scholarly journals The Numerical Simulation of a High-Speed Axial Flow Compressor

Author(s):  
Richard A. Mulac ◽  
John J. Adamczyk

The advancement of high-speed axial flow multistage compressors is impeded by a lack of detailed flow field information. Recent developments in compressor flow modeling and numerical simulation have the potential to provide needed information in a timely manner. This paper, which consists of two parts, will explore this topic. The first part will address the development of a computer program to solve the viscous form of the average-passage equation system for multistage turbomachinery. Programming issues such as in-core versus out-of-core data storage and CPU utilization (parallelization, vectorization, and chaining) will be addressed. Code performance will be evaluated through the simulation of the first four stages of a five stage, high-speed, axial flow compressor on a CRAY Y-MP8/8128 computer. The second part will address the flow physics which can be obtained from the numerical simulation. In particular, an examination of the endwall flow structure will be made, and its impact on blockage distribution assessed.

1992 ◽  
Vol 114 (3) ◽  
pp. 517-527 ◽  
Author(s):  
R. A. Mulac ◽  
J. J. Adamczyk

The advancement of high-speed axial flow multistage compressors is impeded by a lack of detailed flow field information. Recent developments in compressor flow modeling and numerical simulation have the potential to provide needed information in a timely manner. This paper, which consists of two parts, will explore this topic. The first part will address the development of a computer program to solve the viscous form of the average-passage equation system for multistage turbomachinery. Programming issues such as in-core versus out-of-core data storage and CPU utilization (parallelization, vectorization, and chaining) will be addressed. Code performance will be evaluated through the simulation of the first four stages of a five-stage, high-speed, axial flow compressor on a CRAY Y-MP8/8128 computer. The second part will address the flow physics, which can be obtained from the numerical simulation. In particular, an examination of the end-wall flow structure will be made, and its impact on blockage distribution assessed.


1997 ◽  
Vol 119 (4) ◽  
pp. 985-994 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana ◽  
J. Prato ◽  
J. R. Fagan

The results from measurements of the unsteady total pressure field downstream of an embedded stage of a three stage axial flow compressor are presented in this paper. The measurements include area traverses of a high response kulite total pressure probe and a pneumatic five hole probe downstream of stator 2 at the peak efficiency operating point for the compressor. These data indicate that both the shaft-resolved and unresolved fluctuations contribute to the unsteadiness of the total pressure field in multistage compressors. Specifically, regions associated with high levels of unsteadiness and, consequently, high levels of mixing including both the hub and casing end walls and the airfoil wakes have significant levels of shaft resolved and unresolved unsteadiness. Temporal variations of stator exit flow are influenced by both shaft resolved and unresolved unsteadiness distributions. The limitations of state-of-the-art instrumentation for making measurements in moderate and high speed turbomachinery and the decomposition used to analyze these data are also discussed.


1989 ◽  
Vol 111 (4) ◽  
pp. 418-425 ◽  
Author(s):  
G. L. Giannissis ◽  
A. B. McKenzie ◽  
R. L. Elder

This paper reports on an examination of rotating stall in a low-speed three-stage axial flow compressor operating with various degrees of stage mismatch. The objective of this study was to simulate the mismatching that occurs in high-speed multistage compressors when operating near surge. The study of the stall zones involved the use of fast response measurement techniques. The study clearly shows how stages can operate in an axisymmetric fashion even when heavily stalled, since rotating stall inception requires the stall of more than one stage. The study also compares conditions required for full-span and part-span stall and suggests that the part-span stall structure is more relevant to high-speed multistage compressors.


1990 ◽  
Author(s):  
STEVEN GORRELL ◽  
WILLIAM COPENHAVER ◽  
WALTER O'BRIEN

Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana ◽  
J. Prato

The results from the area traverse measurements of the unsteady velocity and total temperature downstream of the second stator of a three stage axial flow compressor have been correlated to derive various deterministic stress and heat-flux terms. These terms are consistent with those arising from the average-passage equation system of Adamczyk (1985). The deterministic periodic stress and heat-flux terms were found to be larger than the aperiodic terms for both the normal and shear components. Consequently the terms involving the aperiodic components in the average-passage equations could be neglected for stator exit and rotor inlet flow modeling. The deterministic periodic normal and shear stresses were seen to be most significant in the stator wakes away from the endwall regions. The most significant shear stress correlation was between the axial and tangential velocity components. Since the correlations involving the radial component were small, it is postulated that the dominant mechanism for mixing (in the radial direction) is due to the steady deterministic radial velocity. All three components of deterministic heat-flux were found to be significant in this flow field especially in the wakes. The dominant terms in the average-passage equation system away from the endwalls were due to the tangential gradient compared to the radial gradient terms and both the terms were found to be of equal importance in the hub and casing endwall regions.


1959 ◽  
Vol 81 (3) ◽  
pp. 259-264 ◽  
Author(s):  
A. L. London

The prime-mover combination of piston-and-cylinder components with a high-speed exhaust-gas turbine and, in some cases, a centrifugal or axial-flow compressor has assumed a variety of forms. Progress in the development of some of the more notable members of this family of compound engines is presented.


Author(s):  
Takashi Goto ◽  
Tetsuya Oshio ◽  
Naoki Tani ◽  
Mizuho Aotsuka ◽  
Guillaume Pallot ◽  
...  

Abstract Despite significant advancements in computational power and various numerical modeling in past decades, flow simulation of a multi-stage axial-flow compressor is still one of the most active areas of research, for it is the critical component in engine performance and operability, and there are so many elements that need to be looked into to predicting correct matching of the stages and accurate flow distribution inside the machine. Modeling unsteadiness, both deterministic and random types, and real geometries are among the most important features to be considered in such prediction. The authors have conducted in their previous studies a series of unsteady RANS (URANS) simulations of a 6.5-stage high-speed highly-loaded axial-flow compressor, and explored many unsteady effects as well as effects of real geometries such as Variable Stator Vane (VSV) clearance and inter-stage seal leakage flow on the compressor performance. However, all the analyses failed to predict correct stage matching, total pressure and temperature radial profiles, or mass-flow with adequate accuracies. In the present study, an Improved Delayed Detached Eddy Simulation (IDDES) with SST k-omega model is applied to the simulation of the same compressor configuration at aerodynamic design point. Fifth-order WENO scheme is employed for improved spatial accuracy to suppress significant increase in mesh size. Total number of mesh points are over 400 million for 1/10th sector model. Computations are ensemble averaged for 20 sector passage. Computed overall performance and flow field are compared with the compressor rig test data. The predictions of inter-stage total temperature radial profiles are noticeably improved over the URANS with the same mesh, discretization scheme and eddy turbulence model. Good comparison with the rig data indicates the current simulation is properly capturing the span-wise mixing phenomena. Unsteady flow field are compared between IDDES and URANS to locate the cause for the enhanced mixing. It is shown that components of Reynolds stress responsible for radial diffusion and anisotropic features are intensified in the tip leakage vortex at the rotor exit for the IDDES.


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