Week 5: April 28, 2016

Greetings Heat Pipe Aficionados!
This week marks a rather impressive jump in progress for the HamPipe. Last weekend, Karen, Noelle, and Mr. Kownurko worked to create a working prototype, named Harold, for the eventual deliverable heat pipe. (Ben would have been there as well, but he had to be at home for Passover). The entire construction process took somewhere between 4 and 5 hours, and there will be a page elsewhere on the blog dedicated to chronicling the step by step directions. The production went extremely well. There were several parts involved between fittings, two different copper tubes, and the braided stainless steel wick material. Though the group was awake for most of Saturday night, we were eventually able to create a working heat pipe.

Karen drilling holes into the inner copper tube. 

Noelle soldering under the careful supervision of Mr. Kownurko.

On Sunday, the group ran several different tests. The first set of tests involved using water as a heat transfer fluid. Later tests involved methanol and acetone as the heat transfer fluids, as we were able to drain the heat pipe through the series of valves on the top. Finally, we tested a higher volume of water in the heat pipe (jumping from 20 mL to 25 mL). There were some setbacks with the testing rig, one of which involved the vice (used to hold the heat pipe at a fixed angle next to the heat source) working as a heat sink. To combat this, we added two pieces of oak wood, one one either side of the heat pipe, which isolated it from the metal of the vice. The rig wasn't perfect, and though we made sure to create a vacuum within the heat pipe during testing, there is always a risk of contamination of the heat transfer fluid inside the tube. For each test, we took temperature at two different points on the heat pipe (close to the heat gun, and further away from it), as well as pressure readings every thirty seconds, and documented until we reached 30 psi. Though we were fairly certain that our solder joints could hold up to 60 psi, we weren't particularly willing to risk the joints failing and spewing 200 degree (F) liquid across the work space and the group itself.

A round of testing: Karen read pressure out to Noelle every 30 seconds, as Noelle recorded both the pressure and the 2 different temperatures on a chart.

Throughout the tests, the group decided that for right now 25 mL of water was the best fit for our heat pipe for several reasons. The first reason is that the water was the least volatile, and maintained a steady pressure that did not pose too much risk to the solder joints. Also, acetone and methanol heated up more quickly initially, but because of the pressure building up so quickly, they were not able to reach as high of a heat as the water. In case you had forgotten, the goal of this particular heat pipe is to be used in cooking (specifically ham), so water also provides a more safe heat transfer fluid. Though there is very low risk of the fluid actually leaking out, during food preparation it is often better safe than sorry. Finally, in tests, the 25 mL of water managed to circulate so well that the temperature at the top of the heat pipe (further from the heat source) was actually higher than the temperature closer to the heat gun, which was pretty amazing to see. The group exited the weekend with an incredible amount of data to input into excel, graph, and analyze, as well as a working heat pipe. This week in lab was therefore mostly dedicated to formatting graphs and charts, and discussing future plans. One option on the table is purchasing a 25-75 mix of ammonia and water, which is likely to be less volatile than the acetone and methanol, but more efficient than water alone. Other discussions centered around whether to build another heat pipe with regular screen instead of braided steel as the wick, or whether to make a final heat pipe the same way, but cap it instead of having the series of valves on the top, or simply cap the existing prototype. The week ahead will contain a good amount of time spent formatting graphs, and creating the portion of the blog which lays out the heat pipe creation process. Ben has also begun working on the draft for the final report, which is due during week 7.

A piece of plain copper tubing, being tested as the baseline on the rig using a vice and a heat gun.

Week 4: April 21, 2016

Another day, another exciting opportunity to work on research for this team's HamPipe. This weekend will contain an impressive amount of time spent on fabrication of the team's initial heat pipe, or heat pipes as the case may be. This means that the group is under pressure to finish at least most of the necessary research during class this week. It is also important for the blog to show real progress before the start of class next week. Both the acetone and methanol came in during  the past week, so Karen and Noelle brought them into class. Fabrication will be at Noelle's house in West Chester, so the group discussed logistics (Ben won't be able to attend, so Karen and Noelle will be the main fabricators, at least for this round). Beyond that, the group set themselves on specific tasks. Karen worked on creating heat charts for the different chemicals being used in the heat pipe (water, methanol, and acetone). Ben, while still afflicted by a dreadful bout of the flu, worked to fill any gaps in research regarding materials being used, different heat pipe theories, and really anything else that might be missing from the group's knowledge base. Noelle continued working on the blog, both completing the week's blog entry, and organizing and filling in the research links section, as well as adding to the background information tab. Overall, it was a quiet week, each group member mostly keeping to themselves in an effort to finish up all required research and background before the actual fabrication was set to begin. 

Week 3: April 14, 2016

Dear Loyal HamPipe Enthusiasts,
It's an exciting day in ENGR 103, Group HamPipe gained a new member: Cameron Knickerbocker. The group was overjoyed at the prospect of having another person to join this adventure, but did not let the excitement distract them from their diligent working. Though sleep deprived, Ben and Noelle steadily produced several IEEE references to add the the blog, and discussed plans for fabrication. Karen took Cameron under her wing, explaining the plan such as it is for the HamPipe, and the basics of a heat pipe in general. She also added an impressive amount to the CAD creation of the heat pipe; a task which passed to her because Ben realized that along with other engineering ventures, he also hates CAD. Noelle spent a good chunk of time adding to the blog, so as to keep both it and it's readers updated. She also worked on sections beyond the weekly updates, because at this point a majority of the research has been gathered in a Google Doc, and needs to be re-compiled in the blog. All of the parts have been ordered, and the basic heat pipe plans have been penned and await with bated breath the weekend of fabrication. Speaking of fabrication weekend, Group 7 solidified their plans for getting together at Noelle's house and creating their first HamPipe. All told, this week has been fairly productive, though it was made slightly less productive because none of the parts had yet arrived, so they could be neither examined nor tested. Stay tuned for further updates.

Update: April 28, 2016 
The group has suffered the tragic loss of Cameron, and has now reverted back to the original members: Karen Chu, Noelle Kownurko, and Ben Teperov.

The new group. From left to right: Karen, Cameron, Ben, and Noelle. All still thrilled by the prospect of HamPipes

Week 2: April 7, 2016

Group HamPipe returned to the scene of their design lab planning. The weather was mild, though slightly overcast, and the group was ready for some intense engineering. After working all week on both blog and proposal, everyone was well-versed in the various designs and inner-workings of heat pipes. The trio decided to take on the divide and conquer method. Karen worked on finding somewhere to buy methanol for testing, since it was the only material the group did not already know where they could purchase. Meanwhile, Ben set to work using Autodesk's Fusion 360 to make a 3-D model of the group's design for the superior heat pipe. Noelle, on the other hand, could be found typing away enthusiastically on the group's blog, making certain that anyone curious would be well-informed on the group's activities, as well as adding to the various tabs included in the blog. One aspect of this was sorting through the group's research, grouping it, and generating citations to add to the resources page. During discussion of the design of the heat pipe, the group realized that there would be an issue of conductivity between the fins (planned to be made of stainless steel mesh) and the copper tubing, so they switched their design to include fins made of thin copper plating instead.
Ben experienced a few setbacks on the Fusion 360 modeling, but he generally made very useful progress and was optimistic about the outcome of his work. Once Karen was finished shopping for flammable liquids, she created a schedule for the group's activities over the entire 10 week period. Set upon their tasks, team HamPipe worked diligently through the two hour time period, and vowed to stay in touch during the coming week so that upcoming tasks would not pile-up and threaten to overwhelm them.

 

Figure 2: The beginning of the Fusion 360 model of the HamPipe