Week 9

May 26, 2016

In recent weeks, we had made great progress towards completing all of the refinements to our design.

To start week 9, we sat down as a group and gathered all of our data and results. We recognized that trials 1 and 2, where the fluid level was constant but the wick size was changed, would provide comparable data to conclude which wick (larger or smaller) allowed for a more efficient and effective heat pipe.

Trial 3 was a success as well, as we used the more effective wick and tinkered with the fluid level within the pipe. By reaching an equilibrium during which the temperatures were effectively equal, we had refined our design to the point of achieving success. We used this trial to compare to the first two, to show how both wick size and fluid levels had an impact on the overall efficiency.

After we had gathered our data and compared results, we used various equations to describe the relationships present. These equations are presented with more detail under the equations tab at the top of this page. In the end, after accounting for the diameter of the screen wires and the width of the holes in the screen, we were able to calculate values of wick permeability for each screen.

By simplifying known equations, we derived a proportionality between wick permeability and fluid friction. We showed that fluid friction was directly related to wick permeability. Since the 16 hpi wick had a greater permeability, it therefore exhibited greater internal fluid friction. A greater amount of friction can slow down the movement of condensed water, and would thus create a less efficient heat pipe. This ultimately agreed with our results from trials 1 and 2, which showed that the 16 hpi was less effective.

The rest of week 9 was spent creating and practicing our final presentation. A final copy of this presentation will be available below after it is finalized. Through much practice, this presentation will allow us to tell the story of our project, what we learned, and how it could have been improved.

On the whole, we feel as if we were very successful in the goals we set out to achieve. Through a three week literature study, we were able to find the information needed to choose the best materials for the project. This literature study also allowed us to identify the gaps in prior research, such as testing with cheap metal mesh wicks, and focus our analysis accordingly. Over the course of many weeks of refining and changing our heat pipe, we ultimately landed on an effective design that could be used and applied in a real world cooling application. In the end, we were able to establish a relationship between wick size and effectiveness of heat transfer, and had extra time to further refine the fluid levels within the pipe. By completing all of the goals we set out to achieve, as well as creating a working prototype, we feel that the project was an overall success.

We look forward to outlining our trial 3 results in the final report and presenting our work to students and faculty in week 10.

-- Alec, Tran, Matt, and Shjon