Nanofluid enhancement of mineral oil and thermal properties instrument design [thesis]

Eli Wilborn
ii ACKNOWLEDGEMENTS I would like to thank my thesis advisor, Dr. Willing, for the continued direction and support for the entirety of my thesis. He has been very instrumental in the direction of this project and I am very grateful for his help. I would like to thank Dr. Watters and Dr. Thompson for taking the time to sit on my thesis committee. I would also like to thank my family and friends for their support. iii ABSTRACT There are two purposes of this research, to design and build a heat
more » ... nd build a heat transfer cell that could accurately calculate heat transport coefficients of various fluids and to determine if the increased heat transfer capabilities of nanofluids can be applied to cooling transformers by using the heat transfer cell to measure the enhancement. The design and construction of a heat transfer cell that could accurately calculate heat transport coefficients of various fluids was successful. A heat transfer cell was built and tested on several fluids to confirm the accuracy of the design and the experiments. Three fluids were successfully tested overall for their thermal conductivity values, and one fluid was tested for its convection coefficients in the heat transfer cells. Values for the thermal conductivity and the convection coefficients were obtained during this experiment that agreed with commonly accepted values for the testing fluids. The average value for the thermal conductivities for mineral oil of the first design in the ¼" diameter cell is 0.15 2 , and agrees well with the commonly accepted values of mineral oils. The value commonly accepted value of thermal conductivity for mineral oil is 0.14 2 at 25°C, the first heat transfer cell yielded a thermal conductivity value of approximately 0.16 2 at roughly 25C. The heat transfer cell was also used to calculated convection coefficients of mineral oil, and values were obtained within the limits for natural convection according to Incropera, contributing more to the validity of the results from this heat transfer cell. iv A second heat transfer cell was designed to determine the thermal conductivities of more thermally sensitive fluids, offering a wider range of materials that can be tested. The second design places the thermocouples directly at their assumed position of the wire and the wall temperatures for calculation purposes, yielding more accurate results and can therefore more accurately calculate the thermal conductivities of various fluids. The second design calculated a thermal conductivity of water to be 0.59 2 , while the commonly accepted value is 0.58 2 , which is well within a tolerable range of error to accept this value as accurate at the experimental conditions. This heat transfer cell also calculated the thermal conductivity value for AMSOIL synthetic motor oil to be 0.12 2 and 0.10 2 for mineral oil, both of these values are within the expected ranges of thermal conductivity for oils.
doi:10.18297/etd/1568 fatcat:7ychbl2k3nagtbpyz5rze4wrvy