MAE Seminar: Nanoscale Transport in Aerospace, Nanoelectronics and Sensor Systems
Director, Center for Integrated Thermal Management of Aerospace Vehicles (CITMAV)
University of California, Los Angeles and Purdue University
Mechanical & Aerospace Engineering
Abstract: This talk will present tunable cooling technology concepts befitting fast transient thermal events. The talk will provide an overview of CITMAV projects that seek to harness and control dynamic thermal management technologies. In one approach, the rapid depressurization of a working fluid triggers coincident flash boiling and desorption events, thereby achieving very high cooling rates for short periods of time. Carbon-based foam, derived through the chemical modification of a highly graphitized carbon precursor, is utilized because of its relatively high thermal conductivity, adsorptive properties and open macroporous structure. We anticipate that this combination of technologies will achieve instantaneous peak cooling rates surpassing those other advanced cooling systems in a manner appropriate for transient thermal events. Early results, for example, indicate a flat temperature response over a 3-5 sec. period during controlled flash boiling under moderately high heat fluxes. Moreover, the approach elicits new system-level concepts that require co-development in order to exploit such phenomena in practical applications. The presentation will close with several fast energy-related examples, such as supercapacitors in which similar connections between materials and transport are paramount.
Bio: Timothy S. Fisher earned his doctorate in mechanical engineering in 1998 at Cornell University. He joined UCLA’s Department of Mechanical & Aerospace Engineering after spending 15 years at Purdue’s School of Mechanical Engineering, and several previous years at Vanderbilt University. He is an adjunct professor in the International Centre for Materials Science at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) and co-directs the JNCASR-Purdue Joint Networked Centre on Nanomaterials for Energy. From 2009 to 2012, he served as a research scientist at the Air Force Research Laboratory’s newly formed Thermal Sciences and Materials Branch of the Materials and Manufacturing Directorate. He is active in service to the American Society of Mechanical Engineers through a variety of responsibilities. Fisher is a former co-editor of the journal Energy Conversion & Management and currently is specialty chief editor for Thermal and Mass Transport of the journal Frontiers in Mechanical Engineering.