Date of this Version
Wallis, S. J. (2017), "Design and Validation of an Experimental Setup to Study Single Phase Heat Transfer Enhancement of Femtosecond Laser Processed Metallic Surfaces", M.S. thesis, Mechanical and Materials Engineering, University of Nebraska-Lincoln.
In the present work, a single phase flow heat transfer experimental loop was designed with the intention of studying the effects of femtosecond laser surface processing (FLSP) on metallic surfaces with the specific goal of enhancing heat transfer in compact heat exchangers currently in use by NASA. This experimental setup went through two major design iterations which are detailed in this thesis. The first iteration consisted of a counterflow fluid-to-fluid heat exchanger, which measured overall heat transfer coefficients and pressure drops, where the overall heat transfer coefficient is defined in terms of the total thermal resistance to heat transfer between two fluids. Test results of overall heat transfer coefficients and pressure drops for smooth and FLSP processed minichannels were obtained with this design. Because of the difficulty in comparing overall heat transfer coefficients for minichannels with highly differing surface roughness, the experimental setup was redesigned to be capable of measuring heat transfer coefficients for single channel flow. The final design iteration uses a constant applied heat flux on a single minichannel to allow for measurement of heat transfer coefficients. Heat transfer coefficients for an FLSP 316 stainless steel surface have been obtained with this single minichannel design. Results show no enhancement in the heat transfer coefficient of the FLSP 316 stainless steel surface.
Advisors: Sidy Ndao and George Gogos