Numerical and Experimental Studies on the Vortex Tube Phenomenon

As hydrogen usage increases in the industrial and transportation sectors, it becomes more important to limit waste. Because it is more dense as a liquid, bulk hydrogen is often transported as a cryogenic liquid, at -253°C (-423°F). But unless active cooling is applied (which requires electrical power), the heat load from the ambient environment causes the liquid to boil off and vent to atmosphere, wasting hydrogen. This thesis explores a two-part method of reducing this boiloff rate. The first is the endothermic reaction from parahydrogen to orthohydrogen, available in the boiloff stream. The second is the use of a Ranque-Hilsch Vortex Tube, which separates a source of compressed gas into hot and cold streams without any moving parts. By combining these two into what is called a Heisenberg Vortex Tube, cooling can be provided to the tank without any external power, thus reducing boiloff. Experimental and numerical results are shown for vortex tubes using air. In addition, a monolithic, metal vortex tube was additively manufactured and tested with air, producing significant cooling effect. The developed numerical models are extrapolated for use with cryogenic hydrogen

A Creative Project in Printmaking Dealing With the Production of a Series of Original Prints Using Multiple Plates Printed in Relief and Intaglio Techniques

It was the purpose of this study to explore and develop technical and aesthetic possibilities resulting from the use of multiple plates in printmaking: 1. by relating the content of separate plates through the combination of shape, color and implied narrative qualities; 2. by developing the contour of the total composition as a secondary visual effect of the multiple plates with no limitation as to media, material, or color within the production of the print