Research On Mixing Performance Of The New Split Micro Channel

An important developing way of modern natural science and engineering technology is Miniaturization, micro system is an important development direction of modern manufacturing technology. Micro-fluidic chip is used for biological or chemical experiment research. It uses the method of corresponding high-end MEMS processing, in the micro channel is the main part, processing to the scope will be used in the experiment function unit according to the proportion of reduced to hundreds of microns or hundreds of mm internal chip, implement various reactions, the entire laboratory separation, detection and other functions. Micro mixer is an important component in a micro-fluidic chip. The mixing effect has great impact on the performance of micro-fluidic chip. So improving the mixing efficiency of micro channel in micro-fluidic chip has been a important research field. The development of more types of micro channel to improve the mixing efficiency, meet the needs of research and production is essential. And this paper developed a analysis model of the micro channel structure. The structure increases the degree of mixing through increasing the shunt and convection of fluid, so the fluid can be mixed more fully and uniformly. This paper studied the mixing performance of micro-channel by numerical simulation of Fluent.First of all, take numerical optimization of structure parameters on the model of micro channel from the analysis of the angle and the depth width ratio. The result showed that:the model analysis of micro structure model of the best channel mixing effect is θ=70°, H/W=1. It means that when the entrance velocity V>lm/s, the mixer can achieve effective mixing, and the mixing index is.less than 0.03.Especially when the entrance velocity reaches to 15m/s, the mixing index of the micro channel reduced to 0.0032, and basically reached the complete mixing.Secondly, in order to find the influence rules of operation parameters on the micro-channel, it took numerical simulation from the entrance velocity, diffusion coefficient and viscosity. It obtained the different properties of parameter change on the influence law of mixed operation, and the fitted correlation of operation parameters and the length of channel. It would play a great role in guiding the design and manufacture of micro channel length.Finally, in order to prove the mixing performance of the micro channel, we compared it with Z channel type in the same operating parameters, including the mixing length, mixing time and pressure drop. The results found that, no matter what the viscosity changed, the mixing time and the mixing length of the new micro-channel are less than the other two channels with a certain degree of mixing, and it also owned the highest mixing efficiency; The pressure loss of the new micro-channel was a little higher than Z type channel at a certain speed, but it didn’t take any effect. Generally speaking, the mixing performance of the new micro-channel was better than the two other micro channels, and the pressure loss was not much difference. The new micro-channel could be used in micro-fluidic chip.