Abstract: High efficiency heat exchanger is needed for electronic cooling, otherwise, the operating temperature of the electronic devices and micro systems could reach values where the components loose their physical integrity, and the related function would cease. Due to the large heat transfer surface area to volume ratio, microchannels cooling with gas or liquid coolant have been shown to be strong prospects. Therefore, research on the flow and heat transfer in these microchannels is as important topic.
Based on Kn number, the gas flow in microchannel is classified into four flow regimes: continuum flow regime, slip flow regime, transition flow regime and free molecular flow regime. The flow in many applications of the micro/nano systems, such as hard disk drive, micro pumps, micro valves and micro nozzles, is in slip and transition flow regime, which is characterized by slip flow at wall. Here, we modeled the flow in slip and transition flow regime, and give the purely analytical solution by homotopy analysis method(HAM). The results are validated by comparing the numerical results. Effect of key parameters on flow characteristics are discussed in details. Also, an "inverted velocity" profile, which has been found by other investigators by using molecular-based method, is found by solving the conventional governing equations, which are Navier-Stokes equations, combined with high-order accurate slip boundary conditions.

Brief Biography of the Speaker:
Tiantian Zhang is currently a visiting scholar at Rutgers University (RU) in NJ, USA. He is a PhD in Beijing Jiaotong University (BJTU). He got his bachelor degree from Huazhong University of Science and Technology (HUST). His current research interests include micro/nano-scale flow and heat transfer, design and optimize micro heat sink, CFD et al. He has published about 20 peer reviewed papers. He is member of APS and ASME. Also, He is referee for some archival journals.