Papers by Author: Wen Li Wei

Abstract: The technique of curvilinear boundary-fitted coordinate system is used for the mathematical model of pressure underground seepage flow and the boundary conditions and the method of solving the transformed equations have been presented. The computing example shows that the computed hydraulic parameters conform to the physical laws. Compared with the finite element method, the presented method need not solve the large matrix equations, and the computer memories and the time for computing are less. The mathematical model is effective for numerical solution of seepage flows with complicated boundaries, and can be used in practice hydraulic engineering.

Abstract: In this paper, we use two-phase mixture model and the 3D Realizable k-ε turbulence model to numerically simulate the advection secondary turbulence flow in a circular secondary clarifier. The PISO algorithm is used to decouple velocity and pressure. The results show that the model can provide a reference in designing sedimentation tanks.

Abstract: This paper is concerned with a new numerical method of two-dimensional flow. The governing system of differential equations is transformed into an equivalent system applied over a square-grid network in order to overcome the difficulties and inaccuracies associated with the determination of characteristics near the flow boundaries. The MacCormack two-step explicit scheme with second-order accuracy is used for the solution of the transformed system of equations. The present numerical model has been used to numerically compute flow in sharply curved channel.

Abstract: A numerical study of the flow over a two-dimensional car model in proximity to the ground is presented. The numerical method is based on a pressure-correction algorithm of the SIMPLE-type．A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence, while as a turbulence model the standard κ-ε model with wall functions is used. The numerical results for the u and v velocity ,as well as for the pressure distribution over the car surface are obtained．

Abstract: Numerical modeling of open channel flows with dam-break using explicit finite difference schemes is constrained by the choice of time step, which is limited by the CFL stability criteria. To overcome this limitation, in this work we introduce the application of an algorithm to the field of computational hydraulics. By coupling this algorithm to a second-order accurate MacCormack scheme, we demonstrate that the solution can be accelerated to the desired transient state. The present formulation has been tested to simulate a dam-break flow. The close agreement between the obtained results and the theoretical findings indicates the reliability of the proposed algorithm.

Abstract: A kind of dynamic tracking system for conducting high accuracy measurement of transparent liquid concentration is designed by means of line matrix CCD receiving fringes in accordance with the relations between liquid concentration and refractive index as well as the relations among refractive index, interference light wavelength of optical fiber F-P interferometer and grade orders. The detecting system can recognize or detect 0.01% of concentration variations via measuring a group of alcohol.