Experimental analysis and FEM simulation of finned U-shape multi heat pipe for desktop PC cooling

This paper presents the performance analysis of a finned U-shape heat pipe used for desktop PC-CPU cooling. The experiments are conducted by mounting the system vertically over a heat source situated inside a rectangular tunnel, and force convection is facilitated by means of a blower. The total thermal resistance (R-t) and heat transfer coefficient are estimated for both natural and forced convection modes under steady state condition, by varying the heat input from 4W to 24W, and the air velocity from 1 m/s to 4 m/s. The coolant velocity and heat input to achieve minimum R-t are found out and the corresponding effective thermal conductivity is calculated. The transient temperature distribution in the finned heat pipe is also observed. The experimental observations are verified by simulation using ANSYS 10. The results show that the air velocity, power input and heat pipe orientation have significant effects on the performance of finned heat pipes. As the heat input and air velocity increase, total thermal resistance decreases. The lowest value of the total thermal resistance obtained is 0.181 degrees C/W when heat input is 24W and air velocity 3 m/s. The experimental and simulation results are found in good agreement. (C) 2011 Elsevier Ltd. All rights reserved.