Executive Summary : | In the last two decades, an exponential increase in the heat dissipation rates coupled with rapidly falling sizes, have made thermal management extremely challenging for electronic devices. As a result, there is an ever-increasing demand for efficient cooling techniques. The use of phase change material (PCM) based heat sinks are gaining importance in electronics cooling due to their high latent heat storage capacity to maintain the electronic device at the safest temperature. The PCMs are however, crippled with poor thermal conductivity ( less than 1 W/mK). In view of this, different types of conducting paths have been explored to overcome the thermal resistance offered by PCM and to enhance the charging and discharging rates. In general, the operation of electronics is highly transient. However, the design and characterization of a thermal management system follows a full heat duty cycle approach which is divided into two parts, one is charging process and the other is discharging process. In literature, the investigation of finned heat sink with finned heat pipe has not been explored adequately for establishing its influence on the charging and discharging time. The present proposal aims to develop a novel hybrid heat sink with the systematic joining of the finned heat pipe in a PCM-based heat sink. The heat pipe is a passive heat exchanger having high thermal conductivity and can transfer high heat flux to a greater distance. Hence, its applicability in PCM based electronic thermal management is anticipated as a novelty. The PCM based finned heat sink without heat pipe will be explored first experimentally and numerically for establishing its thermal performance under varying PCM fill ratio, different types of PCMs, number of fins, and heat load. In the second stage, heat pipe (bare/finned) characterization will be conducted experimentally under forced and natural convection. The calculated heat transfer coefficient value will be used as boundary condition for the numerical model. Finally, the finned heat sink with heat pipe will be systematically joined and examined for thermal performance.The proposed hybrid heat sink will be a promising solution for thermal management where heat dissipation rates are not continuous. |