Windage measurements for rotating disc with protrusions
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摘要: 为研究壁面不同粗糙程度以及带有螺栓等表面凸起的转盘风阻扭矩特性,建立了一个转盘扭矩测量实验台.自由盘测量结果与经典经验关系式较好的符合度验证了测量方法的准确性.分析研究了在不同粗糙度以及附有6种凸起结构的转盘风阻扭矩规律.结果表明,壁面的粗糙会增大转盘受到的扭矩,在所测量旋转雷诺数范围内,从气动光滑一直到粗糙高度0.2 mm,扭矩系数增大1倍.基于气动光滑自由盘经验关系式进一步总结出相对粗糙度对于风阻扭矩的影响系数.对比6种凸起引起的风阻扭矩特性发现,叶型凸起会大幅降低风阻扭矩.凸起安装迎风角度的改变会带来10%的风阻扭矩差别.结合自由光滑盘扭矩系数经验关系式,总结出不同凸起形状对于扭矩系数的影响因数.Abstract: A new test rig was performed to investigate the windage torque of the rotating disc with protrusions or roughness on the rotor surface. The new measurement method was verified accurately with the comparison between the free disc data and the correction in open literatures. Six configurations of protrusion were carried out. The results show that the moment coefficient of rotor increases with increasing the disc surface roughness. The increasing roughness from hydrodynamically smooth to a roughness ratio of 1 120(corresponding to a roughness height of 0.2 mm) causes a double torque value of rotor within the test range. The impact factors obtained from hydrodynamically smooth disc case were derived for the roughness disc cases. The blade shape protrusion caused the smallest friction torque of the rotor within the six configurations. Changing the protrusions orientation with respect to the direction of the fluid causes the moment coefficient a difference of approximately 10 percents. New correlations were proposed for the windage torque for the hydrodynamically smooth and the roughness rotor cases and the rotor with protrusions respectively.
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Key words:
- rotating disc /
- roughness /
- windage loss /
- friction torque /
- protrusions
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[1] Von Kármán T. Technical memorandum on laminar and turbulent friction[R].National Advisory Committee for Aeronautics,No.092,1921 [2] Theodorsen T, Regier A.Experiments on drag of revolving discs, cylinders and streamline rods at high speeds[R].NACA-TR-793,1944 [3] Bayley F J, Owen J M.Flow between a rotating and stationary disc[J].Aeronautical Quarterly,1969,20(4):333-354 [4] Dorfman L A. Hydrodynamic resistance and the heat loss of rotating solids[M].Edinburgh:Oliver & Boyd,1963 [5] Nece R E, Daily J M.Roughness effects on frictional resisitance of enclosed rotating disks[J].ASME Journal of Basic Engineering,1960,82(3):553-560 [6] Daniel W A, Johnson B V,Graber D J.Aerodynamic and torque characteristics of enclosed Co/counter-rotating discs[J]. Journal of Turbomachinery,1991,113(1):67-74 [7] Pett A D W, Coren D D,Childs P R N.Model validation for a shrouded rotor-stator system with superposed cooling and static protuberances[C]//Proceedings of the ASME Turbo Expo 2007.Montreal:ASME,2007,6 PART B:1379-1386 [8] Coren D. Windage due to protrusions in rotor-stator systems[D].Brighton:University of Sussex,2008 [9] Coren D, Childs P R N,Long C A.Windage sources in smooth-walled rotating disc systems[J].Proceedings of the Institution of Mechanical Engineers,Part C:Journal of Mechanical Engineering Science,2009,223(4):873-888 [10] Millward J A, Robinson P H.Experimental investigation into the effects of rotating and static bolts on both windage heating and local heat transfer coefficients in a rotor/stator cavity[C]//American Society of Mechanical Engineers.New York:ASME,1989:GT196 [11] Miles A L. An experimental study of windage due to rotating and static bolts in an enclosed rotor-stator system[D].Brighton:University of Sussex,2012 [12] Moghaddam E R, Long C,Sayma A.A numerical investigation of moment coefficient and flow structure in a rotor-stator cavity with rotor-mounted bolts[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2013,227(3):306-327 [13] 张达,韩建桥,罗翔,等. 中心进气转静系转盘风阻扭矩数值模拟[J].航空动力学报,2014,29(4):755-762 Zhang Da,Han Jianqiao,Luo Xiang,et al.Numerical simulation of friction torque of rotating disc forrotor-stator system with central inflow[J].Journal of Aerospace Power,2014,29(4): 755- 762(in Chinese) [14] Luo X, Zhang D,Tao Z,et al.Windage measurements in a rotor-stator system with superimposed cooling and rotor-mounted protrusions[J].Journal of Engineering for Gas Turbines and Power,2014,136(4):042505 [15] Tao Z, Zhang D,Luo X,et al.Windage heating in a shrouded rotor-stator system[J].Journal of Engineering for Gas Turbines and Power,2014,136(6):062602 [16] Nikuradse J. Laws of flow in rough pipes[M].Washington:National Advisory Committee for Aeronautics,1950
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