检索结果-南通市图书馆

Interaction of weak free-stream disturbance with an oblique shock： validation of the shock-capturing method

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1601-1612页

作者： Caihong SU Jinlei GENG Department of Mechanics Tianjin University Tianjin 300072 China

Transition prediction is of great importance for the design of long distance flying vehicles. It starts from the problem of receptivity, i.e., how external disturbances trigger instability waves in the boundary layer. For super/hypersonic boundary layers, the external disturbances first interact with the shock ahead of the flying vehicles before entering the boundary layer. Since direct numerical simulation （DNS） is the only available tool for its comprehensive and detailed investigation, an important problem arises whether the numerical scheme, especially the shock-capturing method, can faithfully reproduce the interaction of the external disturbances with the shock, which is so far unknown. This paper is aimed to provide the answer. The interaction of weak disturbances with an oblique shock is investigated, which has a known theoretical solution. Numerical simulation using the shock-capturing method is conducted, and results are compared with those given by theoretical analysis, which shows that the adopted numerical method can faithfully reproduce the interaction of weak external disturbances with the shock.

关键词： shock high speed flow free-stream disturbance shock-capturing

Developing shock-capturing difference methods

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2007年第4期28卷 477-486页

作者：涂国华袁湘江陆利蓬 China Aerodynamics Research and Development Center Mianyang 621000Sichuan ProvinceP. R. China Tianjin Key Laboratory of Modern Engineering MechanicsTianjin 300072P. R. China National CFD LaboratoryBeihang UniversityBeijing 100083P. R. China China Aerodynamics Research and Development Center Mianyang 621000Sichuan ProvinceP. R. China National CFD LaboratoryBeihang UniversityBeijing 100083P. R. China School of Jet Propulsion Beihang UniversityBeijing 100083P. R. China

A new shock-capturing method is proposed which is based on upwind schemes and flux-vector splittings. Firstly, original upwind schemes are projected along characteristic directions. Secondly, the amplitudes of the characteristic decompositions are carefully controlled by limiters to prevent non-physical oscillations. Lastly, the schemes are converted into conservative forms, and the oscillation-free shock-capturing schemes are acquired. Two explicit upwind schemes （2nd-order and 3rd-order） and three compact upwind schemes （3rd-order, 5th-order and 7th-order） are modified by the method for hyperbolic systems and the modified schemes are checked on several one-dimensional and two-dimensional test cases. Some numerical solutions of the schemes are compared with those of a WENO scheme and a MP scheme as well as a compact-WENO scheme. The results show that the method with high order accuracy and high resolutions can capture shock waves smoothly.

关键词： high order scheme shock-capturing upwind scheme compact scheme high resolution conservative scheme

A Hybrid Finite-Volume and Finite Difference Scheme for Depth- Integrated Non-Hydrostatic Model

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2017年第3期31卷 261-271页

作者： YIN- Jing SUN Jia-wen WANG Xing-gang YU Yong-hai SUN Zhao-chen National Marine Environmental Monitoring Center Dalian 116023 China Key State Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116023 China Nanjing Hydraulic Research Institute Nanjing 210029 China

A depth-integrated, non-hydrostatic model with hybrid finite difference and finite volume numerical algorithm is proposed in this paper. By utilizing a fraction step method, the governing equations are decomposed into hydrostatic and non-hydrostatic parts. The first part is solved by using the finite volume conservative discretization method, whilst the latter is considered by solving discretized Poisson-type equations with the finite difference method. The second-order accuracy, both in time and space, of the finite volume scheme is achieved by using an explicit predictor-correction step and linear construction of variable state in cells. The fluxes across the cell faces are computed in a Godunov-based manner by using MUSTA scheme. Slope and flux limiting technique is used to equip the algorithm with total variation dimensioning property for shock capturing purpose. Wave breaking is treated as a shock by switching off the non-hydrostatic pressure in the steep wave front locally. The model deals with moving wet/dry front in a simple way. Numerical experiments are conducted to verify the proposed model.

关键词： non-hydrostatic model shock-capturing wave breaking finite volume method MUSTA scheme

A HIGHLY ACCURATE NUMERICAL METHOD FOR FLOW PROBLEMS WITH INTERACTIONS OF DISCONTINUITIES

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2002年第1期20卷 1-14页

作者： Xiao-nan Wu You-lan Zhu Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong Kong Department of Mathematics University of North Carolina at CharlotteCharlotteNC 28223

Focuses on a study wherein a type of shock fitting method has been used to solve dimensional flow problems with interactions of various discontinuities. Discretization of the transformed equations; Numerical results; ... 详细信息

关键词： interaction of discontinuity shock-fitting shock-capturing

Analysis of Discontinuity Detectors and Hybrid WCNS Schemes Based on Waveform Recognition

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2023年第7期34卷 418-455页

作者： Hao Zhang Yidao Dong Shichao Zheng Xiaogang Deng College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China Institute of System Engineering Academy of Military SciencesBeijing 100082China

In this paper,we present a hybrid form of weighted compact nonlinear scheme(WCNS)for hyperbolic conservation laws by applying linear and nonlinear methods for smooth and discontinuous zones *** fulfill this algorithm,it is inseparable from the recognition ability of the discontinuity detector *** specific,a troubled-cell indicator is utilized to recognize unsmooth areas such as shock waves and contact discontinuities,while avoiding misjudgments of smooth *** classical detectors are classified into three basic types:derivative combination,smoothness indicators and characteristic ***,a new improved detector is proposed for *** they are analyzed through identifying a series of waveforms *** that,hybrid schemes using such indicators,as well as different detection variables,are examined with Euler equations,so as to investigate their ability to distinguish practical discontinuities on various *** results demonstrate that the proposed algorithm has similar performances to pure WCNS,while it generally saves 50 percent of CPU time for 1D cases and about 40 percent for 2D Euler *** research is in the hope of providing some reference and establishing some standards for judging existing discontinuity detectors and developing novel ones.

关键词： WCNS waveform detection troubled-cell indicator shock-capturing hybrid scheme

A Parameter–Free Generalized Moment Limiter for High-Order Methods on Unstructured Grids

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2009年第4期1卷 451-480页

作者： Michael Yang Z.J.Wang Department of Aerospace Engineering and CFD Center Iowa State UniversityAmesIA 50011USA

A parameter-free limiting technique is developed for high-order unstructured-grid methods to capture discontinuities when solving hyperbolic conservation *** technique is based on a“troubled-cell”approach,in which cells requiring limiting are first marked,and then a limiter is applied to these marked cells.A parameter-free accuracy-preserving TVD marker based on the cell-averaged solutions and solution derivatives in a local stencil is compared to several other markers in the literature in identifying“troubled cells”.This marker is shown to be reliable and efficient to consistently mark the *** a compact highorder hierarchical moment limiter is developed for arbitrary unstructured *** limiter preserves a degree p polynomial on an arbitrary *** a result,the solution accuracy near smooth local extrema is *** results for the high-order spectral difference methods are provided to illustrate the accuracy,effectiveness,and robustness of the present limiting technique.

关键词： Limiter shock-capturing high-order unstructured grids

Two-dimensional flood routing in an urban environment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Two-dimensional flood routing in an urban environment