Woodruff School of Mechanical Engineering



Flow Boiling in Micro-channels


Prof. Mrinal Jagirdar


National University of Singapore


Tuesday, February 7, 2017 at 11:00:00 AM


MRDC Building, Room 3515


Dr. Yogendra Joshi


The target heat flux removal from microelectronics would soon be greater than 100 W/cm2. Moreover for some military applications like lasers and radars, the challenge is to remove heat fluxes exceeding 10,000 W/cm2. Flow boiling in micro-channels is a very strong candidate for cooling of such applications. Its advantages include a very high heat transfer coefficient, high heat flux removal potential, excellent temperature uniformity, small flow rate requirement, hot spot mitigation capability and compact design. Over and above the constant need to push boundaries further vis-à-vis removing greater heat fluxes at lower wall temperature, the challenges that limit its commercial applications include a lack of fundamental understanding of boiling mechanisms that can potentially lead to development of mechanistic predictive models.The research work conducted at the Micro-Thermal Systems (MTS) Group headed by Assoc. Prof. Lee Poh Seng at the National University of Singapore includes studies on novel geometries that show significantly enhanced performance as well as fundamental studies that help understand flow boiling heat transfer mechanisms. This presentation would highlight performance of various geometries such as oblique fins, stepped fins and micro-gap as well as highlight the fundamental studies on flow-boiling carried out by analyzing transient heat transfer data captured synchronously with flow visualizations. Finally, non-optical flow-regime detection techniques using temperature transients shall be discussed


Dr. Mrinal Jagirdar is a Research Fellow at National University of Singapore