Study of the axial-radial compressor stage of a turbo-expansion engine/compressor unit

1995 ◽  
Vol 31 (5) ◽  
pp. 272-274
Author(s):  
Yu. I. Blintsovskii ◽  
E. M. Smirnov
Keyword(s):  
Compressor Stage ◽  
Compressor Unit ◽  
Expansion Engine ◽  
Radial Compressor ◽  
Engine Compressor

scholarly journals Experimental investigation and numerical modelling of 3D radial compressor stage and influence of the technological holes on the working characteristics

2018 ◽  
Vol 180 ◽  
pp. 02060 ◽  
Author(s):  
Richard Matas ◽  
Tomáš Syka ◽  
Lukáš Hurda
Keyword(s):  
Experimental Investigation ◽  
Numerical Modelling ◽  
Research And Development ◽  
Evaluation Process ◽  
Rotor Blades ◽  
Compressor Stage ◽  
Experimental Facility ◽  
Radial Compressor ◽  
Measurement And Evaluation

The article deals with a description of results from research and development of a radial compressor stage with 3D rotor blades. The experimental facility and the measurement and evaluation process is described briefly in the first part. The comparison of measured and computed characteristics can be found in the second part. The last part of this contribution is the evaluation of the rotor blades technological holes influence on the compressor stage characteristics.

scholarly journals Hub and shroud fillets influence on the radial compressor stage efficiency

2015 ◽  
Vol 92 ◽  
pp. 02090 ◽  
Author(s):  
Tomáš Syka ◽  
Richard Matas ◽  
Jindřich Kňourek
Keyword(s):  
Compressor Stage ◽  
Radial Compressor ◽  
Stage Efficiency

Instability Analysis of a Centrifugal Compressor Stage Near Peak Pressure Rise

2001 ◽  
Author(s):  
Werner Jahnen ◽  
Wim-Paul Breugem ◽  
Beat Ribi
Keyword(s):  
Peak Pressure ◽  
Pressure Rise ◽  
Compressor Stage ◽  
Mass Storage ◽  
Flow Conditions ◽  
Radial Compressor ◽  
Stall Inception ◽  
Measurement Results ◽  
Different Types ◽  
The Individual

It is often observed that radial compressor stages exhibit different types of instabilities dependent on the rotor-diffuser matching. The onset of instability may be before, at, or after the slope of the pressure rise characteristic becomes zero during throttling. In this study the flow conditions in the individual stage components at instability onset have been investigated experimentally and theoretically to allow an improvement of present prediction methods. Within the scope of the experimental study separate characteristics of the rotor and the diffuser have been recorded in detail while unsteady measurements have been performed simultaneously. The measurement results show that rotor and/or diffuser instability affects overall stage stability. The nature of stage component stability suggests that rotor and diffuser can be excited as subsystems. For an improved understanding, numerical investigations based on the Moore-Greitzer (1986) model have been performed. In order to account for the observed subsystem properties of rotor and diffuser, the model had to be extended, and was adapted to the geometry of the investigated radial compressor stage. By implementing inner stage mass storage and flow redistribution capability into the model, a decoupled treatment of stage components was accomplished. The numerical results are in qualitative agreement with the measurements, and prove that a decoupled treatment of rotor and diffuser in radial compressor stages is able to describe stall inception more accurately.

Analysis of Unsteady Flow in a Supercritical Carbon Dioxide Radial Compressor Stage

2018 ◽  
Author(s):  
Can Ma ◽  
Wei Wang ◽  
Jun Wu ◽  
Lu Dai
Keyword(s):  
Unsteady Flow ◽  
Critical Point ◽  
Supercritical Co2 ◽  
Nuclear Power ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Rankine Cycle ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Radial Compressor

For nuclear power system, the supercritical CO2-based Brayton cycle is very promising for its potentially higher efficiency and compactness compared to steam-based Rankine cycle. Compressor is the critical component in the supercritical CO2-based cycle, which typically operates at an inlet fluid state close to the fluid critical point for optimal cycle efficiency. As the fluid parameters vary significantly near the critical point, the compressor is more vulnerable to flow instabilities and care must be taken in designing the compressor. The supercritical CO2 radial compressor features a compact design and the unsteady interactions between the impeller and the vaned diffuser are typically strong. A comprehensive understanding of the unsteady flow effects in the compressor is very helpful in guiding the aerodynamic design. However, little work has been performed on the flow analysis of the unsteady impeller-diffuser interactions in the supercritical CO2 radial compressor. In this work, the unsteady flow simulation of a supercritical CO2 radial compressor stage is carried out. Strong flow unsteadiness is observed and the isentropic efficiency shows a variation of over 20% within one revolution.

Investigations on a Radial Compressor Tandem-Rotor Stage With Adjustable Geometry

1992 ◽  
Author(s):  
B. Josuhn-Kadner ◽  
B. Hoffmann
Keyword(s):  
Flow Field ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Radial Compressor ◽  
Design Point ◽  
Small Influence ◽  
Point Condition ◽  
And Performance ◽  
Operating Points

A radial compressor stage has been investigated mainly experimentally for aerodynamic stage optimization. The rotor (πt = 3.9) consists of a profiled axial inducer and a conventionally designed radial impeller. Inducer and impeller can be locked at different circumferential positions relative to each other thus, forming a tandem wheel with adjustable geometry. Conventional and Laser-2-Focus system measurements for the tandem-rotor and the stage were performed at different operating points to study the influence of the circumferential clearance geometry between inducer and impeller with respect to compressor characteristics and performance. Furthermore, 3-D Navier-Stokes calculations are being developed at design point condition to analyse the flow field. Small influence of the inducer adjustment on the rotor characteristics is observed. The maximum rotor efficiency of 93.5 % varies in a range of less than 1 % depending on the different inducer positions.

Influence of a Closely Coupled Throttle on the Stalling Behavior of a Radial Compressor Stage

1985 ◽  
Vol 107 (2) ◽  
pp. 522-527 ◽  
Author(s):  
J. W. Railly ◽  
H. Ekerol
Keyword(s):  
Rotating Stall ◽  
Compressor Blade ◽  
Compressor Stage ◽  
Slow Speed ◽  
Radial Compressor ◽  
Pressure Characteristic ◽  
Static Instability ◽  
The Stability ◽  
Stage Characteristic ◽  
Radial Gap

On the basis of the classical discussion of the stability of compressor blade rows, a treatment is given of the stability of a stage consisting of a radial impeller followed by a vaned radial diffuser with a small radial gap between them. At the exit of the diffuser a radial array of adjustable vanes serves either to throttle the flow or to offer no resistance. In the latter case, throttling takes place by means of restrictions at inlet situated well upstream. The theory demonstrates that instability in the former case can only occur at the point of static instability, i.e., when the stage pressure characteristic slope becomes so positive that the throttle pressure characteristic is tangential to it. With the conventional throttling arrangement, instability is predicted as expected, when the stage characteristic has zero slope. Experimental confirmation of these predictions was obtained from tests on a slow speed radial compressor stage employing the above arrangement at exit, dischanging to atmosphere. When the vanes were used for throttling no rotating stall appeared but with throttling situated remotely from the stage a vigorous rotating stall mode developed.

Investigations on a Radial Compressor Tandem-Rotor Stage With Adjustable Geometry

1993 ◽  
Vol 115 (3) ◽  
pp. 552-559 ◽  
Author(s):  
B. Josuhn-Kadner ◽  
B. Hoffmann
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Radial Compressor ◽  
Design Point ◽  
Small Influence ◽  
Point Condition ◽  
And Performance ◽  
Operating Points

A radial compressor stage has been investigated mainly experimentally for aerodynamic stage optimization. The rotor (πt = 3.9) consists of a profiled axial inducer and a conventionally designed radial impeller. Inducer and impeller can be locked at different circumferential positions relative to each other, thus forming a tandem wheel with adjustable geometry. Conventional and Laser-2-Focus system measurements for the tandem rotor and the stage were performed at different operating points to study the influence of the circumferential clearance geometry between inducer and impeller with respect to compressor characteristics and performance. Furthermore, three-dimensional Navier–Stokes calculations are being developed at design point condition to analyze the flow field. A small influence of the inducer adjustment on the rotor characteristics is observed. The maximum rotor efficiency of 93.5 percent varies in a range of less than 1 percent depending on the different inducer positions.

scholarly journals EXPERIMENTAL AND THEORETICAL INVESTIGATION OF LOSSES IN A RADIAL COMPRESSOR STAGE

1991 ◽  
Vol 4 (ASAT CONFERENCE) ◽  
pp. 1-8
Author(s):  
K. Saad Eldin ◽  
Ibrahim Saleh ◽  
Ali Elzahabi ◽  
Salah Elfeki
Keyword(s):  
Theoretical Investigation ◽  
Compressor Stage ◽  
Radial Compressor

The Influence of Impeller Flow Channel Modification on Aerodynamic Performance of a Centrifugal Compressor Stage

1998 ◽  
Author(s):  
Jan Paroubek ◽  
Jiří Kynčl
Keyword(s):  
Aerodynamic Performance ◽  
Relative Width ◽  
Compressor Stage ◽  
Blade Angle ◽  
Test Rig ◽  
Radial Compressor ◽  
Channel Form ◽  
Flow Channels ◽  
Blade Thickness ◽  
Impeller Outlet

The modifications of meridional form and blade thickness of the impeller of an industrial radial compressor stage (impeller outlet blade angle 32 deg., relative width parameter 0.05) have been designed to extend the operating range of the stage in the area of higher flow rates and to reduce aerodynamic losses in this region. Quasi-3D calculations of the flow pattern in both original and modified impeller flow channels have been carried out to assess the influence of channel form change. The aerodynamic performance of the stage operating with both impellers has been tested on a test rig. The original stage was equipped with varied diffuser only, the modified one was tested with both vaned and vaneless diffusers. Detailed measurements of the flow field behind the impeller outlet have also been carried out. The results of these investigations are presented. Aerodynamic performance and losses in individual flow parts of the stages are compared and discussed.

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