Studies of secondary flow at endwall of a supersonic compressor cascade

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 128-133 ◽  
Author(s):  
Denver J. Osborne ◽  
Wing F. Ng ◽  
Daniel L. Tweedt
2017 ◽  
Vol 31 (10) ◽  
pp. 4841-4852 ◽  
Author(s):  
Huaping Liu ◽  
Shuai Jiang ◽  
Yongchuan Yu ◽  
Dongfei Zhang ◽  
Huanlong Chen

Author(s):  
J. W. Kim ◽  
J. S. Lee ◽  
S. J. Song ◽  
T. Kim ◽  
H-. W. Shin

Experimental and numerical studies have been performed to investigate the effects of the leakage flow tangential velocity on the secondary flow and aerodynamic loss in an axial compressor cascade with a labyrinth seal. Six selected leakage flow tangential (vy/Uhub = 0.15, 0.25, 0.35, 0.45, 0.55 and 0.65) have been tested. In addition to the classical “secondary” flow, shroud trailing edge vortex and shroud leading edge vortex are examined. The overall loss decreases with increasing leakage flow tangential velocity. Increased leakage flow tangential velocity underturns the hub endwall flows through the blade passage, weakening the suction side hub corner separation. Due to the suction effect of the downstream cavity, increasing leakage flow tangential velocity weakens the shroud trailing edge vortex. Also, increasing leakage flow tangential velocity strengthens the shroud leading edge vortex, weakening the pressure side leg of the horseshoe vortex, and, in turn, the passage vortex. Thus, the overall loss is reduced with increasing leakage flow tangential velocity.


Author(s):  
Charlotte Hertel ◽  
Christoph Bode ◽  
Dragan Kožulović ◽  
Tim Schneider

An optimized subsonic compressor tandem cascade was investigated experimentally and numerically. Since the design aims at applications under incompressible flow conditions, a low inlet Mach number of 0.175 was used. The experiments were carried out at the low speed cascade wind tunnel at the Technische Universität Braunschweig. For the numerical simulations, the CFD-solver TRACE of DLR Cologne was used, together with a curvature corrected k-ω turbulence model and the γ-Reθ transition model. The aerodynamic loading was varied by incidence variation. Results are presented and discussed for different inlet angles: spanwise loss coefficient, turning, pressure rise coefficient and AVR together with contour plots of the wake plane, flow visualization and oil flow pictures. Experimental and numerical results were compared and found to be in good agreement. The secondary flow topology of the front blade is considerably altered by the aerodynamic loading variation, whereas the topology of the rear blade surface is almost unchanged. The effect of the nozzle between the tandem blades, was observable up to the end wall for all investigated incidences. In addition, a comparison is made to published results of previous experimental and numerical investigations of a transonic tandem compressor cascade [1] and its reference single compressor cascade [2]. The comparison of the tandem cascades revealed that the general structures of the secondary flow seem to be similar for similar loading.


Author(s):  
Huaping Liu ◽  
Deying Li ◽  
Bingxiao Lu ◽  
Menghan Yu

This paper presents a numerical investigation of secondary flow control in a high speed compressor cascade for different incoming flow incidences by means of endwall vortex generator jets (VGJs). The inlet Reynolds number is 560,000 in corresponding to an inlet Mach number of 0.67. Based on the detail analysis of the flow field and cascade performance, two effect mechanisms of the vortex induced by the VGJ are proposed. The first is to enhance the mixing between the endwall boundary layer and the mainstream. The second is to block the cross flow as an air obstacle. Therefore, the low energy fluids accumulation in the corner region could be decreased significantly, weakening the separation on the suction side and reducing the losses effectively. This benefit becomes more obvious with the increase of the incidence from i = −2° to 4°. Additionally, a more uniform flow angle as well as static pressure profile along the blade height is obtained at the cascade outlet. The maximum loss reduction is up to 12.9% while i = 4° with a jet mass flow ratio of 0.2%. However, the unfavorable impact of the VGJs is also detected in the up-washed region, where the loss is increased by the mixing processes between the mainstream fluids and the low energy fluids. For the case i = −4°, a strengthened induced vortex is generated due to the increased angle between the jet and incoming flow, resulting in loss increase in the up-washed region. Besides, a more rapid corner boundary layer development appears in the rear part of the passage, contributing to severe separation and loss enhancement, which suggests that the VGJ should be switched off for this incidence. Therefore, the advice to the application of the VGJ according the incidence is further obtained.


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