http://hdl.handle.net/2173/31804 Sat, 25 May 2013 21:32:56 GMT 2013-05-25T21:32:56Z http://hdl.handle.net/2173/111562 Title: Numerical study of wave propagation in compressible two-phase flow Authors: Zeidan, D.; Romenski, E.; Slaouti, Arezki; Toro, E. F. Abstract: We propose a new model and a solution method for two-phase two-fluid compressible flows. The model involves six equations obtained from conservation principles applied to a one-dimensional flow of gas and liquid mixture completed by additional closure governing equations. The model is valid for pure fluids as well as for fluid mixtures. The system of partial differential equations with source terms is hyperbolic and has conservative form. Hyperbolicity is obtained using the principles of extended thermodynamics. Features of the model include the existence of real eigenvalues and a complete set of independent eigenvectors. Its numerical solution poses several difficulties. The model possesses a large number of acoustic and convective waves and it is not easy to upwind all of these accurately and simply. In this paper we use relatively modern shock-capturing methods of a centred-type such as the total variation diminishing (TVD) slope limiter centre (SLIC) scheme which solve these problems in a simple way and with good accuracy. Several numerical test problems are displayed in order to highlight the efficiency of the study we propose. The scheme provides reliable results, is able to compute strong shock waves and deals with complex equations of state. Description: Full-text of this article is not available in this e-prints service. This article was originally published [following peer-review] in International Journal for Numerical Methods in Fluids, published by and copyright John Wiley & Sons. Sat, 01 Dec 2007 00:00:00 GMT http://hdl.handle.net/2173/111562 2007-12-01T00:00:00Z http://hdl.handle.net/2173/91057 Title: A vorticity-based method for incompressible unsteady viscous flows Authors: Qian, Ling Abstract: A novel approach is presented, based on the integral form of the vorticity formulation, in which the vorticity transport equation is solved by using the cell-centred finite-volume method, while the velocities needed at the centre of each control volume are calculated by a modified Biot–Savart formula in conjunction with a fast summation algorithm. The vorticity and mass conservation in the flow are guaranteed during the calculation by virtue of the finite volume approach and the method of implementing the boundary conditions at the body surface. As an example, both the early stage development and long term evolution of the flow around an impulsively started circular cylinder are computed using the method. The present results are compared with other numerical and experimental results for the same flow problem and show good agreement. Description: Full-text of this article is not available in this e-prints service. This article was originally published [following peer-review] in Journal of computational physics, published by and copyright Academic Press. Sat, 01 Sep 2001 00:00:00 GMT http://hdl.handle.net/2173/91057 2001-09-01T00:00:00Z http://hdl.handle.net/2173/81455 Title: Numerical solution for hyperbolic conservative two-phase flow equations Authors: Zeidan, D.; Slaouti, Arezki; Romenski, E.; Toro, E. F. Abstract: We outline an approximate solution for the numerical simulation of two-phase fluid flows with a relative velocity between the two phases. A unified two-phase flow model is proposed for the description of the gas–liquid processes which leads to a system of hyperbolic differential equations in a conservative form. A numerical algorithm based on a splitting approach for the numerical solution of the model is proposed. The associated Riemann problem is solved numerically using Godunov methods of centered-type. Results show the importance of the Riemann problem and of centered schemes in the solution of the two-phase flow problems. In particular, it is demonstrated that the Slope Limiter Centered (SLIC) scheme gives a low numerical dissipation at the contact discontinuities, which makes it suitable for simulations of practical two-phase flow processes. Description: Full-text of this article is not available in this e-prints service. This article was originally published International Journal of Computational Methods, published by and copyright World Scientific Publishing Co. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/2173/81455 2007-01-01T00:00:00Z http://hdl.handle.net/2173/35958 Title: Numerical solution for the mixed convection flow of a micropolar fluid past a continuously moving plate Authors: Bhargava, Rama; Agarwal, R. S.; Kumar, Lokendra; Takhar, Harmindar S. Abstract: Boundary layer solutions are presented to investigate the mixed convection flow characteristics from a continuous flat surface moving in a parallel free stream of micropolar fluid. The partial differential equations governing the flow and temperature functions are reduced to ordinary differential equations, which are solved numerically, using the finite difference method. The numerical values of the skin friction and the rate of heat transfer are given in the tables. The effect of Grashof number G and Prandtl number Pr on the velocity, microrotation and temperature functions has been studied. Description: Full-text of this article is not available in this e-prints service. This article was originally published in the International journal of heat and technology, published by and copyright Edizioni E. T. S. Tue, 01 Jan 2002 00:00:00 GMT http://hdl.handle.net/2173/35958 2002-01-01T00:00:00Z