The effect of heat pipe transverse spacing under forced convection-to-natural convection flow conditions

The rate of heat transfer and friction factor of heat pipes with transverse spacings between 44mm to 52 mm was numerically investigated and experimentally tested. A total of 19 wickless copper heat pipes with water as the working fluid were used in this study. A forced convection-to-natural convection setup was used on the heat pipe evaporator to condenser cycle. The numerical simulation showed that the rate of heat transfer increases in line with a transverse spacing increase until it reaches its optimum spacing. A reduction in flow movement (mechanical power) is required for larger transverse spacings due to lower flow resistance caused by the heat pipes. The results from the study show that the heat flux can improve by up to 14% by variation of the transverse spacing. The heat pipe optimum transverse spacing was determined in this study at the spacing to diameter ratio of 3.1.