Effect of casing aspiration on the tip leakage flow in the axial flow compressor cascade

Abstract

Tip leakage flow is usually responsible for the deterioration of compressor performance and stability. The current paper conducts numerical simulations on the impact of casing aspiration on the axial compressor cascade performance. Three aspiration schemes with different chordwise coverage are studied and analyzed. It is found that the cascade performance can be effectively improved by the appropriate casing aspiration, and the optimum aspiration scheme should cover the area including the onset point of tip leakage vortex and its vicinity. The control mechanisms are different for the aspiration schemes located at different blade chord ranges. For the aspiration scheme covering the onset point of tip leakage vortex, the improvement of the cascade performance is mainly due to that the starting point of the tip leakage vortex is shifted downstream. The original tip leakage vortex structure is divided into two parts if the aspiration scheme is located behind the onset point of tip leakage vortex and the final control effect is the combination of the influence from the two different parts of tip leakage vortex. Additionally, the casing aspiration redistributes the blade loading along the chord near blade tip. The results of these investigations may offer guidance for the appropriate design of aspiration scheme in the future updated compressors and the overall total pressure loss coefficient caused by aspiration slot should be considered in the design process.

Control and Entropy Analysis of Tip Leakage Flow for Compressor Cascade under Different Clearance Sizes with Endwall Suction

“…The central difference method and the fourth-order Runge–Kutta iterative method are used to discretize the space and time terms of the control equations. According to the previous research experience of our research group [ 18 , 19 ], the one-equation S-A turbulence model has the better convergence and stability than the other two equation models, and it is also found that this turbulence model can accurately predict the flow in the cascade, compared with the experimental results. Therefore, the S-A turbulence model is selected to simulate the internal turbulence in current research.…”

“…In recent years, this technique has also been used to control the TLF in the clearance, and it can be divided into two categories according to different aspiration positions: one is the blade tip suction (BTS) and the other is the endwall suction (ES). Mao et al [ 18 , 19 ] studied the influence of the axial position of the suction slot on the TLF of the compressor cascade controlled by the BTS and ES respectively. The results showed that both aspiration schemes could effectively reduce the TLF intensity and flow loss of the compressor cascade.…”

Control and Entropy Analysis of Corner Flow Separation in a Compressor Cascade Using Streamwise Grooves

“…The calculation results are dependent on the chosen software, turbulence models, and solver settings. The CFD code used in this study was the Numeca Fine/Turbo solver, which has been widely used in many academic institutes and industry companies [ 37 , 38 ]. The steady Reynolds-averaged Navier–Stokes equation was carried out in the present paper.…”

Numerical Research on the Impact of Axial Position of Endwall Suction Slot on Tip Leakage Flow

“…The results showed that the flow control effect was the best when the suction slot was positioned directly above the blade tip, and the flow control effect increased with the increase of suction flow rate (SFR, defined as the ratio of the suction mass flow rate to the inlet mass flow rate.). Some scholars have also studied the flow control of the TLF by slotting or grooving suction on the rotor casing and had a better understanding of the mechanism of BLS to suppress the TLF and TLV (Gümmer et al 2008;Lu et al 2017a;Perry et al 2017;Mao et al 2017Mao et al , 2018b.…”