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Multi-domain Spectral Immersed Interface Method for Solving Elliptic Equation with a Global Description of Discontinuous Functions

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Chinese Journal of Aeronautics 2012年第3期25卷 297-310页

作者： JIANG Yongsong LIANG An SUN Xiaofeng JING Xiaodong School of Jet Propulsion Beihang University Beijing 100191 China Department of Compressor Design Shenyang Aeroengine Research Institute Shenyang 110015 China AVIC Commercial Aircrafl Engine Co. Ltd. Shanghai 200241 China

This paper presents the extension of the global description approach of a discontinuous function, which is proposed in the previous paper, to a spectral domain decomposition method. This multi-domain spectral immersed interlace method（IIM） divides the whole computation domain into the smooth and discontinuous parts. Fewer points on the smooth domains are used via taking advantage of the high accuracy property of the spectral method, but more points on the discontinuous domains are employed to enhance the resolution of the calculation. Two that the domain decomposition technique can placed around the discontinuity. The present reached, in spite of the enlarged computational discontinuous problems are tested to verify the present method. The results show reduce the error of the spectral IIM, especially when more collocation points are method is t：avorable for the reason that the same level of the accuracy can be domain.

关键词： computational aerodynamics immersed interface method immersed boundary method Chebyshev spectral method domain decomposition method

Physical Body Impact After High Altitude Bail-out

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Chinese Journal of Aeronautics 2011年第2期24卷 145-149页

作者： CHEN Xiaopeng GUAN Huanwen ZHUO Congshan FENG Wenchun ZHONG Chengwen School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi'an 710072 China The First Aircraft Institute Aviation Industry Corporation of China Xi'an 710089 China School of Aeronautics Northwesern Polytechnical University Xi 'an 710072 China

In most of the emergency circumstances,the aircrew leaves the aircraft under unsatisfied conditions,such as too high relative velocity to the ambient air or low partial oxygen *** aircrew must pass through this area as quickly as possible before opening the parachute safely,viz.,*** simulations are conducted in this paper to explore the major characteris-tics of the aircrew free-fall process by using a commercial computational fluid dynamic（CFD） software,*** with the classical pressure-altitude and temperature-altitude relations,Navier-Stokes（N-S） equations for compressible flow are solved by using finite volume *** body velocity and the attitude are predicted with six-degree of freedom（6DOF） *** evolution of velocities,including horizontal,vertical components and angular velocity,is *** is also analyzed further according to the particle kinetic *** is validated that the theories can predict the process qualitatively well with a modi-fied drag effect,which mainly stems from the velocity *** empirical modification factor is proposed according to the fitting results.

关键词： computational aerodynamics free-fall six-degree of freedom parachute opening life-saving

A High Resolution Low Dissipation Hybrid Scheme for Compressible Flows

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Chinese Journal of Aeronautics 2011年第4期24卷 417-424页

作者： YU Jian YAN Chao JIANG Zhenhua School of Aeronautic Science and Engineering Beihang University Beijing 100191 China

In this paper, an efficient hybrid shock capturing scheme is proposed to obtain accurate results both in the smooth region and around discontinuities for compressible flows. The hybrid algorithm is based on a fifth-order weighted essentially non-oscillatory （WENO） scheme in the finite volume form to solve the smooth part of the flow field, which is coupled with a characteristic-based monotone upstream-centered scheme for conservation laws （MUSCL） to capture discontinuities. The hybrid scheme is intended to combine high resolution of MUSCL scheme and low dissipation of WENO scheme. The two ingredients in this hybrid scheme are switched with an indicator. Three typical indicators are chosen and compared. MUSCL and WENO are both shock capturing schemes making the choice of the indicator parameter less crucial. Several test cases are carried out to investigate hybrid scheme with different indicators in terms of accuracy and efficiency. Numerical results demonstrate that the hybrid scheme in the present work performs well in a broad range of problems.

关键词： computational aerodynamics hybrid scheme characteristic variables weighted essentially non-oscillatory scheme high resolution low dissipation