Date of Award

2012

Degree Type

Thesis

Degree Name

Master of Science in Mechanical Engineering and Applied Mechanics

Department

Mechanical, Industrial and Systems Engineering

First Advisor

Zongqin Zhang

Abstract

An experimental investigation on pulsating heat pipes with dual-layer and single layer configurations was conducted in order to determine the effect of the heat transfer and overall system performance given a constrained dimensional heat source with a dual-layer arrangement. The dual layer configuration is an assembly of two pulsating heat pipes of equal measurement connected with a cross linking tube, allowing them to operate using the same working fluid. The dual-layer system was compared to the base single-layer system on several different accounts. These included start-up time and temperature, the average/minimum/ and maximum evaporator temperature during steady state operation, the overall heat transfer capability, and the overall thermal resistance of the system. These requirements were reviewed at different fill ratios: 0%, 25%, 75%, and 90%. The dual layer pulsating heat pipe system (DLPHP) attained the lowest thermal resistance of 0.12 ºC/W at a fill ratio of 75%, while also maintaining an average evaporator temperature of 85 degrees Celsius at an input power of 120 Watts. The single layer pulsating effect, however, was attained at 110 degrees Celsius at its most efficient fill ratio of 50% and a thermal resistance of 0.85 ºC/W and input power of 120 Watts. It was concluded that the dual-layer system exposed to the same input power and area achieved an overall increase in performance with respect to start-up time and temperature, showing start-up oscillation temperatures as low as 73 degrees Celsius, compared to the 88 degrees Celsius required to observe temperature oscillation in the single layer pulsating heat-pipe (SLPHP).

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