Numerical and experimental investigation into clearance leakage flow and aerodynamic performance for a fully shrouded turbine cascade
Shroud is widely used in turbines to eliminate the tip leakage flow.This paper investigates effects of full shroud on clearance leakage,different types of secondary flows and interaction with one another.Experimental measurements were undertaken in a linear turbine cascade fitted in a low speed wind tunnel.Blades with a turning angle of 108° were applied.Two different upper casings were used,one being flat and the other with a cavity.Secondary structure,distribution of flow angles and total pressure loss on exit planes were measured for each case.Experimental and numerical results show that compared with the unshrouded blades,the shroud reduces aerodynamic loss due to elimination of tip leakage.By comparing the two shrouded cascades with each other,it shows that the cascade with a grooved casing has smaller over-shroud leakage due to energy dissipation occurred in the cavity.This demonstrates the need of sealing over the shroud.Results also show that variation of angles of incidence influences three-dimensional vortex structures and their intensity in blade passages.Change of incidence angles also affects static pressure distribution on the suction surface of the blade.Positive angles of incidence help improve flow field and thus improves aerodynamics performance for the current blades with large turning angles.
Turbine cascade Clearance leakage flow Shrouded turbine blade RANS Secondary flow
Yan Liu Peng-fei Zhao Pan-nian Liu Wo-han Jiang Hua-wei Lu
School of Energy and Power Engineering,Dalian University of Technology,Dalian,China,116024 Marine Engineering College,Dalian Maritime University,Dalian,China,116024
国际会议
The 5th International Symposium on Jet Propulsion and Power Engineering(第五届喷气推进与动力工程国际会议)
北京
英文
1-8
2014-09-15（万方平台首次上网日期，不代表论文的发表时间）