Expanded microchannel heat exchanger: Nondestructive evaluation

David C. Denkenberger, Tennessee State University
Michael Brandemuehl, University of Colorado at Boulder
Joshua M. Pearce, Michigan Technological University
John Zhai, University of Colorado at Boulder


Recent theoretical developments in expanded microchannel polymer-based heat exchangers were promising, but the initial experiments underperformed simple theory. In order to understand this discrepancy, this article introduces a nondestructive methodology for characterizing polymer heat exchangers. A computerized tomography (X-ray) scan was performed to diagnose the problem. The method was tested on the expanded microchannel polymer heat exchanger to determine the variations in geometry between the theoretical and experimental heat exchanger. Channels were found to have variable heights causing flow maldistribution. The results are discussed to guide further technological development of this approach to heat exchanger design and fabrication and lays the groundwork for an advanced discretized modeling.