A Model for Concentrated Vortices and an Unsteady Wake Model for Turbine
The flow in aero-engine is inherently unsteady due to the relative motion between rotor and stator blade rows. In many cases, the effect of rotor-stator interaction is too important to be neglected. As one of the most important sources of unsteady flow in aero-engine, wake-related issues have interested many investigators. In this work, effort is devoted to construct an unsteady wake model for turbine, which considers the small-scale fluctuation caused by vortices shedding from blades trailing edge. Results from large eddy simulation (LES) are analyzed. In the wake, the vortex-induced velocity fluctuation exhibits strong self-similarity as the induced velocity distribution of concentrated vortex, and according to this result, the classical Lamb-Oseen concentrated vortex model is modified. The modified Lamb-Oseen vortex model shows better agreement with the behavior of vortices contained in the vortex street. The transient velocity field can be viewed as sum of a time-averaged field and a fluctuation field which shows much respect to the modified Lamb-Oseen vortex model. And traditional time-averaged velocity field is coincided with Gaussian distributioa A twodimensional unsteady wake model was built based on the numerical results of this paper.
concentrated vortex wake model unsteady Lamb-Oseen vortex Vortex Street stator/rotor interaction turbine
WEI Zuo-jun QIAO Wei-yang ZHAO Lei SHI Pei-jie
School of Power and Energy, Northwestern Polytechnical University, Xian, China
国际会议
4th International Symposium on Jet Propulsion and Power Engineering(第四届喷气推进与动力工程国际会议 ISJPPE2012)
西安
英文
51-59
2012-09-10（万方平台首次上网日期，不代表论文的发表时间）