Papers by Author: Yu Ling Liu

Abstract: In this paper, we use solid–liquid two-phase mixture model and the k-ε turbulence model to numerically simulate the effects of the position of baffles on the removal rate of solids in a sedimentation tank. The PISO algorithm is used to decouple velocity and pressure. The distribution of sludge concentration on different cross-sections is obtained by the proposed model.

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: A numerical model for simulating of 2D flow around a spur dike was presented by using the physical fractional-step method. The water governing equations were separated into three parts. The first is a convective problem; the second is a diffusive problem; and the third is a source term. The advantage of this method is that in the convective-diffusion equation a more reasonable scheme for the convective and diffusive operator is adopted respectively. Numerical simulation for 2D flow around a spur dike was implemented. The comparisons with other numerical solutions show that the proposed method can be capable of dealing with 2D spur-dike flows.

Abstract: This paper is concerned with a mathematical model for numerical simulation of 2D flow accompanied with a hydraulic jump. The governing water equations are solved by the MacCormack’s predictor-corrector technique. The mathematical model is used to numerically predict 2D hydraulic jump in a rectangular open channel. The comparison and the analysis show that the proposed method is accurate, reliable and effective in simulation of hydraulic jump flows.

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: 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.