Numerical investigations of fin efficacy for phase change material (PCM) based thermal control module

Abstract

Solid-liquid phase change process has large isothermal heat absorption capacity. Hence, phase change materials (PCM) has potential to achieve thermal control of electronic devices during pulsed heat load generation. Usually, PCM has a disadvantage of low thermal conductivity. Hence, fins are used to improve thermal conductivity of PCM module. Numerical investigations are performed to find the most effective fin configuration which would limit critical temperature (Tcr) of thermal control module (TCM). The important fin parameters under consideration are size, number, shape and % mass of fins. Six different fin geometries are examined: rectangular, triangular, circular-prisms and rectangular, triangular, circular-frustum pyramids. Numerical model is validated with previously reported experimental results in literature. Results show that Tcr decreases as number of fins increased from 9 to 100 and then further reduction in Tcr ceases. For respective % mass of fins, Tcr values for all prism geometries are lower than for all frustum geometries. Considering an extended active period up to 14 min, lowest Tcr values are achieved for 20% mass of fins. It is observed that thermal performance of TCM is highly influenced by area enhancement ratio (Af) which is highest for triangular prism geometry leading to lowest Tcr.