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Ashley Macner wins 1st Place in the Enabling Technologies Poster Competition

Wednesday, April 24, 2013

Ashley Macner wins 1st Place in the Enabling Technologies Poster Competition at the 28th annual meeting of the American Society for Gravitational and Space Research.

Her poster titled, "Dropwise Condensation on a Cold Gradient Substrate."

Abstract: Distributions of drops that arise from dropwise condensation evolve by nucleation, growth, and coalescence of drops. In order to design effective surfaces for large-scale dropwise condensation, an understanding of how the surface functionalization specifically affects drop growth and coalescence is needed. The long term technological goal is to be able to propose a set of design conditions to NASA to help them achieve maximum heat transfer rates under microgravity conditions in their management of waste heat generated from electronics and habitable environments. Transient dropwise condensation from a vapor phase onto a cold and chemically treated surface is reported. The surfaces were treated to deliver either a uniform contact-angle or a gradient of contact-angles by silanization. The time evolution of drop-size distributions and number-density is reported. For a typical condensation experiment, the drop distributions advance through two stages: an increase in drop density as a result of
nucleation and a decrease in drop density as a result of larger scale coalescence events. Because the experiment is transient in nature, the shape of the distribution can be used to predict the number of drop generations and their stage of development. Preliminary results for gradient surfaces will be discussed and compared against observations of behavior on uniformly coated surfaces.

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