Axial Flow Compressor Design Optimization: Part II—Throughflow Analysis

1990 ◽  
Vol 112 (3) ◽  
pp. 405-410 ◽  
Author(s):  
A. Massardo ◽  
A. Satta ◽  
M. Marini

A new technique is presented for the design optimization of an axial-flow compressor stage. The procedure allows for optimization of the complete radial distribution of the geometry, since the variables chosen to represent the three-dimensional geometry of the stage are coefficients of suitable polynomials. Evaluation of the objective function is obtained with a throughflow calculation, which has acceptable speed and stability qualities. Some examples are given of the possibility to use the procedure both for redesign and, together with what was presented in Part I, for the complete design of axial-flow compressor stages.

Author(s):  
Aristide Massardo ◽  
Antonio Satta ◽  
Martino Marini

A new technique is presented for the design optimization of an axial-flow compressor stage. The procedure allows for optimization of the complete radial distribution of the geometry since the variables, chosen to represent the three dimensional geometry of the stage, are coefficients of suitable polynomials. Evaluation of the objective function is obtained with a through-flow type calculation, which has acceptable speed and stability qualities. Some examples are given of the possibility to use the procedure both for redesign and, together with what was presented in Part I, for the complete design of axial-flow compressor stages.


1954 ◽  
Vol 58 (517) ◽  
pp. 61-64
Author(s):  
R. G. Taylor

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.


Author(s):  
Jialing Lu ◽  
Wuli Chu ◽  
Yanhui Wu

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.


1992 ◽  
Vol 114 (3) ◽  
pp. 675-685 ◽  
Author(s):  
A. Goto

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 hotwire 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 span-wise 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.


1953 ◽  
Vol 57 (511) ◽  
pp. 463-463
Author(s):  
R. G. Taylor

In Mr. J. M. Stephenson's Technical Note, “ The Elimination of Wall Effects in Axial-Flow Compressor Stages,” in the April 1953 issue of the Journal, the author suggests that the blade rows of an axial flow compressor are so closely spaced as to ensure that the axial velocity profile is unchanged across the rows. Whether this statement is correct or not such an assumption regarding the axial velocity profile is a basic design condition and when made it will not leave any flexibility in the choice of the function f(r).


Author(s):  
Dilipkumar B. Alone ◽  
Subramani Satish Kumar ◽  
Shobhavathy Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A. M. Pradeep ◽  
...  

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.


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