The turbulent flow of vertical plane wall plume with concentration variation was studied with the finite analytical method. The k-epsilon model with the effect of buoyancy on turbulent kinetic energy and its dissipation rate was adopted. There were similarity solutions in the uniform environment for the system of equations including the equation of continuity, the equation of momentum along the flow direction and concentration, and equations of k, epsilon. The finite analytic method was applied to obtain the similarity solution. The calculated data of velocity, relative density difference, the kinetic energy of turbulence and its dissipation rate distribution for vertical plane plumes are in good agreement with the experimental data at the turbulent Schmidt number equal to 1.0. The variations of their maximum value along the direction of main flow were also given. It shows that the present model is good, i.e., the effect of buoyancy on turbulent kinetic energy and its dissipation rate should be taken into account, and the finite analytic method is effective.
The RNG k-εmodel considering the buoyancy effect,which is solved by the hybrid finite analytic method,is used to simulate the mixture of the horizontal round thermal buoyant jet in compound open channel flow.The mixing features near the spout and flowing characteristic of the secondary currents are studied by numerical simulation. Meanwhile,(1) the distribution of the measured isovels for stream-wise velocity,(2) sec- ondary currents,(3) the distribution of the measured isovels for temperature of typical cross-section near the spout,were obtained by the three-dimensional Micro ADV and the temperature measuring device.Compared with experimental data,the RNG k-εmodel based on buoyancy effect can preferably simulate the jet which performs the bifurcation phenomenon,jet reattachment (Conada effect) and beach secondary currents phenomenon with the effect of ambient flow,buoyancy,and secondary currents of compound section and so on.
A finite proximate method was presented to solve the convection-diffusion equation in curvilinear grids. The method has characteristics of automatic upwind effect and the good stability. It was verified through exact solution and other calculation results of two-dimensional dam-break flow in a frictionless, horizontal channel. The calculation results are in good agreement with the exact solution and other calculation results, which show that the finite proximate method can be applied to solve the convection-diffusion equation directly not only in the rectangular grids, but also in the curvilinear grids.
ZHAO Ming-deng LI Tai-ru HUAI Wen-xin LI Liang-liang
