Numerical Study Of Flow And Hear Transfer Control On Electrolyte Solution In Micro/nano Channel

Microfluidic chips have a widely applications on microelectronics,microelectromechanical systems.In which,the stability and reliability of system is directly influenced by temperature rising caused by heat production from electronic components.Therefore,efficient cooling techniques in this system are of great importance.In this work,the fluid flow and heat transfer features of electrolytic solution in micro/nano-channels are studied.Simulations are based on the electric double layer model and electrokinetic transport theory.The main topics studied in this thesis are as follows:(1)Optimize the theoretical model of the electric double layer in micro/nanochannels.Consider the Stern layer and multiple ion effect in the theoretical model.Then,numerically solve the coupled Poisson equation,Nernst-Planck equation and NavierStokes equations.Investigate the influences of Stern layer on the surface charge density,Zeta potential and ICP effect under different ion concentration and PH range.Analyze the accuracy difference with and without the Stern layer.(2)Consider the energy transport process in the electric double layer,and conduct a systematically study on heat transfer phenomena in micro/nano-channel electrolyte solution under different driving forces such as pressure-driven and electrically driven conditions.Derive the dimensionless governing equations,and find the control parameters,and then numerically studied the flow and heat transfer in electrolyte solution within rectangular micro-channels.An advanced heat transfer control technique is proposed,using the field effect transistor to modify surface potential of the micro-channel and then change the its heat exchange performance.Besides,the influence of the electrical potential on the Nu number of the microchannel is numerically analyzed.(3)Investigate the flow and heat transfer characteristics of the electrolyte solution in the three-dimensional microchannel under the coupled effects of the electric field and the magnetic field.Derive the dimensionless governing equations,find the control parameters for the coupled system,and studied the effects of control parameters on heat transfer performance.Then,design the orthogonal experiments,validate the results using the range analysis method,and then obtain the optimal adjustment schemes of the influencing factors.Finally,conduct a sensitivity analysis on main influence factor,and improve the heat transfer performance on micro/nano-channels.