Effect of the Endwall Motion on a Hydrofoil with Various Widths of Clearance

28th IAHR symposium on Hydraulic Machinery and Systems

Guo, Q.^1,3 ; Zhou, L.J.^1,3 ; Wang, Z.W.^2 ; Xiao, R.F.^1,3 ; Yao, Z.F.^1,3

College of Water Resources and Civil Engineering, China Agricultural University, Beijing

100083, China^1

Department of Thermal Engineering, Tsinghua University, Beijing

100084, China^2

Beijing Eng. Research Center of Safety and Energy Saving Technology for Water Supply Network System, Beijing

100083, China^3

关键词: Leakage flow rate;    Lift and drag coefficients;    Loading characteristics;    Minimum pressure;    Relative motion;    Tip leakage vortex;    Tip separation vortices;    Velocity gradients;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/49/6/062021/pdf
DOI  :  10.1088/1755-1315/49/6/062021

来源: IOP

【 摘 要 】

This paper is devoted to evaluate the effects of the relative motion between the blade tip and casing wall with different widths of gap. The steady non-cavitating simulations around a sharp tip hydrofoil in tunnel with a moving endwall are implemented and another calculation with the stationary wall is carried out as a contrast. Overall, the endwall motion moves the trajectory of the tip leakage vortex (TLV) much closer to the foil but brings small effect on the streamwise vorticity and the minimum pressure in the TLV. The influence of the gap width is taken into account with the normalized gap width withinτ=0.02∼0.4. The flow features on a cross section inside the gap suggest that the endwall motion causes a little lower leakage flow rate and velocity in pitchwise direction. Inside a wider gap like τ=0.2, the pressure of the tip separation vortex (TSV) is a little higher and the direction of the velocity gradient for the streamwise flow is changed under the effect of the moving wall. The foil loading characteristics are revealed by the lift and drag coefficients which are a slightly lower under the effect of the endwall motion.