Investigations on Fluid Flow and Heat Transfer Characteristics of Closed Loop Pulsating Heat Pipe

Abstract

The advancements in the field of electronics has led to the development of modern newlineday computers and electronic gadgets. These devices have the capability of high speed data newlineprocessing and hence can provide reliable information in a very short time. The high speed newlinedata processing is facilitated by the large scale use of miniaturized IC chips with high newlinepacking densities. Although, high speed data processing is an obvious advantage realized, newlinethe large scale heat evolution is a major drawback of such electronic devices. Presently, the newlinechip heat flux level ranges between 40 to120 W/cm2 newline.It is expected to increase to 200 W/cm2 newlinein the next few decades. Hence, thermal management of electronic devices is inevitable and newlineassumes top priority in the field of electronic product development. With a proper thermal newlinemanagement, the permanent damage or premature failure resulting from high heat newlineevolution can be prevented. newlineSeveral cooling methods including air cooling, liquid cooling etc. are used in the newlineelectronic industries to cool the electronic cabinets. One of the devices used to remove the newlineheat effectively from the electronic cabinet are the heat pipes. To overcome the inherent newlinelimitations of the conventional heat pipe, a new type of heat pipe called the Pulsating heat newlinePipe (PHP) or Oscillating heat pipe (OHP) was first proposed by Akachi in the year 1990. newlineThe PHP consists of small diameter tubes bent in a serpentine manner to form meandering newlineturns. One end of the PHP forms the evaporator which is heated and the other end the newlinecondenser is cooled. In between evaporator and condenser is the adiabatic section which newlineconveys the heat from the evaporator to the condenser. A working fluid circulates newlinecontinuously between the evaporator and condenser by changing its phase from liquid to newlinevapor and vapor to liquid in the evaporator and condenser respectively. The heat transfer newlinein a PHP takes place by utilizing both the latent and sensible portions of heat. Although, newlinevarious designs of PHP are available, the most po