航空学院青年学术论坛第一〇三讲

发布日期:2018年05月14日      点击:次  |   审核:航空学院

John A. Ekaterinaris教授高阶CFD算法全英文短期课程、讲座通知

应航空学院“飞行器复杂流动与控制学科创新引智基地”邀请,美国安柏瑞德航空航天大学(Embry-Riddle Aeronautical University)航天工程系杰出教授John A. Ekaterinaris将于2018年5月19日至6月2日来我校从事教学和研究工作,期间将作两次学术报告、并讲授10学时的“高阶CFD算法”全英文短期课程,欢迎广大研究生和高年级本科生报名选修(旁听)学习。

John A. Ekaterinaris简历:

John A. Ekaterinaris:现任美国安柏瑞德航空航天大学(Embry-Riddle Aeronautical University)航天工程系杰出教授。教授1982年于佐治亚理工学院获航天工程专业博士学位,于1987-1995年在NASA–Ames中心从事研究,并同时在Naval Postgraduate School任教;于1995-1997年在丹麦RISOE国家实验室任高级研究科学家,于1997-2000年任职于加州Nielsen工程研究中心;2000-2005年在FORTH/IACM任研究主任,2005-2012年在希腊University of Patras任教。

Ekaterinaris教授的主要研究方向包括:计算流体力学(应用于空气动力学、磁流体力学、气动声学、湍流、流固耦合、生物力学等),高阶高精度数值算法、多尺度流等。Ekaterinaris教授已发表期刊论文60余篇,引用达2000余次。

Ekaterinaris教授目前担任Journal Progress in Aerospace Science副主编,Journal of Aerospace Science and Technology主编。

John A. Ekaterinaris: currently distinguisshed professor in the Department of Aerospace Engineering of Embry-Riddle Aeronautical University. He received his B.S. in Electrical and Mechanical Engineering from the Aristotle University of Thessaloniki in Greece in Oct. 1977. Started graduate studies in the US in 1981 and revived his M.Sc. in Mechanical Engineering in 1982 and his Ph.D. from the School of Aerospace Engineering in 1987, both at the Georgia Institute of Technology.

Between 1987 – 1995, worked at NASA–Ames Research Center at Moffett Field CA, and at the same timehewas faculty at the Naval Postgraduate Scholl at Monterey CA. He took a Senior Research Scientist position at RISOE National Laboratory in Denmark between 1995 – 1997 where he worked on wind energy, he returned to CA and worked at Nielsen Engineering and Research (NEAR) between 1997 – 2000.

In Oct. 2000 he took the Research Director position at FORTH/IACM, where he remained until 2005. In Sept. 2005 he joined the faculty of Mechanical and Aerospace Engineering at the University of Patras. He joined the faculty of Embry-Riddle Aeronautical University in August 2012 where he is currently teaching and performing research.

His interests are computational mechanics (including aerodynamics, magnetogasdynamics, electromagnetics, aeroacoustics, flow transition, turbulence research, and flow structure interaction), high order methods for PDEs, multiscale phenomena, stochastic PDE’s, and biomechanics. He is author of over 60 journal papers. He has been member American Institute of Aeronautics and Astronautics (AIAA), where he served as member at the Flight Mechanics and Fluid Dynamics Technical Committees, and AIAA associate fellow of since 1985.

He performed funded research in the US and in Europe with the European Space Agency (ESA), and through the EU framework programs. He also performed funded research thought the offices of AFOSR and ARO. He is associate editor of the Journal Progress in Aerospace Science (JPAS) and editor in chief of the Journal Aerospace Science and Technology (AESCTE).

Seminar 1:521日,上午9:00-10:00,航空楼A706

Attenuation of a shock save propagating in ducts with grooves and the wave patterns following it

Experimental investigations and numerical simulations of a shock wave propagation inside ducts with roughness is presented. The roughness is added in the form of grooves. Different shapes are considered in order to better understand the physics behind the evolution of the complex wave patterns resulting from diffraction and reflection of the primary moving shock. The contribution of these phenomena to pressure attenuation is investigated. The numerical method is validated through several test cases, and the results are compared against the theory and the experimental measurements. Excellent agreement between high resolution computations and the experiment is obtained for the shock speeds and complex wave patterns created by the grooves. Time history of pressure at various locations, and shock strengths are compared with the measurements. It is found that accurate pressure prediction requires a close representation of the full experimental setup to fully capture boundary layer development, and pressure losses associated with unsteady moving shocks in long ducts. Different groove geometry has been tested in the numerical simulation in order to identify the shape that will diminish shock strength. Analysis and animations of the computed results are used to reveal salient features of the complex unsteady flow field.

Seminar 2:522日,上午10:00-11:00,航空楼A706

On the use of high order shock capturing numerical schemes for linear and nonlinear wave propagation

Developments of high order accurate numerical schemes for the numerical solutions of the linearized Euler equations that describe adequately sound propagation have been pursued for a number of years. These were finite difference methods suitable for domains with moderate complexity. More recently, the discontinuous Galerkin finite method, which is a low dissipative upwind method for sufficiently high order of accuracy, has been employed to make possible aeroacustic predictions in complex domains. The unique p-adaptive capabilities of the DG method and the low diffusion it has with higher order of approximations make it suitable for electromagnetic wave propagation and examples of p-adaptive strategies are shown for three-dimensional, large scale electromagnetic wave propagation problems. The linearized Euler equations describe however only propagation of aeroacoustic disturbances and for sound generation the full nonlinear problem must be considered. As a result, a number of high order upwind schemes and centered schemes with little added dissipation in the form of characteristic based or spectral filters have been employed for the numerical solution of the Navier-Stokes equations in direct and large eddy simulation of sound generation and propagation. For high speed flows, such as supersonic jets, discontinuities may develop and use of shock capturing schemes is necessary. For these class of aeroacoustic problems, weighted essentially non-oscillatory (WENO) schemes, discontinuous Galerkin discretization especially those providing high order shock capturing capability and even classical second order finite volume methods with high resolution meshes can be employed.

Outlines of the short course:

52324293031上午900-1130,友谊校区诚字楼315

1.Governing Equations for incompressible and compressible flow

2.Time marching methods for high order accurate spatial discretizations

3.Mathematical character and properties of the governing equations

4.Splitting schemes and implicit time marching methods

5.Explicit high-order accurate finite difference formulas

6.Compact finite difference methods

7.Applications of high order compact schemes

8.Essentially nonoscillatory (ENO) schemes

9.Weighted ENO (WENO) schemes

10.Application of WENO

11.High order Finite volume methods for structured meshes

12.High order methods for unstructured meshes

地址:陕西省西安市碑林区友谊西路127号

邮编:710072

联系:西北工业大学航空楼A319办公室

TEL:029-88493671  FAX:029-88493671

版权所有 西北工业大学航空学院 | http://hangkong.nwpu.edu.cn

空院微视野