scholarly journals Stability management of high speed axial flow compressor stage through axial extensions of bend skewed casing treatment

2016 ◽  
Vol 5 (3) ◽  
pp. 236-249 ◽  
Author(s):  
DilipkumarBhanudasji Alone ◽  
S. Satish Kumar ◽  
Shobhavathy M. Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A.M. Pradeep ◽  
...  
Keyword(s):  
High Speed ◽  
Axial Flow ◽  
Compressor Stage ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Flow Compressor

Experimental Investigation on the Effect of Porosity of Bend Skewed Casing Treatment on a Single Stage Transonic Axial Flow Compressor

2014 ◽  
Author(s):  
Dilipkumar B. Alone ◽  
Subramani Satish Kumar ◽  
Shobhavathy Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A. M. Pradeep ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Axial Flow ◽  
Compressor Stage ◽  
Casing Treatment ◽  
Operating Range ◽  
Axial Flow Compressor ◽  
Transonic Compressor ◽  
Stable Operating ◽  
Flow Compressor ◽  
Casing Treatments

A bend skewed casing treatment was designed, to study the influence of one of its geometrical parameter porosity on the stable performance of single stage transonic axial flow compressor. The compressor was designed for the stage total-to-total pressure ratio of 1.35, corrected mass flow rate of 22 kg/s at corrected design speed of 12930 RPM. Bend skewed casing treatment has an axial inlet segment till 50% of the total length and rear segment that is skewed by 45° in the direction of the rotor tip section stagger. Both the sections were oriented at a skew angle of 45° to the radial plane such that the flow exiting the slot is in counter-clockwise direction to that of the rotor direction. The casing treatment slot width was equal to the maximum thickness of the rotor blades. Three casing treatment configurations were identified for the current experimental investigation. All the treatment geometries considered for the experimental research have lower porosities than reported in the open literatures. The effect of the porosity parameter on the performance of transonic compressor stage was evaluated at two axial coverages of 20% and 40% relative to the rotor tip axial chord. Performance maps were obtained for the solid casing and casing treatment with three different porosities. Comparative studies were carried out and experimental results showed a maximum of 65% improvement in the stable operating range of the compressor for one of the treatment configurations. It was also observed that the stable operating range of the compressor increases with an increase in the casing treatment porosity. All the casing treatment configurations showed that the compressor stall occurs at lower mass flows as compared to the solid casing. Compressor stage peak efficiency shows significant degradations with increase in the porosity as compared to solid casing. Detailed blade element performances were also obtained using calibrated multi-hole aerodynamic probe. Comparative variations of flow parameters like absolute flow angle, Mach number were studied at full flow and near stall conditions for the solid casing and casing treatment configurations. Hot wire measurements show very high fluctuation in the inlet axial velocity in the presence of solid casing as compared to casing treatments. Experimental investigation revealed that the porosity of the casing treatments has strong influence on the transonic compressor stage performance.

Aerodynamic behavior of a transonic axial flow compressor stage with self-recirculating casing treatment

2021 ◽  
pp. 106587
Author(s):  
S Satish Kumar ◽  
Dilipkumar Bhanudasji Alone ◽  
Shobhavathy M Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
Lakshya Kumar ◽  
...  
Keyword(s):  
Axial Flow ◽  
Compressor Stage ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Flow Compressor

On Understanding the Effect of Plenum Chamber of a Bend Skewed Casing Treatment on the Performance of a Transonic Axial Flow Compressor

2014 ◽  
Author(s):  
Dilipkumar B. Alone ◽  
Subramani Satish Kumar ◽  
Shobhavathy Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A. M. Pradeep ◽  
...  
Keyword(s):  
Axial Flow ◽  
Single Stage ◽  
Compressor Stage ◽  
Stall Margin ◽  
Casing Treatment ◽  
Plenum Chamber ◽  
Axial Flow Compressor ◽  
Chamber Volume ◽  
Stable Operating ◽  
Flow Compressor

Bend skewed casing treatment was designed to improve the stable operating range of single stage transonic axial flow compressor and also to understand the effects of its plenum chamber volume on the performance. This paper presents the original experimental research work undertaken to study the effect of plenum chamber depth and thus its volume on the performance of single stage transonic axial flow compressor coupled with the bend skewed casing treatment. The bend skewed casing treatment with porosity of 33% was selected for the present experimental study. The bend skewed casing treatment has slot width equal to the maximum thickness of the rotor blade. The casing treatment geometry has an axial front segment and a 45° staggered rear segment following the blade tip stagger. Both the segments were skewed by 45° in the radial plane, in such a way that the flow emerging from the casing slots would do so with swirl contrary to the direction of rotor rotation. The plenum chamber which can also be called as stagnation zone exists above the skewed slots. The plenum chamber has an axial length equal to the axial length of the casing treatment slots. The maximum depth of the plenum chamber was 11 mm and which was equal to the depth of bend skewed casing slots. The depth of plenum chamber was varied from zero, half the slot depth, and equal to slot depth in order to get variable volume. The porosity and axial location of the casing treatment relative to the rotor tip chord were chosen from the earlier experimental programs on effect of bend skewed casing treatment porosities and axial coverages for the present compressor stage. Optimum performance of the transonic compressor stage was obtained at 20% and 40% axial coverages and for 33% porosity configurations. The axial coverages of 20% and 40% were chosen for the present study to understand the effects of plenum chamber volume on the performance of single stage transonic axial flow compressor. The performance of the compressor stage with solid casing and casing treatment with different plenum volume was obtained and compared at different operating speeds. The compressor performance was derived for the fixed casing treatment porosity of 33% and for three different configurations of plenum chamber volumes at two different axial coverages. Experimental investigations reveal that the plenum chamber volume does have an impact on the stable operating range of the compressor. The compressor stall margin improves with increase in the plenum chamber volume. Bend skewed casing treatment coupled with plenum chamber of depths equal to the slots depth results in maximum stall margin improvement of 37.62% as compared to 26.40% without plenum chamber over the solid casing at 40% axial coverage. For this combination 0.8% improvement in the peak stage efficiency above the solid casing was noticed at 60% design speed.

scholarly journals Effect of the Rear Stage Casing Treatment on the Overall Performance of a Multistage Axial-Flow Compressor

1982 ◽  
Author(s):  
Yao-Lin Gao ◽  
Ke-Ming Li
Keyword(s):  
High Speed ◽  
Axial Flow ◽  
Rotor Blades ◽  
Stall Margin ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Surge Margin ◽  
Engine Compressor ◽  
Overall Performance ◽  
Flow Compressor

This paper discusses the effect of tip treatment in the rear stages of a compressor on the high speed stall margin and efficiency. A nine stage engine compressor was tested in a rig with and without casing treatment on the tip sections of the last three rotors. Another series of tests were conducted on a modified compressor with twisted rotor blades in the rear stages. For both compressors, tip treatment improved high speed surge margin. The first compressor encountered no loss of efficiency with the addition of tip treatment, but the second compressor suffered a loss of efficiency.

Performance Characterization of the Effect of Axial Positioning of Bend Skewed Casing Treatment Retrofitted to a Transonic Axial Flow Compressor

2014 ◽  
Author(s):  
Dilipkumar B. Alone ◽  
Subramani Satish Kumar ◽  
Shobhavathy Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A. M. Pradeep ◽  
...  
Keyword(s):  
Axial Flow ◽  
Single Stage ◽  
Compressor Stage ◽  
Stall Margin ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Transonic Compressor ◽  
Maximum Improvement ◽  
Flow Compressor ◽  
Stage Efficiency

The performance of an aero-engines to a large extend depends on the performance behavior of axial flow compressors and is restricted by the compressor instabilities like rotating stall and surge. In the present study, attempts have been made to design and develop the bend skewed casing treatment geometries with lower porosities to improve the stable operating range of single stage axial flow compressor. Experimental investigations were undertaken to study the impact of axial position of one of the casing treatment geometry on the single stage transonic axial flow compressor. The transonic compressor used for the current experimental studies has a stage total to total pressure ratio of 1.35, corrected mass flow rate of 22 kg/s at an operating speed of 12930 rpm. The compressor stage steady and unsteady state response for 20%, 40%, 60% and 100% axial chord coverage relative to the rotor tip chord of the bend skewed casing treatment with a porosity of 33% was studied experimentally. The objective was to identify the optimum axial location; which will give maximum improvement in the stall margin with minimal loss of compressor stage efficiency. Through an experimental study it was observed that the axial location of bend skewed casing treatment plays a very crucial role in governing the performance of the transonic compressor. For all the investigated axial coverages, compressor stall margin increases but the optimum performance in terms of stall margin improvement and efficiency gains were observed at 20% and 40% of the rotor chord. This trend shows good agreement with existing published literature. An improvement of 31.7% in the stall margin with an increase in the stage efficiency was obtained at one of the axial coverage. Maximum improvement of 37% in the stall margin above the solid casing was noticed at 60% axial coverage. The stalling characteristics of the compressor stage also changes with the axial positions. In the presence of solid casing the nature of stall was abrupt and stalls cells travels at half the rotor speed. The blade element performance also studied at the rotor exit using pre-calibrated aerodynamic probe.

Some Blade Designs for an Axial Flow Compressor Stage

1954 ◽  
Vol 58 (517) ◽  
pp. 61-64
Author(s):  
R. G. Taylor
Keyword(s):  
Mach Number ◽  
Axial Flow ◽  
Compressor Stage ◽  
Axial Flow Compressor ◽  
Design Specifications ◽  
Reaction Condition ◽  
Forced Vortex ◽  
Vortex Solutions ◽  
Flow Compressor ◽  
Constant Mach Number

Two design conditions for an axial flow compressor stage are proposed and examined. These are, the constant reaction condition (incorporating I “ radial equilibrium ”), and the condition that the Mach number at inlet to the rotor shall be invariant with radius. In addition, the combination of these two properties in one stage is considered. It is found, with further assumptions regarding the nature of the flow, that a forced vortex type of flow will satisfy both design specifications. The forced vortex solutions for the various cases are presented, and for constant Mach number at inlet to the rotor, more general solutions are given.

Effects of Endwall Profiling on Axial Flow Compressor Stage

2009 ◽  
Author(s):  
Jialing Lu ◽  
Wuli Chu ◽  
Yanhui Wu
Keyword(s):  
Flow Field ◽  
Engineering Design ◽  
Axial Flow ◽  
Design Tool ◽  
Operating Conditions ◽  
Compressor Stage ◽  
Corner Separation ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Stage Efficiency

In recent years endwall profiling has been well validated as a major new engineering design tool for the reduction of secondary loss in turbines. However, its application on compressors have been rarely performed and reported. This paper documents the findings of the analysis for diminishing compressor stator corner separation using endwall profiling; In the study, novel profiled endwalls were designed and numerically studied on a subsonic axial-flow compressor stage. The compressor stator endwalls were profiled on both axial and azimuthal directions. The results showed, the stator corner separation was significantly suppressed under all the operating conditions by implementing this profiled endwall. Significant improvements on stage pressure ratios and stage efficiency were observed. Detailed flow field changes, as well as endwall profiling methods are provided in the paper, so that the results of this research can be referenced to other compressor designs.

Stall cell blockage in a high-speed multistage axial-flow compressor

1990 ◽  
Author(s):  
STEVEN GORRELL ◽  
WILLIAM COPENHAVER ◽  
WALTER O'BRIEN
Keyword(s):  
High Speed ◽  
Axial Flow ◽  
Axial Flow Compressor ◽  
Flow Compressor

Numerical Investigations of the Coupled Flow Through a Subsonic Compressor Rotor and Axial Skewed Slot

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Xingen Lu ◽  
Wuli Chu ◽  
Junqiang Zhu ◽  
Yangfeng Zhang
Keyword(s):  
Axial Flow ◽  
Tip Clearance ◽  
Stall Margin ◽  
Tip Clearance Flow ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Compressor Rotor ◽  
Clearance Flow ◽  
Flow Through ◽  
Flow Compressor

In order to advance the understanding of the fundamental mechanisms of axial skewed slot casing treatment and their effects on the subsonic axial-flow compressor flow field, the coupled unsteady flow through a subsonic compressor rotor and the axial skewed slot was simulated with a state-of-the-art multiblock flow solver. The computational results were first compared with available measured data, that showed the numerical procedure calculates the overall effect of the axial skewed slot correctly. Then, the numerically obtained flow fields were interrogated to identify the physical mechanism responsible for improvement in stall margin of a modern subsonic axial-flow compressor rotor due to the discrete skewed slots. It was found that the axial skewed slot casing treatment can increase the stall margin of subsonic compressor by repositioning of the tip clearance flow trajectory further toward the trailing of the blade passage and retarding the movement of the incoming∕tip clearance flow interface toward the rotor leading edge plane.

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