A STATISTICAL ANALYSIS OF TEMPERATURE OSCILLATIONS ON A FLAT-PLATE OSCILLATING HEAT PIPE WITH TESLA-TYPE CHECK VALVES

Steady-state, oscillatory temperature signals occurring on the wall of two flat-plate oscillating heat pipes (FP-OHP) – one with Tesla-type check valves (TV FP-OHP) and another without – were analyzed using statistical methods in order to quantify and determine oscillating behavior associated with flow rectification. Using the Expectation-Maximization algorithm, a probability density function (PDF) governing the temperature signal was found to be multi-Gaussian and dependent on heat input and heat pipe region for both FP-OHPs investigated. Results further indicate that the inherent flow rectification within the TV FP-OHP provides for an evaporator temperature signal with a less heat-dependent, higher-kurtosis PDF and, at higher heat inputs, a higher: Pearson correlation coefficient and Shannon entropy. These results provide a unique means to quantify the pseudo-random feature of oscillatory temperature occurring on an OHP.