Here is the abstract you requested from the Thermal_2018 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Out-of-plane bends' effect on the thermal performance of flat plate oscillating heat pipe|
|Keywords: oscillating heat pipes, heat sink, thermal management|
|The objective of the research presented herein is to estimate and then empirically measure the temperature rise inside a flat plate oscillating heat pipe (FP-OHP) before and after making out-of-plane bends. Unlike conventional wick-based heat pipes, FP-OHPs can passively transfer hundreds and even thousands of watts through relatively thin cross- sectional areas. Further, FP-OHPs made from malleable envelope materials such as annealed Aluminum or Copper can be bent post-manufacture into three- dimensional shapes with relatively tight bend radii (e.g., 3x their thickness). This paper is most interested in “out-of-plane” bends where a FP-OHP’s internal micro- channels run the x-y plane before the bend is made, but after the bends are made the micro-channel run in the y-z plane. These out-of-plane bends allow the FP-OHP technology to be integrated into products or systems where complex, three-dimensional and tortuous heat transfer pathways are needed but where the space available for such pathways is limited. To evaluate the effects of out-of- plane bends on thermal performance of an FP-OHP, the researchers propose to present a Copper (Cu) FP-OHP sized at approximately 1” x 10” x 0.08”. The FP-OHP will be attached to a 1 square- inch heat source (evaporator) and 2 square-inch heat sink (condenser). The FP-OHP will be tested in its un-bent or planar form under a variety of gravity orientations. Next, the same FP-OHP will be bent with an approximate 0.25” inner radius and re- tested under the same conditions as before such bend was made. Finally, three additional bends of approximately 0.25” inner radius each will be made to the FP-OHP to form a “top-hat” shape and re-tested a third time under the same conditions as the unbent and one-bend FP-OHP. Mechanical drawings of the FP-OHPs external dimensions will be presented along with photographs of the FP-OHPs before and after the bends are made. In addition, time versus temperature plots will be presented for the different tests conducted to support the thermal performance claims. A prediction of the bends’ effects on the pressure drop (and thus temperature rise in the saturate working fluid within the oscillating heat pipe) will be compared to the experimental findings. Calculations supporting such pressure drop will be presented as well as the calculated pressure drops from the actual temperature rises observed during the tests described above. Finally, recommendations for future research, develop and commercial applications will ensue.|
|Joe Boswell, CEO
ThermAvant Technologies, LLC