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Showing papers on "Axial compressor published in 1991"


Journal ArticleDOI
TL;DR: In this paper, a linear cascade with tip clearance is complemented by numerical solutions of the three-dimensional Navier-Stokes equations in an investigation of tip leakage flow, and detailed comparisons show that the mechanism of leakage is primarily inviscid.
Abstract: Experimental measurements in a linear cascade with tip clearance are complemented by numerical solutions of the three-dimensional Navier–Stokes equations in an investigation of tip leakage flow. Measurements reveal that the clearance flow, which separates near the entry of the tip gap, remains unattached for the majority of the blade chord when the tip clearance is similar to that typical of a machine. The numerical predictions of leakage flow rate agree very well with measurements, and detailed comparisons show that the mechanism of tip leakage is primarily inviscid. It is demonstrated by simple calculation that it is the static pressure field near the end of the blade that controls chordwise distribution of the flow across the tip. Although the presence of a vortex caused by the roll-up of the leakage flow may affect the local pressure field, the overall magnitude of the tip leakage flow remains strongly related to the aerodynamic loading of the blades.

239 citations


Journal ArticleDOI
TL;DR: In this article, the authors used temporally and spatially resolved measurements to study the evolution of rotating stall cells in low speed compressors and high speed three-stage compressors.
Abstract: Stall inception has been studied in two low speed compressors (a single-stage and a three-stage) and in a high speed three-stage compressor, using temporally and spatially resolved measurements. In all three machines, rotating stall was preceded by a period in which small amplitude waves were observed travelling around the circumference of the machine at a speed slightly less than the fully developed rotating stall cell speed. The waves evolved smoothly into rotating stall without sharp changes in phase or amplitude, implying that, in the machines tested, the prestall waves and the fully developed rotating stall are two stages of the same phenomenon. The growth rate of these disturbances was in accord with that predicted by current analytical models. The prestall waves were observed both with uniform and with distorted inflow, but were most readily discerned with uniform inflow. Engineering uses and limitations of these waves are discussed.Copyright © 1990 by ASME

180 citations


Proceedings ArticleDOI
03 Jun 1991
TL;DR: In this paper, it was shown that modal perturbations are not always present prior to stall, and when present, sometimes have little direct effect on the formation of the stall cells.
Abstract: Studies have been conducted on two laboratory test compressors to investigate the process leading to the formation of finite amplitude rotating stall cells. The measurements were obtained from circumferential arrays of hot-wires and were spatially and temporarily analysed to show that modal perturbations are not always present prior to stall, and when present, sometimes have little direct effect on the formation of the stall cells. The measurements lead to the conclusion that the occurrence of modal perturbations, and the formation of finite amplitude stall cells, are two separate phenomena; both occurring under roughly the same conditions at the peak of the pressure rise characteristic. The measurements also underline the hitherto unsuspected importance of short length scale disturbances in the process of stall inception. Examples are given of different ways in which stall cells can develop and the conclusions are backed up with a summary of current test data from various machines around the world.Copyright © 1991 by ASME

143 citations


Patent
24 May 1991
TL;DR: A brushless DC motor has a rotor (10) with impeller blades (50) mounted thereon to pump blood through the central portion of the motor as mentioned in this paper, and the rotor has a cylindrical surface (20) that is spaced from a cooperating cylinrical surface on the motor stator.
Abstract: A brushless DC motor has a rotor (10) with impeller blades (50) mounted thereon to pump blood through the central portion of the motor. Over a portion of its length, the rotor (10) has a cylindrical surface (20) that is spaced from a cooperating cylindrical surface on the motor stator. There is a gap between these cylindrical surfaces through which there is a leakage flow of blood. The relative motion between the cylindrical surfaces provides a hydrodynamic bearing that suspends the rotor in the stator.

117 citations


Proceedings ArticleDOI
03 Jun 1991
TL;DR: In this paper, two distinctly different methods were used to delay the onset of rotating stall in a four-stage compressor using fast acting air injection valves, and the results showed an improvement of about 4.0% in stall margin.
Abstract: This paper reports on an experimental program in which active control was successfully applied to both rotating stall and surge in a multi-stage compressor. Two distinctly different methods were used to delay the onset of rotating stall in a four stage compressor using fast acting air injection valves. The amount of air injected was small compared to the machine mass flow, the maximum being less than 1.0%. In some compressor configurations modal perturbations were observed prior to stall. By using the air injection valves to damp out these perturbations an improvement of about 4.0% in stall margin was achieved. The second method of stall suppression was to remove emerging stall cells by injecting air in their immediate vicinity. Doing this repeatedly delayed the onset of stall, giving a stall margin improvement of about 6.0%. Further studies were conducted using a large plenum downstream of the compressor to induce the system to surge rather than stall. The resulting surge cycles were all found to be initiated by rotating stall and therefore the stall suppression systems mentioned above could also be used to suppress surge. In addition, it was possible to arrest the cyclical pulsing of a compressor already in surge.Copyright © 1991 by ASME

91 citations


Patent
19 Aug 1991
TL;DR: In this article, a method for controlling gas flow in an axial flow compressor is proposed, in which the flow at one or more chosen station in the direction of flow through the compressor is sensed at a series of circumferentially spaced positions.
Abstract: The method controls gas flow in an axial flow compressor in which the flow at one or more chosen station in the direction of flow through the compressor is sensed at a series of circumferentially spaced positions. Flow variations above a predetermined limit are evaluated to initiate a response if a disturbance above a predetermined acceptable level is detected. When such a disturbance is detected, higher pressure gas bled from downstream is injected at a station to supplement the main gas flow. An incipient rotating stall cell will appear as a variation occurring sequentially at the circumferentially spaced positions. By responding to such a condition with a pressure injection, it is found possible to suppress both rotating stall and surge conditions in the compressor before this disturbance develops fully. The same method can be arranged to counter steady state distortion.

77 citations


Proceedings ArticleDOI
03 Jun 1991
TL;DR: In this article, the onset of rotating stall has been delayed in a low speed, single-stage, axial research compressor using active feedback control, which was implemented using a circumferential array of hot wires to sense rotating waves of axial velocity upstream of the compressor.
Abstract: The onset of rotating stall has been delayed in a low speed, single-stage, axial research compressor using active feedback control. Control was implemented using a circumferential array of hot wires to sense rotating waves of axial velocity upstream of the compressor. Circumferentially travelling waves were then generated with appropriate phase and amplitude by “wiggling” inlet guide vanes driven by individual actuators. The control scheme considered the wave pattern in terms of the individual spatial Fourier components. A simple proportional control law was implemented for each harmonic. Control of the first spatial harmonic yielded an 11% decrease in the stalling mass flow, while control of the first and second harmonics together reduced the stalling mass flow by 20%. The control system was also used to measure die sine wave response of the compressor, which behaved as would be expected for a second order system.Copyright © 1991 by ASME

73 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated statistical characteristics of pressure fluctuation on the casing wall of two axial flow compressor rotors to find a precursor of rotating stall, which can be detected by monitoring collapse of the periodicity in the pressure fluctuations.
Abstract: Statistical characteristics of pressure fluctuation on the casing wall of two axial flow compressor rotors have been investigated experimentally to find a precursor of rotating stall. Near stall, the casing wall pressure across a flow passage near the leading edge is characterized by a highly unsteady region where low-momentum fluid accumulates. The periodicity of the pressure fluctuation with blade spacing disappears and an alternative phenomenon comes into existence, which supports the disturbance propagating at a different speed from the rotor revolution. The precursor of rotating stall can be detected by monitoring collapse of the periodicity in the pressure fluctuation. To represent the periodicity qualitatively, a practical detection parameter has been proposed, which is easily obtained from signals of a single pressure sensor installed at an appropriate position on the casing wall during operation of a compressor.

54 citations


Patent
24 Jun 1991
TL;DR: In this article, a radial inflow particle separator (40) is employed with a turbine engine, which is operated at times in an environment laden with dust and particulate matter.
Abstract: A radial inflow particle separator (40) includes a pair of axially and radially spaced curvilinear walls (42, 44) cooperatively defining a circumferential flow path (16) leading radially inwardly and axially to an engine. Preferably, the particle separator (40) is employed with a turbine engine (10) which is operated at times in an environment laden with dust and particulate matter. Such an environment is typically encountered by a turbine engine (10) of a helicopter, or off-road vehicle. The particle separator (40) provides dust and particulate control features including aero-inertial, particle trajectory, particle boundary-rebound, and scavenge flow tailoring to achieve a dust and particulates separation efficiency as good as or better than the best conventional axial-flow particle separators. This particle separation effectiveness is achieved in a radial inflow particle separator (40) which is smaller and lighter in weight than axial flow devices, and which packages advantageously with the essential structures of a turbine engine.

49 citations


Journal ArticleDOI
TL;DR: In this article, a cascade profile representative for the first rotor hub section of an industrial compressor has been designed by optimizing the suction surface velocity distribution using a direct boundary layer calculation method.
Abstract: Similar to jet engine development, modern design methods are used today to improve the performance of industrial compressors. In order to verify the loading limits, a cascade profile representative for the first rotor hub section of an industrial compressor has been designed by optimizing the suction surface velocity distribution using a direct boundary layer calculation method. The blade shape was computed with an inverse full potential code and the resulting cascade was tested in a cascade wind tunnel. The experimental results confirmed the design intent and resulted in a low loss coefficient of 1.8 percent at design condition and an incidence range of nearly 12 deg (4 percent loss level) at an inlet Mach number of 0.62.

48 citations


Book ChapterDOI
TL;DR: In this paper, the authors introduce the fundamental work carried out in the experimental and theoretical research of the induced rotational flow between coaxial cylinders and review the state of knowledge pertaining to the associated heat and mass transport.
Abstract: Publisher Summary This chapter introduces the fundamental work carried out in the experimental and theoretical research of the induced rotational flow between coaxial cylinders. It reviews the state of knowledge pertaining to the associated heat and mass transport. It is observed that convective transport phenomena in rotating systems are intimately related to the flow characteristics. This feature, together with the three-dimensionality of the boundary layer flow, coupled with centrifugal and Coriolis forces, demonstrates a very complicated system. The chapter essentially concerns the nature of induced rotating flow and the associated heat and mass transfer between coaxial cylinders, primarily when the inner cylinder is rotating and the outer is at rest. It also examines prevailing flow regimes, transition, and stability aspects, and deals with mass-transfer phenomena with and without reactions. The sequence of transitions, as the speed of rotation is increased gradually, involves steady flow, periodic flow, quasiperiodic flow, and turbulent flow. Demarcation lines between the various flow regimes have been experimentally established for various system geometries with and without an imposed axial flow.

Patent
Yasumi Irino1
09 May 1991
TL;DR: In this paper, the capacity variable range of the compressor can be increased with a simple structure including one counterflow checking means and one switching means, and the switching means is operated such that the refrigerant gas compressed by the second compressor is let to flow into the sealed casing to perform a parallel compression operation with use of the first and second compressor means.
Abstract: A refrigerating cycle apparatus has, in a sealed casing, a compressor including first and second compressor means driven simultaneously. A refrigerating cycle circuit is constituted by connecting this compressor, a condenser, a pressure-reducing device, and an evaporator. Counterflow checking means is provided on the suction side of the first compressor means, for checking the counterflow of the refrigerant from the first compressor means to the evaporator. Switching means is provided on the discharge side of the second compressor means. The switching means is operated such that the refrigerant gas compressed by the second compressor means is let to flow into the sealed casing to perform a parallel compression operation with use of the first and second compressor means, and the refrigerant gas compressed by the second compressor means is let to flow from the downstream side of the counterflow checking means to the suction side of the first compressor means, thereby performing a two-stage compression operation in which compression is performed first by the first compressor means and then by the second compressor means. The capacity variable range of the compressor can be increased with a simple structure including one counterflow checking means and one switching means.

Patent
30 Jul 1991
TL;DR: An axial flow fan has each of its fan blades provided with an integrally formed centrifugal element which extends substantially parallel to an imaginary plane containing a central axis of the fan.
Abstract: An axial flow fan has each of its fan blades provided with an integrally formed centrifugal element which extends substantially parallel to an imaginary plane containing a central axis of the fan. Some of the air flow passing through the fan collides against the centrifugal elements, which deflect the air in the radial directions. A disk-like air barrier is thus formed around the fan blades, whereby a countercurrent flow and circulation flow are eliminated. The fan efficiency is also improved.

Patent
09 Jan 1991
TL;DR: In this article, a combination of a variable reluctance motor and a screw compressor is provided with a fluid management system that directs a portion of the lubricant flow through the VL motor to cool its stator laminations and windings.
Abstract: A combination of a variable reluctance motor and a screw compressor is provided with a fluid management system that directs a portion of the lubricant flow through the variable reluctance motor to cool its stator laminations and windings Another portion of the lubricant flow is caused to pass directly from a heat exchanger to the screw compressor The first portion of flow, which passes through the variable reluctance motor, is then directed into fluid communication with the inlet of the screw compressor to lubricate the screw compressor and provide cooling for the compressor The portion of lubricant flow passing directly through the heat exchanger to the compressor also provides lubrication for the compressor and is used to further cool the moving parts of the screw compressor

Journal ArticleDOI
TL;DR: In this paper, a numerical technique for the solution of the gas dynamics equations is described, based on the transfer matrix formulation relating the state vector time difference at one side of an element to that on the other side.
Abstract: Dynamic simulation of the operation of a compressor station requires mathematical modeling of the dynamic behavior of the compressor unit and various piping elements. Such models consist of large systems of nonlinear partial differential equations describing the pipe flow together with nonlinear algebraic equations describing the quasi-steady flow through various valves, constrictions, and compressors. In addition, the models also include mathematical descriptions of the control system, which consists of mixed algebraic and ordinary differential (mad) equations with some inequalities representing controllers' limits. A numerical technique for the solution of the gas dynamics equations is described, based on the transfer matrix formulation relating the state vector time difference at one side of an element to that on the other side. Simulation results and comparison with actual field measurements of three case histories: simulation of a compressor surge protection control process, unit startup, and slow transient of a compressor station responding to changes in the discharge pressure set point

Patent
09 May 1991
TL;DR: In this paper, a compact centrifugal fan that draws air in past the impeller hub, which encloses a motor and which spins about a central axis, and then urges the air through a bend in the fluid passageway.
Abstract: A compact centrifugal fan that draws air in past the impeller hub, which encloses a motor and which spins about a central axis, and then urges the air through a bend in the fluid passageway. As the air passes through the annular inlet channel about the impeller hub, it flows in a forward axial direction. The air passes through the bend in the fluid passageway, as the air is being swept around the hub by the blades of the impeller. After the air passes through the bend, it has a reverse axial flow component, in addition to a circumferential flow component. Air having a forward axial flow component passes by the portion of an impeller blade that is closest to the impeller hub, and air having a reverse axial flow component passes the portion of a blade that is furthest from the impeller hub.

Journal ArticleDOI
TL;DR: In this article, the authors present a proposed index showing the susceptibility of compressors to fouling, which could be useful in helping operators to determine cleanup intervals, and three engines of widely differing performance were used in developing this index.
Abstract: Although the overall effect of compressor fouling on engine performance has been recognized for many years, remarkably little has been published on the quantifiable effects. Mathematical modelling of compressors using stage stacking methods has recently been used for a systematic study of compressor fouling and earlier investigations led to an interest in the effects of engine size and compressor stage loading. This paper presents a proposed index showing the susceptibility of compressors to fouling, which could be useful in helping operators to determine cleanup intervals. Three engines of widely differing performance were used in developing this index and additional operator experience would be useful in confirming its validity.Copyright © 1990 by ASME

Journal ArticleDOI
15 Feb 1991-EPL
TL;DR: In this article, Couette-Taylor flow between cylinders with a superimposed axial flow is studied experimentally and the surprising coexistence of steady Ekman and propagating Taylor vortices close to the inlet and outlet boundaries is discovered.
Abstract: Couette-Taylor flow between cylinders with a superimposed axial flow is studied experimentally. The axial flow suppresses the basic stationary instability and leads to propagating Taylor vortices through a forward oscillatory bifurcation. While the throughflow velocity increases the propagating vortices are pushed downstream to the outlet so that at the velocity which corresponds to the absolute instability limit, the pattern is "blown" out of the system. The surprising coexistence of steady Ekman and propagating Taylor vortices close to the inlet and outlet boundaries was discovered. The wave number selection mechanism, similar to that existing in the front-propagating case, is also identified.

Proceedings ArticleDOI
26 Jun 1991
TL;DR: In this article, the authors developed a model for the design of active surge control/rotating stall avoidance systems in aircraft gas turbine engines based on engine component steady state performance maps and unsteady quasi one-dimensional flow equations.
Abstract: The focus of this paper is on the development of models for use in the design of active surge control/rotating stall avoidance systems in aircraft gas turbine engines. Model development is illustrated for the case of a single-spool, centrifugal compressor, turbojet engine currently housed within the LICCHUS experimental facility at Georgia Tech. This engine is equipped with high bandwidth fuel flow, nozzle area, and compressor discharge bleed area servos. The model developed for this engine is based on engine component steady state performance maps and unsteady quasi one-dimensional flow equations. The latter are rigorously developed herein. Special attention is paid to the assumptions underlying the model development, particularly those pertaining to the unsteady flow aspects of the model and its dynamic order. The resulting model has three control inputs, three states, and incorporates the dynamic linkage of the compressor and turbine through the spool. The three states are compressor mass flow, plenum pressure, and spool speed. Simulation results are given for the model which indicate that the model is capable of predicting and modeling surge phenomena. Because of its quasi one-dimensional nature, the model is not capable of predicting and modeling rotating stall per se. However, the model is capable of predicting and modeling the state of rotating stall as a condition of steady, greatly reduced, annulus-averaged compressor mass flow rate, and thus is adequate for the design of rotating stall avoidance systems. Additional simulation results are given which show the response of the model to the various control inputs.

Journal ArticleDOI
TL;DR: In this paper, the influence of inlet swirl distortions on the performance of a transonic two-stage axial compressor installed in a turbo jet bypass engine Larzac 04 was investigated.
Abstract: Aeroengine intakes containing S-shaped diffusers produce different types of inlet swirl distortions and essentially a combination of a twin swirl and a bulk swirl. The main object of this investigation was to assess the influence of inlet swirl distortions on the performance of a transonic two-stage axial compressor installed in a turbo jet bypass engine Larzac 04. A typical inlet swirl distortion was simulated by a delta-wing in front of the engine. An experimental method was investigated to measure the performance map of the installed low pressure compressor for different engine operating lines. The influence of an inlet swirl distortion with different strengths on the performance map of the compressor was investigated experimentally. It is shown that the performance parameters decrease and a temperature distortion is generated behind the compressor. As the basis of the theoretical investigations of the performance map including inlet swirl distortions a computing model considering four compressors working in parallel was established. The model is based on the idea that an inlet swirl distortion can be substituted by two fundamental types of swirl components, i.e. a bulk swirl co-rotating, and a bulk swirl counter-rotating to the revolution of the compressor. Computed performance maps of the compressor will be discussed and compared with the experimental data.Copyright © 1990 by ASME

Journal Article
TL;DR: In this article, experimental and numerical results are presented for oscillatory flows and the increasing complexity of the developing eddy motion is followed to the point where the axial symmetry of the flow is broken.
Abstract: Periodic baffles are either posioned at the wall or centre of the tube. In both cases numerical simulations are presented for steady axial flow within the tube up to a net flow Reynolds number of 200. In addition, experimental and numerical results are presented for oscillatory flows and the increasing complexity of the developing eddy motion is followed to the point where the axial symmetry of the flow is broken.

Patent
18 Sep 1991
TL;DR: In this article, an axial-flow blower of stator vane controllable pitch type has an upstream-side opening of an air separator on the upstream side of a controllability pitch type inlet guide vane.
Abstract: An axial-flow blower of stator vane controllable pitch type has an upstream-side opening of an air separator on the upstream side of a controllable pitch type inlet guide vane so that the recirculating flow in the air separator can be joined smoothly with the axial main flow irrespective of the set angle of controllable pitch angle

Journal ArticleDOI
TL;DR: In this article, the second stage of a two-stage compressor was studied with two-component LDV system and the data set revealed rotor and stator wake structure and decay in both the stationary and rotating frames of reference.
Abstract: The fluid dynamics of turbomachines are extremely complex, due in part to the aerodynamic interactions between rotors and stators. It is necessary to acquire fluid dynamic data that reflect the interactive nature of a turbomachine to correlate with the fluid dynamics predicted from modern analyses. The temporal and spatial variations in the midspan aerodynamics of the second stage of a two-stage compressor have been studied with a two-component LDV system. Spatial variations were examined by traversing the LDV probe volume through a dense matrix of both axial and circumferential positions, while temporal resolution was achieved by acquiring all data as a function of the instantaneous rotor position. Hence, the data set reveals rotor and stator wake structure and decay in both the stationary and rotating frames of reference. The data also compared very favorably with extensive pneumatic measurements previously acquired in this compressor. In Part 2 of the paper, the data are used in the assessment of a prediction of the flow in the compressor using a time-accurate, thin-layer, two-dimensional Navier–Stokes analysis.

Proceedings ArticleDOI
03 Jun 1991
TL;DR: In this paper, the effect of difference in rotor tip clearance on the mean flow fields and unsteadiness and mixing across a stator blade row were investigated using hot-wire anemometry, pressure probes, flow visualization and the ethylene tracer-gas technique on a single stage axial flow compressor.
Abstract: The effect of difference in rotor tip clearance on the mean flow fields and unsteadiness and mixing across a stator blade row were investigated using hot-wire anemometry, pressure probes, flow visualization and the ethylene tracer-gas technique on a single stage axial flow compressor. The structure of the three-dimensional flow fields was discussed based on results of experiments using the 12-orientation single slanted hot-wire technique and spectrum analysis of velocity fluctuation. High-pass filtered measurements of turbulence were also carried out in order to confirm small-scale velocity fluctuation which is more realistically referred to as turbulence. The spanwise distribution of ethylene gas spreading, estimated by the measured small-scale velocity fluctuation at the rotor exit, agreed quite well with that which was experimentally measured. This fact suggests the significant role of turbulence, generated within the rotor, in the mixing process across the downstream stator. The value of the maximum mixing coefficient in the tip region was found to increase linearly as the tip clearance became enlarged, starting from the value at midspan.Copyright © 1991 by ASME

01 Jan 1991
TL;DR: The LTT Reference LTT-CONF-1991-005 Record created on 2007-04-18, modified on 2017-05-10 as mentioned in this paper, was used for this article.
Abstract: Keywords: Unsteady Flows ; Turbomachinery ; GTT ; LTT Reference LTT-CONF-1991-005 Record created on 2007-04-18, modified on 2017-05-10


Patent
Sato Takeshi1, Yoshiaki Yamazaki1
16 Sep 1991
TL;DR: In this article, an axial flow turbine with stationary blades with tangential lean angles at the leading edge and the trailing edge of the stationary blade corresponding to the flow direction of the elastic fluid is presented.
Abstract: The present invention provides an axial flow turbine, comprising a diverging flow channel for flowing of an elastic fluid, and stationary blades which are fixed at the diverging flow channel wall and are curved in a perpendicular direction to the flow direction of the elastic fluid, characterized in forming the same tangential lean angles at the leading edge and the trailing edge of the stationary blade corresponding to the flow direction of the elastic fluid, and an axial flow turbine having the stationary blades thereof. The stationary blade makes distribution of the fluid in the flow channel uniform and, consequently, improves the efficiency of the flow.

Journal ArticleDOI
TL;DR: In this article, the aerodynamic performance of a modified version of the Wells turbine, whose rotor blades can be set at varying angle (as in a Kaplan turbine) while the turbine is in motion, is investigated.
Abstract: The Wells turbine is an axial-flow air-turbine designed to extract energy from the ocean waves. The turbine is self-rectifying, ie.e., produces and unidirectional time-averaged torque from a reciprocating flow. The paper describes an experimental investigation on the aerodynamic performance of a modified version of the Wells turbine, whose rotor blades can be set at varying angle (as in a Kaplan turbine) while the turbine is in motion. The purpose of the work is to investigate whether, and to what extent, the modification to the turbine can enable it to achieve phase control-a method of tuning the energy-absorbing device to the incident waves-and avoid aerodynamic stall on the turbine rotor blades at peaks of air flow rate under conditions of real irregular ocean waves. Experimental results obtained with a model turbine are compared with predicted values from a quasi-three-dimensional computational method of flow analysis.

Patent
28 May 1991
TL;DR: In this article, a Centrifugal Gas Compressor expander for use in refrigeration system where low temperature level energy rejected from the condenser is recovered and used to produce kinetic energy to assist driving the compressor, and thus reducing the electric power required for refrigeration.
Abstract: Centrifugal gas compressor - expander for use in refrigeration system where low temperature level energy rejected from the condenser is recovered and used to produce kinetic energy to assist driving the compressor, and thus reducing the electric power required for refrigeration.

Proceedings ArticleDOI
03 Jun 1991
TL;DR: A simple efficiency correlation was derived for advanced single-stage centrifugal compressors as mentioned in this paper, based upon four critical parameters:• Inlet Specific Speed• Impeller Tip Diameter• Inducer Tip Relative Mach Number• Exit Discharge Mach Number.
Abstract: The thrust of most recent advances in single– and two–stage centrifugal compressor technology by the aerospace community has been motivated by interest in increasing airbreathing propulsion system power density, and improving specific fuel consumption with higher stage pressure ratios. Advances in the last decade have made it appropriate to review the major design parameters influencing the efficiency levels of single–stage centrifugal compressors for aircraft applications.A simple efficiency correlation was derived for advanced single–stage centrifugal compressors. It was based upon four critical parameters:• Inlet Specific Speed• Impeller Tip Diameter• Inducer Tip Relative Mach Number• Exit Discharge Mach NumberThe correlation was shown to predict attainable state–of–the–art efficiencies within a band width of ± 2 % points. This was considered acceptable for preliminary compressor and engine design work.Copyright © 1991 by ASME