Exploring Hydrophobic and Hydrophilic Surfaces

Mar 29, 2019

by Jean Thilmany ASME.org

Interview conducted by Paul Glanville, PE, Senior Engineer, Gas Technology Institute

The Effects of Frost Nucleation and Growth

Alexander Van Dyke, a senior undergraduate student at Kansas State University (KSU), along with Professor Amy Betz have been working on a project investigating the effects of Hydrophobic and Hydrophilic surfaces, with varying wettability, will affect the formation of frost growth.

In an interview with Alexander Van Dyke, he indicates that, “this concept has implications not only on airplanes, and power transgression lines, but there are certain situations where you want frost to grow.” He went further to say, “There’s a concept of a system out in the desert where they are using frost growing as water collection.”

GLANVILLE: Tell us about your experience. How did you get involved in the Frost Nucleation and Growth research project?

VAN DYKE: I am in my last semester of undergraduate studies. Spending the past five years working towards a degree in mechanical engineering with a dual major in mathematics my degrees at KSU, I knew I wanted to get a master’s degree and get involved in research.

In searching the KSU ME faculty directory, I found Professor Amy Betz. She was working on thermodynamics and heat transfer, which are some of my primary interests. Although, I met with other professors, when I talked with Professor Betz, she was eager to offer me a research position. I could feel her excitement toward engineering. I enjoy being a researcher and I plan to purse a Ph.D. to one day become a professor.

GLANVILLE: Do you think this project is going to be related to your graduate work?

VAN DYKE:  Yes, definitely my master’s thesis. I am going to work on translating our findings into a Lattice Boltzmann mathematical model. Thus far, it has been a challenge to model frost growth due to computational limits and frost formation complexity. I am going to use the surface wettability’s and the surrounding conditions as a parameter, as well as, the thickness of the layers (which are Nanometers thick). Then we will conduct more empirical work to see if the results we find from different surfaces actually match the model.

GLANVILLE: Tell us about the experimental preparation for the work that you have done with some of the surface treatments?

VAN DYKE: The biggest task was building the experimental set up. We had to create a micro channel heat exchanger. We ran ice water through it while running a Peltier heater in reverse; fabricating the materials was quite the process. So far, I personally have not made one of the mixed surfaces. Those have all been Professor Betz. I have been making the plain hydrophobic slides. We take glass slides and we coat them in a 1% OTS to toluene mixture, for about 15 minutes then remove the material with chloroform.

GLANVILLE: Working through your upper division classes and particularly looking forward to the modeling side of things, how has those classes aided you in understanding this work and in turn your class material?

VAN DYKE: Heat Transfer actually worked in reverse, my research helped me understand the course. Aside from that, my undergraduate courses; thermodynamics, machine design and working with heavy machinery in our ISME class has been crucial. It was a lab where we learned machine code and fabricated our own bench vice. Also, being a math major has helped me understand the modeling better.

GLANVILLE: Do you see this work benefiting the marketplace?

VAN DYKE: The biggest one that I see is the aircraft industry. In the past 15 years, there have been over 70 airplane crashes that have been caused due to frost build up. Although they are smaller scale planes typically, it has a big effect; it decreases the lift and increases the drag, the planes stall. If we can prove that these layers do in fact, at least, create a thinner and easier removed frost growth or even mitigate it, then we can integrate that into the design of the wings. Then hopefully, that will decrease crashes, and the same applies pretty much to all of the other systems; decrease the frost growth for specific hydrophobic and hydrophilic surfaces. Refrigeration systems is also major because of the major decrease in efficiency frost creates.

GLANVILLE: Have you spoken with an aviation companies or aeronautic experts?

VAN DYKE: Professor Betz has shared our research findings with potential stakeholders at various conferences. They all think it is cutting edge, necessary research and are very supportive of the work.

GLANVILLE: Do you expect that in order to simulate those conditions at some point you will have to use a wind tunnel?

VAN DYKE: There is a wind tunnel at KSU that we will be able to use for model flight simulation through the aero department.

GLANVILLE: In reaching out to the aero department, have you found any other collaborative opportunities around your research?

VAN DYKE: One of the main struggles is figuring out how to measure the density of the underlying frost layer. At KSU, we have a working nuclear reactor, and so we were thinking about using the Gamma rays, that it pulses out, to get the density. If not, then our mathematics department has a good digital image processing professor who we might be able to work with. We also went interdepartmental to use a SMART Lab.

GLANVILLE: Do you find yourself looking to specialize as you continue in your academic program?

VAN DYKE: I am hoping to specialize in heat transfer at a micro Nano scale. I also find the natural gas industry fascinating.

GLANVILLE: What’s next for you?

VAN DYKE: If I do not pursue a Ph.D., I hope to aid in improving the technique that we use for Shale Gas extraction and promote the natural gas industry. But right now, I am focusing on my Master’s thesis and this frost research. It’s relatively in its infancy--- and I would like to, at least, be a part of developing an overall theory or even just the model. Hopefully, applying the concept to other surfaces and being able to say ‘yes’ frost will form this way on this surface under these conditions.

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