences, etc., described herein relate to multistage radial compressors. Attached Figure Description

[0003] When considered in conjunction with the examples shown in the accompanying drawings, a more complete understanding can be gained by referring to the following detailed description, which includes the various methods, apparatuses, components, systems, arrangements, and equivalents described herein.

[0004] Figure 1 This is an example diagram of a turbocharger, internal combustion engine, and controller;

[0005] Figure 2 This is a cross-sectional view of an example turbocharger;

[0006] Figure 3 This is a cross-sectional view of an example component that includes a baffle.

[0007] Figure 4 It includes Figure 3 A cross-sectional view of a portion of the baffle assembly;

[0008] Figure 5 This is an example diagram showing the results of the Mach number of the flow in the path;

[0009] Figure 6 yes Figure 3 A plan view of an example baffle;

[0010] Figure 7 Is it like along Figure 6 The line AA shown in the plan view intercepts... Figure 6 A cross-sectional view of an example baffle;

[0011] Figure 8 yes Figure 3 An enlarged cross-sectional view of a portion of the baffle;

[0012] Figure 9 This is a cross-sectional view of an example component that includes a baffle.

[0013] Figure 10 This is a cross-sectional view of a portion of the component, illustrating the flow in a passage partially defined by a baffle; and

[0014] Figure 11 This is an example of a table that includes information about the two baffles. Detailed Implementation

[0015] Turbochargers are frequently used to increase the output of internal combustion engines. (Reference) Figure 1 As an example, system 100 may include an internal combustion engine 110 and a turbocharger 120. Figure 1 As shown, system 100 may be part of vehicle 101, wherein system 100 is disposed in the engine compartment and connected to exhaust duct 103, which directs exhaust gas to exhaust outlet 109, for example, located behind passenger compartment 105. Figure 1 In the example, the processing unit 107 may be configured to process exhaust gas (e.g., to reduce emissions through catalytic conversion of molecules, etc.).

[0016] like Figure 1 As shown, the internal combustion engine 110 includes: an engine block 118 that houses one or more combustion chambers that operatively drive a shaft 112 (e.g., via a piston); and an intake port 114 that provides a flow path for air to the engine block 118 and an exhaust port 116 that provides a flow path for exhaust from the engine block 118.

[0017] The turbocharger 120 can be used to extract energy from exhaust gas and provide energy to incoming air, which can combine with fuel to form combustion gases. For example... Figure 1 As shown, the turbocharger 120 includes an air inlet 134, a shaft 122, a compressor housing assembly 124 for a compressor impeller 125, a turbine housing assembly 126 for a turbine impeller 127, another housing assembly 128, and an exhaust outlet 136. The housing assembly 128 may be referred to as the central housing assembly because it is disposed between the compressor housing assembly 124 and the turbine housing assembly 126. The shaft 122 may be a shaft assembly comprising multiple components. The shaft 122 may be rotatably supported by a bearing system (e.g., journal bearings, rolling element bearings, etc.) disposed in the housing assembly 128 (e.g., in a bore defined by one or more bore walls), such that rotation of the turbine impeller 127 causes (e.g., as rotatably coupled by the shaft 122) rotation of the compressor impeller 125. As an example, the central housing rotating assembly (CHRA) may include a compressor impeller 125, a turbine impeller 127, a shaft 122, a housing assembly 128, and various other components (e.g., a compressor side plate disposed at an axial position between the compressor impeller 125 and the housing assembly 128).

[0018] exist Figure 1 In the example, variable geometry component 129 is shown partially disposed between housing assembly 128 and housing assembly 126. Such a variable geometry component may include blades or other components to change the geometry of the passageway leading to the turbine impeller space in the turbine housing assembly 126. As an example, a variable geometry compressor assembly may be provided.

[0019] exist Figure 1 In the example, the exhaust valve (or simply exhaust valve) 135 is positioned near the exhaust inlet of the turbine housing assembly 126. The exhaust valve 135 is controllable to allow at least some exhaust gas from the exhaust port 116 to bypass the turbine impeller 127. Various exhaust valves, exhaust valve components, etc., can be applied to conventional fixed-nozzle turbines, fixed-blade nozzle turbines, variable-nozzle turbines, twin-scroll turbochargers, etc. As an example, the exhaust valve can be an internal exhaust valve (e.g., at least partially inside the turbine housing). As an example, the exhaust valve can be an external exhaust valve (e.g., operatively coupled to a duct in fluid communication with the turbine housing).

[0020] exist Figure 1 The example also shows an exhaust gas recirculation (EGR) duct 115, which may optionally be provided with, for example, one or more valves 117 to allow exhaust gas to flow to a location upstream of the compressor impeller 125.

[0021] Figure 1 Exemplary arrangement 150 for directing exhaust gas flow to exhaust turbine housing assembly 152 and another exemplary arrangement 170 for directing exhaust gas flow to exhaust turbine housing assembly 172 are also shown. In arrangement 150, cylinder head 154 includes internal passages 156 to guide exhaust gas from cylinders to turbine housing assembly 152, while in arrangement 170, manifold 176 provides mounting of turbine housing assembly 172, for example, without any separate intermediate length exhaust pipe. In exemplary arrangements 150 and 170, turbine housing assemblies 152 and 172 can be configured for use with wastegates, variable geometry components, etc.

[0022] exist Figure 1In this document, an example of controller 190 is shown including one or more processors 192, memory 194, and one or more interfaces 196. Such a controller may include circuitry, such as that of an engine control unit (ECU). As described herein, various methods or techniques may be optionally combined with the controller, for example, through control logic. The control logic may depend on one or more engine operating states (e.g., turbo rpm, engine rpm, temperature, load, lubricant, cooling, etc.). For example, sensors may transmit information to controller 190 via the one or more interfaces 196. The control logic may depend on such information, and controller 190 may output control signals to control engine operation. Controller 190 may be configured to control lubricant flow, temperature, variable geometry components (e.g., variable geometry compressors or turbines), exhaust valves (e.g., via actuators), electric motors, or one or more other components associated with the engine, turbocharger (or multiple turbochargers), etc. As an example, turbocharger 120 may include one or more actuators and / or one or more sensors 198, which may be coupled to one or more interfaces 196 of controller 190, for example. As an example, the exhaust valve 135 may be controlled by a controller that includes an actuator responsive to an electrical signal, a pressure signal, etc. As an example, the actuator for the exhaust valve may be a mechanical actuator, for example, one that can operate without electricity (e.g., consider a mechanical actuator configured to respond to a pressure signal provided via a conduit).

[0023] Figure 2 An example of a turbocharger assembly 200 is shown, comprising a bearing housing 210 that supports a bearing assembly 230 within a through-hole in the bearing housing 210. The bearing assembly 230 may be or include a rolling element bearing assembly. For example, the bearing assembly 230 may be a bearing cartridge comprising an inner ring 232 and an outer ring 234, wherein rolling elements are disposed between the inner and outer rings 232, and wherein a shaft 220 is operatively coupled to the inner ring 232 such that rotation of the shaft 220 causes rotation of the inner ring 232. In such an example, the outer ring 234 may be positioned relative to the bearing housing 210 (e.g., via a positioning mechanism, etc.). As an example, a sealing element may be provided about the shaft 220 (e.g., or a collar), for example, to reduce the flow of air and / or exhaust gas to the bearing assembly 230. Such a sealing element may also be used to reduce the flow of lubricant (e.g., in the opposite direction).

[0024] exist Figure 2In the example, turbocharger assembly 200 includes compressor assembly 240, which includes inlet 241 that may be formed as part of a first compressor housing member 242-1, which may be operatively coupled to a second compressor housing member 242-2. As shown, the first compressor housing member 242-1 may at least partially define a first volute 243-1, and the second compressor housing member 242-2 may at least partially define a second volute 243-2. Figure 2 In the example, the first compressor impeller 244-1 directs gas (e.g., air, an air-exhaust mixture, etc.) to the first diffuser section 245-1 to the first volute 243-1, and the second compressor impeller directs air to the second diffuser section 245-2 to the second volute 243-2. ​​For example, compressor impellers 244-1 and 244-2 may each include a corresponding inlet section and a corresponding outlet section, wherein gas flows into the inlet section and exits from the outlet section (e.g., to the corresponding diffuser section). Figure 2 As shown in the example, compressor impellers 244-1 and 244-2 are radial compressor impellers. As an example, a radial compressor can achieve a pressure increase by adding kinetic energy (e.g., velocity) to a fluid flow (e.g., air, etc.) passing through a rotor (e.g., impeller or "wheel"). As an example, this kinetic energy can be converted into an increase in potential energy (e.g., static pressure), for example, by slowing the flow through the diffuser section.

[0025] exist Figure 2 In the example, turbocharger assembly 200 includes turbine assembly 260, which includes turbine housing part 262, insert part 263, and turbine impeller 264. As an example, turbine assembly 260 may include a nozzle adjustment mechanism, such as a variable geometry mechanism, that adjusts the position of the impeller blades, etc., to define a throat for directing exhaust gas to turbine impeller 264. As an example, turbine impeller 264 may be operatively coupled to shaft 220. As an example, turbine impeller 264 and the shaft may be a shaft and impeller assembly (SWA). Figure 2 In the example, exhaust gas can flow to turbine impeller 264, causing turbine impeller 264 to rotate and thereby causing shaft 220 to rotate. Figure 2In the example, the first compressor impeller 244-1 and the second compressor impeller 244-2 are operatively coupled to the shaft 220 (e.g., by positioning the shaft 220 in through-holes in the compressor impellers 244-1 and 244-2 and fitting a nut or other mechanism at the nose of the compressor impeller 244-1, through a partially perforated or "perforated" double-sided compressor impeller assembly, etc.). Therefore, energy can be extracted from the exhaust gas to cause rotation of the shaft 220 and rotation of the first compressor impeller 244-1 and the second compressor impeller 244-2. In such an example, gas flowing into the compressor assembly 240 (e.g., air, an air-exhaust mixture, etc.) can be compressed and exit the compressor assembly 240 at an outlet 249, which may, for example, be part of the second compressor housing component 242-2.

[0026] Although Figure 2 The example shows turbine assembly 260 as a mechanism of rotatable compressor impellers 244-1 and 244-2, but for example... Figure 2 The compressor impellers of the compressor assembly 240 may be additionally or alternatively driven by different types of mechanisms. For example, an electric motor may be operatively coupled to a shaft to which the first compressor impeller 244-1 and the second compressor impeller 244-2 are operatively coupled. In such an example, electrical power may be supplied to the electric motor to rotatably drive the shaft, and thus drive the compressor impellers 244-1 and 244-2. In such an example, a bearing housing may be optionally implemented as part of the electric motor assembly (e.g., consider a motor housing housing a stator and rotor coupled to the shaft, wherein the rotor is included in the motor housing to rotatably support the shaft).

[0027] exist Figure 2 In one example, a baffle 280 is present, comprising an outer surface 281, a portion of which partially defines a first diffuser section 245-1, and another portion of which partially defines a second diffuser section 245-2. As an example, the first compressor impeller 244-1, the first diffuser section 245-1, and the first volute 243-1 can operate at a lower pressure than the second compressor impeller 244-2, the second diffuser section 245-2, and the second volute 243-2. ​​In such an example, a gas (e.g., air, an air-exhaust mixture, etc.) can flow into the compressor assembly 240 via inlet 241, be compressed by the first compressor impeller 244-1, and subsequently flow to the second compressor impeller 244-2, where it is further compressed and directed to outlet 249. In such an example, the compressor assembly 240 may be referred to as a two-stage compressor assembly having a first low-pressure stage and a second high-pressure stage.

[0028] In this two-stage arrangement, during operation, the gas pressure in the first diffuser section 245-1 is expected to be lower than the gas pressure in the second diffuser section 245-2. In this example, gas can flow from the second diffuser section 245-2 to the first diffuser section 245-1. Such flow may reduce the operating efficiency of the compressor assembly 240. As another example, such flow can increase the temperature of the gas flowing in the first diffuser section 245-1, which in turn increases the temperature of the gas flowing to the inlet section of the second compressor impeller 244-2, thereby reducing the overall effectiveness of the second stage.

[0029] In a compressor assembly such as compressor assembly 240, it is desirable to isolate the operation of the first compressor impeller 244-1 when gas flows from the inlet section to the outlet section and enters the first diffuser section 245-1, and to isolate the operation of the second compressor impeller 244-2 when gas flows from the inlet section to the outlet section and enters the second diffuser section 245-2. However, baffle 280 may define a slightly annular V-shaped passage relative to the hub portions of compressor impellers 244-1 and 244-2, in which gas can flow from a higher pressure region to a lower pressure region. Specifically, during the operation of the two-stage compressor assembly, gas can flow from the region of the high-pressure stage to the region of the low-pressure stage via such a passage. For example, consider a portion of the gas compressed by the second compressor impeller 244-2 flowing to a region adjacent to the hub portion of the first compressor impeller 244-1. In such an example, this portion of gas does not directly enter the second diffuser section 245-2. This phenomenon can be referred to as "interstage leakage". As an example, interstage leakage can reduce overall compressor stage efficiency.

[0030] As an example, the outer surface 281 of the baffle 280 may include one or more shapes for reducing interstage leakage. As an example, the hub portion of at least one of the compressor impellers 244-1 and 244-2 may include one or more shapes for reducing interstage leakage. As an example, the baffle and one or more hub portions may include shapes for reducing interstage leakage.

[0031] Figure 3 An example of a portion of a compressor assembly 300 is shown, including a first compressor impeller 344-1, a second compressor impeller 344-2, and a baffle 380, which is at least partially disposed between the hub portion of the first compressor impeller 344-1 and the hub portion of the second compressor impeller 344-2. Figure 3 In the example, the second compressor impeller 344-2 can be considered as the high-pressure stage compressor impeller, while the first compressor impeller 344-1 can be considered as the low-pressure stage compressor impeller.

[0032] like Figure 3 As shown in the example, a passage is defined, which may be defined by impellers 344-1 and 344-2 and baffle 380. As shown, impellers 344-1 and 344-2 may include different base diameters to allow for offset. For example, impeller 344-2 may include a smaller base diameter than impeller 344-1, such that the annulus is formed with a cross-section that can be approximated as triangular.

[0033] like Figure 3 As shown in the example, baffle 380 may include opposing sides, each side being shaped in a complementary manner relative to a corresponding impeller shape. For example, the low-pressure side of baffle 380 has a shape on at least a portion of this low-pressure side that is complementary to the shape of the backdisk portion of the low-pressure impeller 344-1, and the high-pressure side of baffle 380 has a shape on at least a portion of this high-pressure side that is complementary to the shape of the backdisk portion of the high-pressure impeller 344-2. Figure 3 In the example, the back plate portions of impellers 344-1 and 344-2 are generally concave, while the opposite sides of baffle 380 are generally convex. As explained below, the end portion 381 of baffle 380 may be suitably shaped, wherein, for example, variations in concavity may exist on one or both sides of baffle 380 at or near the end portion 381.

[0034] Changes in concavity can be indicated by inflection points. An inflection point is a point on a curve where the sign of its curvature (i.e., concavity) changes. An inflection point may be a stationary point, rather than a local maximum or minimum. For example, for the curve y=x... 3 The point x=0 is an inflection point. A necessary condition for the point x to be an inflection point is that the second derivative of the function with respect to x is equal to zero at the point x. As an example, the baffle may have opposite sides, where one or both of the opposite sides have inflection points, which may be located in the transition region between the curved portion and the end portion (e.g., before the end endpoint, etc.).

[0035] As an example, the baffle may be defined using one or more mathematical terms. As an example, at least a portion of the baffle profile may be defined using a parametric curve. The parametric curve may be defined in part by continuity in terms of differentiability. For example, C 0 Continuity means that curves connect at the junctions, C 1 Continuity means that curves are connected as segments that share a common first derivative at the junction, and C n Continuity means that segments share the same nth derivative at the junction. As an example, the baffle profile can be formed by having C 0 Continuity and / or greater than C0 It is represented by a continuous parametric curve. For example, C 0 Continuity may exist at the transition between the generally parabolic portion and the end portion of the baffle. The transition region may include a transition point where two segments intersect and which may define the continuity (e.g., for at least C). 0 (Continuity) junction.

[0036] As an example, the baffle profile can be represented by one or more parametric polynomial curves. As an example, one or more splines can be used to define the baffle profile and / or one or more blending functions can be used to define it. Regarding splines, some examples include Hermite, Bezier, Catmull-Rom, and B-Spline. As an example, the baffle profile can be represented using control points that can be used for joints. For example, the baffle profile can be represented using control points in the r,z plane to define several segments, where these segments can have at least C at the control points (e.g., joints). 0 Continuity. In such an example, one or more splines may be used to define the baffle profile. As an example, one or more splines, one or more types of continuity, etc., may be used to define the impeller back disk profile. As explained, the baffle may include at least a portion of the profile that is complementary to at least a portion of the impeller back disk profile.

[0037] As shown, the gap can be defined as, for example, a low-pressure side passage gap and a high-pressure side passage gap. Figure 3 The example shows two different temperatures T. Low and T High The gaps “a” and “b” below, where T Low It can be the ambient temperature, and T High This can be the operating temperature. As shown, at T... Low Below, a > b, and in T High Below, a ~ b. Such differences may be due to the thermal environment and the thermal expansion and contraction of components. For example, the baffle may be shaped such that, taking into account the thermal characteristics of the components, the spatial relationship between the baffle and the back-to-back impellers is suitable over a certain temperature range, wherein this spatial relationship is at or near optimal over a certain operating temperature range (e.g., above ambient temperature). The operating temperature of the compressor assembly may exceed approximately 50 degrees Celsius and may depend on the exhaust temperature, cooling and / or lubricating fluids, ambient air temperature, etc. Figure 3As shown in the example, as the temperature rises from ambient temperature to operating temperature, the baffle 380 may become more centered relative to impellers 344-1 and 344-2 (e.g., centered relative to the interface defined by the two impellers 344-1 and 344-2). For example, at ambient temperature, the baffle 380 may be offset toward the high-pressure impeller 344-2 and more centered at higher temperatures. Figure 3 In the example, because the high-pressure impeller 344-2 has a smaller maximum diameter (e.g., outer diameter or circumference), the end portion 381 is offset toward the high-pressure impeller 344-2.

[0038] like Figure 3 As shown in the example, baffle 380 may include an end portion 381 that defines an annular portion of baffle 380, wherein the end portion 381 may be partially defined as an annular portion having a cross-section that can be approximated as a truncated triangle. For example, consider a triangle having a base defined between two vertices and lateral sides extending from the vertices to the truncated point, such that a third vertex of the triangle does not exist. As an example, such a truncated triangle shape may be defined by two interior angles, such as those defined between the base and each lateral side. In such an example, the lateral sides are not parallel but antiparallel, such that they converge. In such an example, the interior angles may be the same or they may be different.

[0039] As an example, the truncated triangle shape can be either a quadrilateral or a rectangular shape. For example, consider a quadrilateral having a base that is radially distanced from the axes of rotation of the two compressor impellers, and opposing sides that converge to an end that is radially distanced from the axes of rotation of the two compressor impellers. As an example, the quadrilateral can be convex; for example, consider a convex hull. As an example, the quadrilateral can be a trapezoid, where the base and the end can be parallel or non-parallel, and the opposing sides converge from the base to the end.

[0040] exist Figure 3 In the example, the end portion 381 is shown as being defined in cross-section by quadrilaterals with at least some different interior angles. In such an example, two interior angles may be approximately the same. For example, the interior angle between the side and the end may be approximately the same and greater than approximately 90 degrees. Figure 3 In the example, the end portion 381 is shown to include an interior angle less than 90 degrees, corresponding to the interior angle between the longer side and the bottom edge of the opposing sides. In such an example, another interior angle between the shorter side and the bottom edge of the opposing sides is greater than 90 degrees.

[0041] exist Figure 3In the example, the end portion 381 of the baffle 380 may extend radially outward from the curved portion 383. For example, consider a curved portion that may be defined by one or more curves, which may be defined by one or more types of equations. For example, consider a parabolic equation such that the baffle 380 includes one or more parabolic shapes (e.g., complementary to one or more shapes of one or more backplate portions, etc.).

[0042] As an example, the baffle may include a transition region between a curved portion and an end portion. For example, baffle 380 may include a transition region between a curved portion 383 and an end portion 381, which may be defined using one or more types of curves. As an example, a machining process may be used to form baffle 380 or a portion thereof. For example, consider machining the end portion 381 and the transition region between the end portion 381 and the curved portion 383, where the transition region may be designed to reduce stress, reduce flow disturbance, etc. For example, the transition region may be aerodynamically shaped to make the transition from the curved portion 383 to the end portion 381 smooth.

[0043] As an example, an annular baffle for a two-stage radial compressor assembly may include an outer edge (e.g., an outer end); and a generally parabolic portion including an inner edge defining an opening having a central axis, and opposing surfaces extending from the inner edge. In such an example, the opposing surfaces may converge from the parabolic portion (e.g., a curved portion) to an end portion, which may include a blunt end. As mentioned, in cross-section, the blunt end may be defined using a truncated triangle, quadrilateral, etc.

[0044] As an example, the end portion may include an end shaped to facilitate vortex formation (e.g., see [link]). Figure 5 Such vortices can provide flow at elevated Mach numbers. The Mach number is a dimensionless quantity in fluid dynamics, representing the ratio of the flow velocity through a boundary to the local sound velocity. Such vortices (e.g., eddies) can be deflected toward the low-pressure side, with the flow directed from the high-pressure side to the low-pressure side. Such vortices can help reduce the flow from the high-pressure side to the low-pressure side. In 3D, such vortices can be annular and / or can be several individual vortices arranged in a substantially annular manner. Figure 3As shown in the example, the end portion 381 may include an end having a flat profile extending from one corner to the other. As an example, the end may be curved, for example, consider a slight bend (e.g., see the dashed line), which may be between two corners (e.g., sharp and / or rounded). For a slight curve, it may be defined by a circle, where the diameter of the circle is equal to or less than the distance between corners (e.g., equal to or less than a hemisphere). As an example, a sharp corner on the downstream side (e.g., the low-pressure side) may help promote vortex formation. As an example, a slight smoothing of the diagonals may reduce the risk of cutting or other damage upon contact. As an example, the end portion may be shaped to promote vortex formation with an elevated Mach number, which may be the maximum Mach number in the gap formed between the back disk portion of the compressor impeller and the annular baffle.

[0045] As an example, the end portion can be a vortex-forming feature of an annular baffle. As an example, the end portion can act as a flow barrier within the flow field, where one or more vortices are formed by the flow passing through it. The article by Teimourian et al., entitled “Vortex Shedding Suppression: A Review on Modified Bluff Bodies” (Eng2021, 2, 325-339, 27 July 2021), is incorporated herein by reference. This article by Teimourian et al. relates to vortex shedding suppression through geometric modification of the flow barrier. Figure 3 In the example, baffle 380, particularly end portion 381, can be a flow-blocking material with a geometry that can intentionally promote vortex formation.

[0046] Vortex formation can depend on a variety of conditions. The local sound velocity, and therefore the Mach number, depends on the temperature of the surrounding gas. The Mach number can be used to determine whether a flow can be considered incompressible or compressible. The boundary along which the gas flows can be fixed (e.g., static). The boundary can be the boundary of an object submerged in the gas, or it can be the boundary of a channel guiding the gas (e.g., a baffle). Since the Mach number is defined as the ratio of two velocities, it is a dimensionless number. If the Mach number is less than 0.2–0.3 and the flow is quasi-steady and isothermal, the compressibility effect may be small, and a simplified incompressible flow equation can be used. As an example, in compressor operation, the Mach number may exceed 1.0. For example, in… Figure 5 In this context, eddies can form with Mach numbers greater than 1.0 (e.g., depending on conditions, etc.). In such examples, one or more other regions may have flows with Mach numbers less than 1.0 (e.g., depending on conditions, etc.).

[0047] exist Figure 3In the example, baffle 380 provides a reduced distance between the compressor backplate portion and the chocking area, which may be partially defined by the end portion 381 and partially by the compressor backplate portion. In such an example, reducing the chocking area itself can help reduce leakage flow from the high-pressure side to the low-pressure side. In the event of undesirable extreme shaft movement, there is a risk of contact with baffle 380 due to the compressor impellers 344-1 and 344-2 being mounted to the shaft. However, given the shape of baffle 380, it is likely that only a relatively small surface area will come into contact, and due to the very small radius (e.g., near where the compressor impellers meet), any material that might wear down the compressor impellers 344-1 and / or 344-2 will have a relatively small impact on impeller balance.

[0048] Figure 4 A cross-sectional view of a portion of component 400 is shown, including a compressor assembly 440 operatively coupled to a central housing component 450. The central housing includes a bearing assembly 430 rotatably supporting a shaft 420, with a nut 422 axially positioning a first compressor impeller 444-1 and a second compressor impeller 444-2 relative to a collar 470. As shown, a baffle 380 is partially disposed in the space defined by the hub surfaces of the first compressor impeller 444-1 and the second compressor impeller 444-2, and also partially disposed between the first compressor housing component 442-1 and the second compressor housing component 442-2.

[0049] exist Figure 4 In the example, the surface of baffle 380 forms a diffuser section 445-1 with the surface of the first compressor housing component 442-1, wherein the diffuser section 445-1 is in fluid communication with the volute 443-1, and the other surface of baffle 380 forms a diffuser section 445-2 with the surface of the second compressor housing component 442-2, wherein the diffuser section 445-2 is in fluid communication with the volute 443-2. ​​As an example, the first and second compressor housing components 442-1 and 442-2 can be operatively coupled (e.g., clamped, etc.) to position baffle 380 (e.g., radially and / or axially, for example, to hold baffle 380 in a fixed manner relative to housing components 442-1 and 442-2).

[0050] exist Figure 4In the example, from a lower axial position to a higher axial position, assembly 400 includes an inner ring of bearing assembly 430 that contacts an axial face of collar 470 that contacts an axial end face of a second compressor impeller 444-2. As shown, the axial face at the hub end of the second compressor impeller 444-2 contacts the axial face at the hub end of the first compressor impeller 444-1, wherein a nut 422 (e.g., or other component) can be received by shaft 420 to axially position compressor impellers 444-1 and 444-2 on shaft 420. For example, nut 422 can be tightened (e.g., to meet torque specifications) to apply compressive force to the first and second compressor impellers 444-1 and 444-2 (e.g., relative to collar 470, etc.).

[0051] exist Figure 4 In the example, shaft 420 can be rotatably driven (e.g., by a turbine, electric motor, etc.) so that, for example, air flows into compressor assembly 440 through opening 441-1. Figure 4 In the example, opening 441-1 may be partially defined by compressor housing inlet component 492, which may form part of a recirculation passage (e.g., together with the first compressor housing component 442-1).

[0052] exist Figure 4 In the example, compressor assembly 440 includes two stages: a first stage (e.g., a low-pressure stage) formed by a first compressor impeller 444-1, a first compressor housing component 442-1, and a baffle 380; and a second stage (e.g., a high-pressure stage) formed by a second compressor impeller 444-2, a second compressor housing component 442-2, and a baffle 380. The direction of fluid flow is indicated by an arrow with an empty head, wherein the fluid (e.g., air or air and exhaust) flows axially inward to the inlet portion of the first compressor impeller 444-1 and radially outward from the outlet portion of the first compressor impeller 444-1 to the diffuser section 445-1. The fluid in the diffuser section 445-1 then flows to the volute 443-1 and continues to the inlet 441-2 of the inlet portion of the second compressor impeller 444-2. As shown, fluid flows from the inlet portion of the second compressor impeller 444-2 to the outlet portion of the second compressor impeller 444-2, and then flows to the diffuser section 445-2. The fluid in the diffuser section 445-2 then flows to the volute 443-2 and continues to flow to a duct that is in fluid communication with the intake port (e.g., intake manifold) of the internal combustion engine.

[0053] Describable and, for example, limited with respect to cylindrical coordinates Figure 4Various features of component 400. For example, consider the r, z, and Θ coordinate system, where z is along the axis of rotation of axis 420, which may coincide with the axes of the first and second compressor housing components 442-1 and 442-2.

[0054] As an example, the efficiency of compressor assembly 440 may depend on its ability to impede unwanted fluid flow from the second stage to the first stage. Figure 4 In the example, the shape of the baffle 380 and, for example, the hub surface of one or both of the compressor impellers 444-1 and 444-2 can serve to impede unwanted fluid flow from the second stage to the first stage.

[0055] Figure 5 A plot 500 shows the results of a computational fluid dynamics (CFD) model of a baffle 380 positioned relative to impellers 344-1 and 344-2, indicating the high-pressure and low-pressure sides. The contour lines in plot 500 are indicated in the legend from low Mach number to high Mach number. Again, in such an example, impellers 344-1 and 344-2 rotate at considerably high speeds (e.g., exceeding 100,000 rpm). As explained, the Mach number (M or Ma) is a dimensionless quantity in fluid dynamics, representing the ratio of the flow velocity across the boundary to the local sound velocity. As shown, the highest Mach number occurs on the low-pressure side, near the end portion 381 of baffle 380 and close to impeller 344-1. Figure 5 In the example, the Mach number is in the range of approximately 0 to greater than 1 but less than 2.

[0056] exist Figure 5 In the example, due to the arrangement of the features, the Mach 1 region is located on the low-pressure (LP) side. As an example, the arrangement of the features may be designed to provide an optimized diffuser shape (e.g., profile) to achieve Mach 1 closest to the impeller axis, with the smallest area located there to achieve minimal leakage flow at the choke. As an example, the component may include geometric features arranged, for specific stacking and tolerance conditions, as close as possible to the axis of the shaft (e.g., to minimize leakage area / mass flow) to create aerodynamic flow blockage (e.g., blockage region).

[0057] Figure 6 An example of baffle 380 and a plan view of line AA are shown, and a cross-sectional view of line AA is shown in... Figure 7 As shown in [the image]. Figure 6 In the plan view, the end portion can be considered to be located at the minimum radius or minimum diameter of the baffle 380, thus forming the inner perimeter of the baffle 380. The outer perimeter of the baffle 380 can be defined at the maximum radius or maximum diameter.

[0058] Figure 7 It shows along Figure 6 A cross-sectional view of baffle 380 along the centerline indicated by line AA. As an example, baffle 380 may be positioned relative to one impeller, and subsequently, another impeller may be positioned such that baffle 380 is disposed between the two impellers. Alternatively, the baffle may be a multi-piece baffle that can be installed after the two impellers are placed together, or, for example, a double-sided impeller in which the two impellers are formed as a single piece from a common material.

[0059] Figure 7 Various dimensions are shown, including the innermost radius R1 (e.g., at the inner end, which may be a blunt end), the radius R2 at one end of the curved portion (e.g., a substantially parabolic portion), the radius R3 at the other end of the curved portion (e.g., a substantially parabolic portion), the radius R4 at one end of the substantially flat portion (e.g., a diffuser portion), the radius R5 at the other end of the substantially flat portion (e.g., a diffuser portion), and the outermost radius R6 (e.g., at the outer edge or outer end). As shown, various axial thicknesses can be defined, such as the axial thickness DZ1 (e.g., the axial thickness of the substantially parallel portion of the baffle 380 relative to the parabolic profile) and the axial thickness DZ2 (e.g., the axial thickness of the diffuser-to-diffuser portion of the baffle 380). Figure 7 As shown in the example, the low-pressure side diffuser surface may extend between radii R3 and R5, and the high-pressure side diffuser surface may extend between radii R2 and R4. As indicated by radii R2 and R3, the maximum diameter of the high-pressure compressor impeller (e.g., see R3) may be smaller than the maximum diameter of the low-pressure compressor impeller (e.g., see R2).

[0060] Figure 8 A cross-sectional view of an example of a baffle 380 including an end portion 381 is shown. As shown, the baffle 380 can be defined using various parameters, dimensions, angles, etc. (see, for example, [link to relevant documentation]). Figure 3 The end portion 381). In Figure 8 The example shows the angle ϕ L and ϕ H It can be measured relative to the axis of rotation or a line parallel to it. Figure 8 In the example, the angle can range from approximately 40 degrees to 85 degrees. As an example, consider a range with a lower limit of approximately 50 degrees and an upper limit of approximately 85 degrees. Figure 8 In the example, the angle is approximately 75 degrees.

[0061] like Figure 8 As shown in the example, the low-pressure side can be composed of a radius r L Limited, and the high-pressure side can be determined by radius r H The definition, wherein, for example, as measured from the axis of rotation which may be one or more impellers, r HCan be greater than r L .

[0062] exist Figure 8 In the example, the end portion 831 may be defined by an axial span Δz. As shown, the end portion 831 may include a blunt end. As explained, the baffle 380 may be fixed when both impellers rotate, such that pressure can drive the flow of air from the high-pressure side to the low-pressure side (e.g., air and exhaust).

[0063] Figure 9 An example of a portion of a compressor assembly 900 is shown, including a first compressor impeller 944-1, a second compressor impeller 944-2, and a baffle 980, which is at least partially disposed between the hub portion of the first compressor impeller 944-1 and the hub portion of the second compressor impeller 944-2. Figure 9 In the example, the second compressor impeller 944-2 can be considered as the high-pressure stage compressor impeller, while the first compressor impeller 944-1 can be considered as the low-pressure stage compressor impeller.

[0064] exist Figure 9 In the example, the hub portions of impellers 944-1 and 944-2 have a common outer radius, allowing them to meet without offset. As shown, the profiles (e.g., shapes) of the backplate portions of impellers 944-1 and 944-2 may differ, with baffle 980 having complementary profiles (e.g., shapes). In such an example, gaps a and b may be within plus or minus 20% of each other, wherein, for example, these gaps may become more equal over a range of operating temperatures. As an example, in the case where the hub portions of the two impellers are approximately equal (e.g., plus or minus 10% or less) and made of a common material (e.g., the same alloy, etc.), a baffle may be constructed in which gaps a and b remain approximately equal (e.g., plus or minus 10% or less) over a temperature range that includes both ambient and operating temperatures.

[0065] like Figure 9 As shown in the example, baffle 980 may include some asymmetry, as mentioned, which may be due to the asymmetry between the two impellers positioned back-to-back to form the low-pressure and high-pressure stages of a multi-stage compressor assembly. The baffle may include one or more profile shapes, which may be defined by one or more of straight lines, curves, angles, etc.

[0066] like Figure 9As shown, an annular baffle 980 can be used in a two-stage radial compressor assembly, wherein the annular baffle may include an outer edge (e.g., an outer end); and a generally parabolic portion 983 extending to an end portion 981, wherein the end portion 981 includes opposite sides converging radially inward to a blunt end. As shown, the blunt end may be defined by a relatively flat surface, which may be an annular surface defining the inner perimeter of the annular baffle. As explained, the blunt end may be slightly curved between corners (e.g., sharp and / or rounded) (e.g., see dashed lines).

[0067] As explained, the end portion of the baffle may be partially defined by a low-pressure side transition region and a high-pressure side transition region, where a change in curvature may occur, for example, a change from a curved surface (e.g., a curved portion that may be substantially parabolic) to a less curved surface that may be a straight surface (e.g., a flat surface). As explained, the end portion may include opposing surfaces converging to a blunt end.

[0068] Regarding the blunt end, the wedge can be considered as a tool that functions by converting the force applied to its blunt end into a force perpendicular (e.g., normal) to its inclined surfaces, which meet at the sharp end or apex. As explained, the end portion of the annular baffle may include an extension to the opposite side of the blunt end, wherein the opposite side may converge to the blunt end at an angle of 90 degrees or less (e.g., less than 91 degrees) and greater than approximately 50 degrees.

[0069] Figure 10 An example of approximate streamlines of fluid in a passage at least partially formed by different baffles is shown, baffle 1080 being part of an example of an assembly 1000 including compressor impeller 1050 and compressor impeller 1070. As shown in the exemplary assembly 1000, compressor impeller 1050 includes a hub portion having a surface 1051 including a first annular tip 1053, a second annular tip 1055, an annular corner 1057, and an annular face 1059, and compressor impeller 1070 includes a hub portion having surface 1071. As shown, baffle 1080 includes a side 1081 extending to an end 1089, wherein opposing sides include annular channels 1083 and 1085 and an annular notch 1087.

[0070] As an example, an annular tip can be a feature formed by two intersecting annular curved surfaces. As an example, an annular tip can include a maximum defined by an annular line or, for example, an annular surface. As an example, the hub surface of a compressor impeller can include features extending outwards away from the hub surface, where such features can be, for example, a tip in cross-section. As an example, a feature on the hub surface of a compressor impeller can be a ridge. As an example, an annular tip can be a ridge. As an example, a ridge can be partially formed by one or more curved surfaces.

[0071] like Figure 10 As shown, for a given overall flow direction (see large arrows), annular vortices are formed, which may include one or more clockwise rotating vortices and one or more counterclockwise rotating vortices. For example, three clockwise (CW) rotating vortices are shown, and two counterclockwise (CCW) rotating vortices are shown.

[0072] exist Figure 10 In the example, streamlines and vortices are approximations because the flow between the fixed surface (e.g., baffle 1080) and the rotating surface (e.g., compressor impellers 1050 and 1070) can form a Couette-type flow that may exist between parallel plates, one of which moves relative to the other. Furthermore, given that the rotational speeds of the compressor impellers 1050 and 1070 can be approximately tens of thousands of revolutions per minute (rpm) and up to 100,000 rpm or higher, such a flow can be turbulent. Therefore, the flow can be complex and includes pressure-driven flow (e.g., as a driving force from a high-pressure region to a low-pressure region) and Couette-type flow, which may be turbulent (e.g., note that the term "Couette-type" is used to indicate that the flow may or may not be laminar).

[0073] As an example, the baffle may include one or more annular channels. As an example, the hub surface of the compressor impeller may include one or more annular features, such as one or more annular tips. As an example, the assembly may include a baffle having a single annular channel and a compressor impeller including a single annular tip (e.g., see channel 1083 and tip 1053 or channel 1085 and tip 1055). In such an example, the baffle may include a notch (e.g., see notch 1087). As an example, the assembly may include a baffle having one or more annular channels and a compressor impeller including one or more annular tips (e.g., see channel 1083 and tip 1053 and / or channel 1085 and tip 1055). In such an example, the baffle may include a notch (e.g., see notch 1087).

[0074] Figure 11 An exemplary table 1100 is shown, which has a set of... Figure 3 baffle 380 and Figure 10 A comparison of the values ​​of baffle 1080. As shown, while both reduce leakage and provide acceptable efficiency, baffle 380 offers improved efficiency (higher efficiency) and / or improved leakage (less leakage) compared to baffle 1080. Figure 3 and Figure 10 In the example, baffle 380 has fewer feature portions compared to the base portions of baffle 1080 and impellers 1050 and 1070, and the base portions of impellers 344-1 and 344-2 also have fewer feature portions. Thus, baffle 380 is easier to manufacture, and impellers 344-1 and 344-2 are easier to manufacture. As shown in Table 1100, baffle 380 has improved efficiency (64.96 vs. 64.88) and reduced mass flow leakage (3.3 g / s vs. 3.6 g / s) compared to baffle 1080.

[0075] Other baffle shapes were also tested. For example, a baffle with a sharp tip formed by a converging parabolic profile exhibited lower efficiency (64.81) and greater leakage (3.9 g / s) compared to baffle 380, and such a baffle with a sharp tip cut off exhibited lower efficiency (64.87) and greater leakage (4.1 g / s) compared to baffle 380. As explained, the end portion, defined by a change in concavity and including a blunt end, can at least partially improve efficiency and reduce mass flow leakage by vortex formation, wherein the vortex is deflected to the low-pressure side that provides the maximum Mach number. While such end portions can form one or more other vortices, vortices with the maximum Mach number can be formed to be deflected to the low-pressure side to at least reduce mass flow leakage.

[0076] As an example, interstage leakage can reduce overall compressor stage efficiency. As an example, an assembly including an annular baffle can be used to reduce interstage leakage between compressor stages, the annular baffle including, for example... Figure 3 One or more features of the baffle 380.

[0077] As an example, a turbocharger may include a multi-stage compressor having a high-pressure (HP) stage and a low-pressure (LP) stage, and may include a baffle that may be used to define a space relative to the HP-stage impeller and the LP-stage impeller, wherein the baffle may be used to reduce leakage through the space. In such an example, one or more of the impellers may include one or more features that may be used to partially define the space and reduce leakage through the space.

[0078] As an example, a multi-stage compressor may include one or more variable diffuser mechanisms, which, for example, can change the geometry of a diffuser section. As an example, a turbocharger may include a variable geometry turbine assembly, which, for example, may include adjustable blades (e.g., those that can change throat size, shape, etc.). As an example, a turbocharger may include a variable geometry multi-stage compressor assembly and a variable geometry turbine assembly.

[0079] As an example, the hub surface of a compressor impeller can be shaped to accommodate stress. As mentioned, compressor impellers can rotate at speeds exceeding 100,000 revolutions per minute. At such speeds, the compressor impeller may experience considerable stress. To prevent impeller bursting (e.g., blades and / or hub), the various parts of the compressor impeller can be shaped to accommodate stress. One type of bursting is blade bursting, which occurs when the centrifugal force at high speeds pulling the blades away from the central hub overcomes the mechanical strength of the root section connecting the individual blades to the hub. In this case, if the blade root is too weak, it may detach from the hub. Another type of bursting is hub bursting, which occurs when the hub to which the blades are attached reaches its strength limit and, for example, breaks into two, three, or more pieces (e.g., across the impeller's centerline). As an example, the hub can be formed as a continuous block where the internal stress is greatest at the core of the hub (e.g., the portion forming the bore) during rotation. The lower hub surface can be shaped from the core to the ends to provide core mass and less mass at the ends.

[0080] The shape of the hub surface can be bent in a way that can adapt to stress. As an example, the shape of the hub surface of a compressor impeller can be a semi-parabolic shape in cross-section (e.g., a parabolic shape). As an example, a baffle can be formed with a surface that matches at least a portion of the hub surface of the compressor impeller. In such an example, a relatively constant axial clearance can exist relative to the radial distance between the baffle and the compressor impeller.

[0081] As an example, the baffle may be formed of a material such as steel. As an example, the baffle may be formed of an alloy. As an example, the baffle may be coated with a coating. As an example, the coating may resist chemical corrosion of the baffle core material. For example, consider a multi-stage compressor assembly implemented in a system that may include exhaust gas recirculation (EGR). In such an example, the coating may resist chemical corrosion of one or more components in the exhaust gas of the internal combustion engine (e.g., which may react with one or more components in the incoming air, etc.).

[0082] As an example, a multi-stage compressor assembly may include compressor impellers made of the same material or compressor impellers made of different materials. For example, the compressor impeller may be made of aluminum or an aluminum-based alloy.

[0083] As explained, the reduced distance between the compressor backplate and the baffle allows for placement closer to the obstruction area, thus reducing leakage flow. As an example, a baffle such as baffle 380 can provide a gap in the area where, in the case of extreme shaft movement, only a small surface area may come into contact. This approach helps reduce energy loss. With the reduction in contact surface (e.g., due to a smaller diameter), any resulting material wear can be expected to have a relatively small impact on impeller balance.

[0084] As explained, the exemplary baffle reduces leakage mass flow between the LP and HP compressor stages, which can have a beneficial impact on efficiency and shaft power increments. CFD results show that the exemplary baffle 380 reduces mass flow more than the more complex baffle 1080, which also involves a more complex compressor backplate. When comparing baffles 380 and 1080, baffle 380 has a simpler profile and provides ease of manufacture.

[0085] As an example, an annular baffle for a two-stage radial compressor assembly may include an outer edge; and a generally parabolic portion extending to an end portion, wherein the end portion includes opposing sides converging radially inward to a blunt end. In such an example, the end portion may include a quadrilateral profile. For example, consider a convex quadrilateral profile.

[0086] As an example, the end portion of the annular baffle may have a convex profile. In such an example, the end portion may be adjacent to a substantially parabolic portion. As an example, the end portion may be defined at least partially by a change in concavity.

[0087] As an example, the end portion of the annular baffle may include a blunt end having a length less than the length of at least one of the opposite sides of the quadrilateral cross-section of the end portion.

[0088] As an example, the annular baffle may include an end portion that can be defined by a convex polygonal cross-section. For example, consider a quadrilateral cross-section that is convex and includes one acute angle and three obtuse angles.

[0089] As an example, the end portions of the baffle may include opposing sides, one of which is a longer side and the other a shorter side. In such an example, back-to-back compressor impellers may have different sizes and / or shapes, wherein the length difference of the opposing sides of the end portions of the baffles adapts to different sizes and / or shapes of the compressor impellers (e.g., the back disk portion of the compressor impeller, etc.).

[0090] As an example, at least one of the opposite sides of the end portion of the baffle may converge at an angle less than or equal to 90 degrees and greater than 50 degrees to the blunt end.

[0091] As an example, the blunt end of the end portion of the annular baffle may define the inner perimeter of the annular baffle. In such an example, this end portion may be the part of the annular baffle closest to the axis of rotation of the back-to-back compressor impeller. As an example, in the case where the compressor impeller comprises two faces and is formed as a single component, the annular baffle may be separable (e.g., a split baffle) such that it can be positioned between the back disk portions of the compressor impeller.

[0092] As explained, the annular baffle may include a transition region between a generally parabolic portion and an end portion. In such an example, this transition region may include opposing transition features. For example, consider a low-pressure side transition feature and a high-pressure side transition feature. As explained, the concavity may vary in the transition region, which can be expressed mathematically (e.g., according to inflection points, according to continuity, etc.).

[0093] As an example, the back disk of a compressor impeller may include a generally parabolic profile, wherein the generally parabolic profile is designed to reduce operating stresses. For example, the hub of the compressor impeller may include a hub surface that transitions from a flat end to a back disk portion having a profile designed to achieve desired stress behavior. In such an example, this profile may be defined using a parabolic equation. As explained, the compressor impeller may include a bore, which may be a through-hole. During operation, as the compressor impeller rotates, it may be subjected to various stresses. These stresses may originate from the material itself (e.g., the mass of the compressor impeller itself), from the blades (e.g., interaction with air, etc.), from clamping (e.g., axial clamping by a nut, etc.), etc. One or more types of analyses may be performed to optimize the compressor impeller with respect to its stress behavior (e.g., considering finite element analysis (FEA), etc.).

[0094] As an example, the back disk portion of the first compressor impeller may be represented by a semi-parabola or a portion thereof, and the back disk portion of the second compressor impeller may also be represented by a semi-parabola or a portion thereof. In such an example, the two semi-parabolas may join at their vertices, where the vertex does not have a value exceeding C. 0 Continuity of continuity. As an example, the backplate portion can be machined to provide continuity greater than C. 0 A continuous joint or interface. As an example, the backplate portion can be machined such that a single parabola can represent the space defined by the backplate portion when aligned back-to-back. As explained, in various cases, the backplate portion will be within C... 0 The confluence of the continuous flow points allows the annular baffle to include an end portion extending toward that confluence point (e.g., at operating temperature). In such a method, this end portion can help to block the flow from the high-pressure side to the low-pressure side.

[0095] As an example, the components may include: a first radial compressor impeller having an axis of rotation and including a hub surface; a second radial compressor impeller including a hub surface; and an annular baffle at least partially disposed between the hub surfaces, wherein the annular baffle includes an outer edge and a generally parabolic portion extending to an end portion, wherein the end portion includes opposite sides converging radially inward to a blunt end. In such an example, the first radial compressor impeller may include an axial face defined by a first diameter, and the second radial compressor impeller may include an axial face defined by a second diameter, wherein the first diameter exceeds the second diameter.

[0096] As an example, the first radial compressor impeller can be a low-pressure stage compressor impeller, and the second radial compressor impeller can be a high-pressure stage compressor impeller. In such an example, the first and second radial compressor impellers can define an annular embedding space.

[0097] As an example, at ambient temperature, the end portion of the annular baffle may be axially offset toward the high-pressure stage compressor impeller. In such an example, at operating temperature, this end portion may become more centrally located between the low-pressure and high-pressure stages due to thermal energy. As an example, when two back-to-back compressor impellers differ in material, shape, and / or size, their thermal behavior may differ. As an example, two back-to-back compressor impellers may be in different operating environments. For example, the low-pressure and high-pressure stages may differ in temperature; note that heat transfer may occur between these impellers when they are in contact. As an example, one or more thermal effects occurring during operation can be addressed by setting an annular baffle whose relative position may differ at ambient and operating temperatures.

[0098] Although some examples of methods, apparatuses, systems, arrangements, etc., have been illustrated in the accompanying drawings and described in the foregoing detailed embodiments, it will be understood that the disclosed exemplary embodiments are not limiting, but rather allow for many rearrangements, modifications, and substitutions.

Claims

1. An annular baffle for a two-stage radial compressor assembly, the annular baffle comprising: outer edge; as well as A generally parabolic portion extending to the end portion, wherein the end portion includes opposite sides converging radially inward to the blunt end, and wherein the blunt end is defined by a flat surface. The opposing sides include a low-pressure side facing the first radial compressor impeller of the two-stage radial compressor assembly and a high-pressure side facing the second radial compressor impeller of the two-stage radial compressor assembly, with the blunt end forming a sharp corner with the low-pressure side. The end portion includes a quadrilateral cross-section.

2. The annular baffle according to claim 1, wherein, The quadrilateral cross-section is convex.

3. The annular baffle according to claim 1, wherein, The blunt end includes a length that is less than the length of at least one of the opposite sides.

4. The annular baffle according to claim 1, wherein, The quadrilateral profile includes one acute angle and three obtuse angles.

5. The annular baffle according to claim 1, wherein, The opposite sides include the longer side and the shorter side.

6. The annular baffle according to claim 1, wherein, At least one of the opposite sides of the end portion converges to the blunt end at an angle less than or equal to 90 degrees and greater than 50 degrees.

7. The annular baffle according to claim 1, wherein, The blunt end defines the inner perimeter of the annular baffle.

8. The annular baffle of claim 1, comprising a transition region between the substantially parabolic portion and the end portion.

9. The annular baffle according to claim 8, wherein, The transition region includes opposing transition features.

10. A component comprising: A first radial compressor impeller has a rotation axis and includes a hub surface; The second radial compressor impeller includes a hub surface; as well as An annular baffle, at least partially disposed between the hub surfaces, includes an outer edge and a generally parabolic portion extending to an end portion, wherein the end portion includes opposite sides converging radially inward to a blunt end, and wherein the blunt end is defined by a flat surface. The opposing sides include a low-pressure side facing the first radial compressor impeller and a high-pressure side facing the second radial compressor impeller, with the blunt end forming a sharp angle with the low-pressure side. The end portion includes a quadrilateral cross-section.

11. The component of claim 10, wherein, The first radial compressor impeller includes an axial surface defined by a first diameter, and the second radial compressor impeller includes an axial surface defined by a second diameter, wherein the first diameter exceeds the second diameter.

12. The component of claim 11, wherein, The first radial compressor impeller is a low-pressure stage compressor impeller, and the second radial compressor impeller is a high-pressure stage compressor impeller.

13. The component of claim 12, wherein, The first radial compressor impeller and the second radial compressor impeller define an annular embedding space.

14. The component of claim 12, wherein, The end portion of the annular baffle is axially offset toward the impeller of the high-pressure stage compressor.

Images