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北京航空航天大学流体力学研究所高琪副教授来院作学术报告

发布日期:2016-11-30

北京航空航天大学流体力学研究所副所长高琪学术报告:

非细长三角翼涡破裂的三维流场可视化和PIV测速

 

报告主题:非细长三角翼涡破裂的三维流场可视化和PIV测速

报告时间:2016年12月1日(本周四)上午10点

报告地点:苏州大学北校区工科楼1207(生物制造中心会议室)

报告人简介:

高琪,北京航空航天大学航空学院副教授,流体力学研究所副所长,2001年在浙江大学获学士学位,2005年在清华大学获硕士学位,2011年在美国明尼苏达大学获博士学位。他的研究领域是实验流体力学,目前的研究主要关注流场测速的新技术及其应用,还包括湍流边界层、心血管系统流动以及流动控制。

 

Gao, Qi

Associate Professor

Vice Director, Institute of Fluid Mechanics

Beijing University of Aeronautics and Astronautics

Beijing, China, 100191

E-mail: qigao@buaa.edu.cn

 

Dr. Gao got his Bachelor's degree in the Zhejiang University in 2001, Master degree in the Tsinghua University in 2005 and Ph.D degree in the University of Minnesota in 2011. He was an Assistant Professor in the Institute of Fluid Mechanics at Beijing University of Aeronautics and Astronautics from 2011 to 2013. He has been promoted to an Associate Professor in 2013. Dr. Gao's research is broadly in the area of experimental fluid mechanics. Current projects focus on developing techniques of volumetric velocimetry and their applications. Studies on turbulent boundary layers, cardiovascular flows and flow control are highly interested.

3D flow visualization and tomographic particle image velocimetry for vortex breakdown over a non-slender delta wing

Volumetric measurement for the leading-edge vortex (LEV) breakdown of a delta wing has been conducted by three-dimensional (3D) flow visualization and tomographic particle image velocimetry (TPIV). The 3D flow visualization is employed to show the vortex structures, which was recorded by four cameras with high resolution. 3D dye streaklines of the visualization are reconstructed using a similar way of particle reconstruction in TPIV. Tomographic PIV is carried out at the same time using same cameras with the dye visualization. Q criterion is employed to identify the LEV. Results of tomographic PIV agree well with the reconstructed 3D dye streaklines, which proves the validity of the measurements. The time-averaged flow field based on TPIV is shown and described by sections of velocity and streamwise vorticity. Combining the two measurement methods sheds light on the complex structures of both bubble type and spiral type of breakdown. The breakdown position is recognized by investigating both the streaklines and TPIV velocity fields. Proper orthogonal decomposition is applied to extract a pair of conjugated helical instability modes from TPIV data. Therefore, the dominant frequency of the instability modes is obtained from the corresponding POD coefficients of the modes based on wavelet transform analysis.