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A hybrid multidimensional Riemann solver to couple self-similar method with MULTV method for complex flows

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Chinese Journal of Aeronautics 2021年第7期34卷 29-38页

作者： Feng QU Di SUN Junjie FU Junqiang BAI School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Since proposed,the self-similarity variables based genuinely multidimensional Riemann solver is attracting more attentions due to its high resolution in multidimensional complex ***,it needs numerous logical operations in supersonic cases,which limit the method’s applicability in engineering problems *** order to overcome this defect,a hybrid multidimensional Riemann solver,called HMTHS(Hybrid of MulTv and multidimensional HLL scheme based on Self-similar structures),is *** simulates the strongly interacting zone by adopting the MHLLES(Multidimensional Harten-Lax-van Leer-Eifeldt scheme based on Self-similar structures)scheme at subsonic speeds,which is with a high resolution by considering the second moment in the similarity ***,it adopts the MULTV(Multidimensional Toro and Vasquez)scheme,which is with a high resolution in capturing discontinuities,to simulate the flux at supersonic *** numerical experiments,including both one-dimensional cases and twodimensional cases,are ***-dimensional moving contact discontinuity case and sod shock tube case suggest that HMTHS can accurately capture one-dimensional expansion waves,shock waves,and linear contact ***-dimensional cases,such as the double Mach reflection case,the supersonic shock/boundary layer interaction case,the hypersonic flow over the cylinder case,and the hypersonic viscous flow over the double-ellipsoid case,indicate that the HMTHS scheme is with a high resolution in simulating multidimensional complex ***,it is promising to be widely applied in both scholar and engineering areas.

关键词： complex flows Computational fluid dynamics Multidimensional Riemann solver Self-similar

An optimization approach to the similarity criteria of flows and its application

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Progress in Natural Science:Materials International 2006年第3期16卷 241-247页

作者： ZHOU Jifu and LI Jiachun (Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

In the present paper, we propose an optimization approach to investigate the similarity criteria of complex flows. With this approach, we may identify the dominant dimensionless variables governing complex flows by numerical sensitivity analysis. Firstly, we define the sensitivity factor and examine its dependence on the dimensionless variables. Then, we apply this approach to study the similarity criteria of porous media flow in a presumed oil reservoir. The similarity principle obtained from the numerical sensitivity analysis is in agreement with the theoretical law, thus demonstrating the feasibility of the proposed optimization approach. Further explanation is given by analyzing the deviation of pressure distribution in a model from its prototype. In addition, we examine the effects of flow parameter variation on the sensitivity factors and find that the dominant dimensionless variables may change from different sets of parameters.

关键词： similarity optimization sensitivity analysis complex flows model.

BLOCKAGE　COEFFICIENT　TECHNIQUE　FOR　SQUARE　ENCLOSURE　FLOW　WITH　NO　THICKNESS　SPACERS

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Journal of Hydrodynamics 1996年第1期8卷 93-102页

作者： Yu Li-ren(Dept. of Hydraulics and Sanitary Engineering,School of Engineering at Sao Carlos,University of Sac Paulo,Brazil visiting professor & researcher,supported by CNPq.)Antonio M Righetto(Dept. of Hydraulics and Sanitary Engineering, School of Enginee Univ. of Sao Paulo Sao Paulo Brazil

In this paper,the face blockage coefficient technique and finite volume approach are used to solve numerically the complete N. -S. (Navier-Stokes) equations in a three-dimensional square enclosure with no thickness spacers. The pressure-velocity correction algorithm (SIM PLE -C, Semi-Implicit Method for Pressure Linked Equation Consistent) is adopted in a direct calculation of all physical variables. The computations are performed in three grids with different density. The applicability, feasibility and efficiency of the face blockage coefficient technique applied to simulate three-dimensional viscous flows are investigated and discussed. The computational results of the square enclosure with no thickness spacers have been compared with the numerical results of the enclosure with thickness spacers,which were obtained by using both the face and volume blockage coefficients. The present research shows that the blockage coefficient technique is a simple and convenient numerical technique,with encouraging prospects, for computing the velocity,pressure and other physical quantities of the complex flows in a channel with thin internal spacers and barricades.

关键词： channel complex flows blockage coefficient technique

DIGITAL ANALYSIS TECHNOLOGY FOR MORPHOLOGY OF POLYMER CHAIN COILS IN FLOW FIELDS

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Chinese Journal of Polymer Science 2005年第2期23卷 155-158页

作者： Chi-xingZhou HongZheng WeiYu DepartmentofPolymerScience＆Engineering ShanghaiJiaotongUniversityShanghai200240China

Polymer chain coils with entanglement is a crucial scale of structures in polymer materials since their relaxationtimes are matching practical processing *** on the phenomenological model of polymer chain coils and a new finiteelement approach,we have designed a computer software including solver,pre-and post-processing modules,and developeda digital analysis technology for the morphology of polymer chain coils in flow fields(DAMPC).Using this technology wemay simulate the morphology development of chain coils in various flow fields,such as simple shear flow,elongational flow,and any complex flow at transient or steady *** applications made up to now show that the software predictions arecomparable with experimental results.

关键词： Morphology of polymer chain complex flows Conformation tensor Finite element method(FEM) Software DAMPC.