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根据对流迎风分裂(AUSM)思想提出一种通量分裂方法,称为K-CUSP格式.它与传统H-CUSP和E-CUSP格式的最大差异在于总能量的分裂:K-CUSP格式将无粘守恒通量中所有的运动学量分裂到对流项,所有的热力学量分裂到压力项,即总能量被分裂成动能和静焓.对于压力项的数值通量,采用一种新的界面构造方法.数值测试表明:①K-CUSP格式继承了FVS格式的简单性和稳健性.在激波后不易出现压力过冲,在膨胀区域没有振荡,优于AUSM和WPS格式;②K-CUSP格式继承了FDS格式的分辨率.激波间断的分辨率和H-CUSP、E-CUSP格式基本相同,接触间断的分辨率高于FVS格式,低于Roe、AUSM和WPS格式.AUSM和WPS格式在计算运动接触间断时,速度存在很大振荡,而新格式不存在振荡. 相似文献
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Sudipta De Murugan Thangadurai 《International Journal of Computational Fluid Dynamics》2013,27(6):345-354
Vortices generated at the open end of a planar shock tube are numerically simulated using the AUSM+ scheme. This scheme is known to have low numerical dissipation and therefore is suitable for capturing unsteady vortex motion. However, this low numerical dissipation can also cause oscillations in the vorticity field. Numerical experiments presented here highlight the effect of numerical dissipation on the simulated vortex, as well as the role played by turbulence models. Two turbulence models – the shear-stress-transport (SST) and its modified version for unsteady flows (SST-SAS) – are employed to observe the effect of including turbulence models in such complex flows where the vortex has an embedded shock. 相似文献
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Xue-song Li 《International Journal of Computational Fluid Dynamics》2014,28(6-10):329-338
Many ideas exist for the development of shock-capturing schemes, such as Roe, Harten–Lax–van Leer (HLL) and advection upstream splitting method (AUSM) families, and their extension for all-speed flow. A uniform algorithm that expresses the three families in the same framework is proposed in this study. The algorithm has an explicit physical meaning, provides new understanding and comparison of the mechanism of schemes, and may play a significant role in further research. As an example of applying the uniform algorithm, the low Mach number behaviour of the schemes is analysed. A clear and simple explanation is provided based on the wall boundary, and a concise rule is proposed to determine whether a scheme has satisfied low Mach number behaviour. 相似文献
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This paper makes the first attempt of extending implicit AUSM‐family schemes to multiphase flow simulations. Water faucet, air–water shock tube and oscillating manometer problems are used as benchmark tests with the generic four‐equation two‐fluid model. For solving the equations implicitly, Newton's method along with a sparse matrix solver (UMFPACK solver) is employed, and the numerical Jacobian matrix is calculated. Comparison between implicit and explicit AUSM‐family schemes is presented, indicating that similarly accurate results are obtained with both schemes. Furthermore, the water faucet problem is solved using both staggered and collocated grids. This investigation helps integrate high‐resolution schemes into staggered‐grid‐based computational algorithms. The influence of the interface pressure correction on the simulation results is also examined. Results show that the interfacial pressure correction introduces numerical dissipation. However, this dissipation cannot eliminate the overshoots because of the incompatibility of numerical discretization of the conservative and non‐conservative terms in the governing equations. The comparison of CPU time between implicit and explicit schemes is also studied, indicating that the implicit scheme is capable of improving the computational efficiency over its explicit counterpart. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This paper first applies a flux vector‐type splitting method based on the numerical speed of sound for computing incompressible single and multifluid flows. Here, a preconditioning matrix based on Chorin's artificial compressibility concept is used to modify the incompressible multifluid Navier–Stokes equations to be hyperbolic and density or volume fraction‐independent. The current approach can reduce eigenvalues disparity induced from density or volume fraction ratios and enhance numerical stability. Also, a simple convection‐pressure flux‐splitting method with high‐order essentially nonoscillatory‐type primitive variable extrapolations coupled with monotone upstream‐centered schemes for conservation laws‐type volume fraction recompressed reconstruction is used to maintain the preservation of sharp interface evolutions in multifluid flow simulations. Benchmark tests including a solid rotation test of a notched two‐dimensional cylinder, the evolution of spiral and rotational shapes of deformable circles, a dam breaking problem, and the Rayleigh–Taylor instability were chosen to validate the current incompressible multifluid methodology. An incompressible driven cavity was also chosen to check the robustness of the proposed method on the computation of single fluid incompressible flow problems. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Advection upstream splitting method (AUSM) and Harten-Lax-van Leer with contact (HLLC) are two popular families of flux functions. The AUSM is simple and requires no eigenstructure, which facilitates its extensions to general equations of state. Furthermore, one of its variants, simple low-dissipation AUSM (SLAU), is applicable to all speeds and features removal of parameter setting by the user. HLLC, on the other hand, clearly defines three distinct waves in Riemann problem, namely, left-running and right-running acoustic waves, and entropy wave. This paper demonstrates that HLLC can be written in a very similar form with the AUSM family and that the similar manner in extending AUSM family to all speeds is easily incorporated into HLLC in this AUSM-like form. Then, we combine the strengths of the both flux functions and offer a new inviscid numerical flux function within the framework of monotone upwind scheme for conservation laws (MUSCL) in computational fluid dynamics (CFD) for Euler and Navier-Stokes equations. The resultant HLLC with low dissipation (HLLCL) numerical flux can compute low Mach number flows and sound propagations at the same time with high accuracy, as demonstrated by one-dimensional and two-dimensional numerical examples. Furthermore, the results indicate that its extensions to general fluids such as supercritical fluids are encouraging. 相似文献
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