Study of flow characteristics of an oscillating heat pipe

Highlights: • An experimental test system was developed. • The theoretical model was proposed to predict the flow pattern. • The OHPs were proposed to study their heat transfer characteristics. • The dimensionless temperature was proposed. -- Abstract: The objective of this work is to study the heat transfer characteristics and predict the flow pattern of an oscillating heat pipe (OHP). In the present study, two-dimensional OHP and three-dimensional OHP were designed and the temperature oscillations of the OHPs were experimentally studied for applications in electronics cooling conditions. The mathematical equation, obtained by analyzing the driving force acting on the system, is derived to evaluate the flow characteristics. The model include the dimensionless temperature and the flow factors. The dimensionless temperature is characterized by the vapor temperature, while the flow factors is described by the thermodynamic properties and transport properties. The mathematical model was modified to study the OHPs. The OHPs were studied using both experimental method and theoretical method. The comparison results suggested that three periods can be defined to study the flow regime.