Active Mixing in a Microchannel

We investigate a minute magneto hydro-dynamic mixer with relatively rapid mixing enhancement experimentally and analytically. The mixer is fabricated with brass and polymethyl methacrylate （PMMA） layers. A secondary flow is generated by using the Lorentz force in the fluids. The efficiency of mixing is greatly improved due to the large increase of the contact area between two mixing fluids. The micro particle image velocimetry technique is employed to measure the fluid flow characteristics in the micro-channel. Numerical simulation is performed based on the theoretical model of the computational fluid dynamics and the electromagnetic field theory. The experimental results are in good agreement with the numerical results, which indicates that the mixing area is enlarged by the driving of Lorentz force and the mixing can be enhanced.     

在动网格上的多介质界面数值处理方法研究

运用动网格上的ALE方法对一维可压缩多介质Riemann问题进行求解,在处理介质界面 上的数值通量时提出了3种不同的数值方法：Lagrange方法、GFM和HLLC方法,并且对 这3种方法的数值结果进行了比较,认为GFM方法和HLLC方法在介质界面上出现大压力 梯度时能够明显消除界面上密度的非物理震荡,提高介质界面上数值解的精度.