A novel phase change material-based heat sink with an orthotropic plate to enhance the temperature field uniformity for avionics

In this study, an orthotropic plate arranged at the bottom of the phase change material (PCM) -based heat sink is employed to enhance the temperature field uniformity (TFU) in the heat sink. The performance of the orthotropic plate in enhancing the TFU is numerically studied during the melting process of the PCM. The effects of the orthotropic conductivity (R) are examined at R = 10 Rb, 5 Rb, 0.2 Rb and 0.1 Rb. The configuration including a copper plate is also taken into consideration as a contrast to achieve a more objective and deeper insight. It is found that the orthotropic plate can significantly enhance the TFU by up to 4 times in the PCM regions; it can also narrow down the temperature range in the heat sink region. When the orthotropic conductivity is greater than Rb, it can even benefit in improving the performance of thermal management of the heat sink. Principles about the orthotropic conductivity are drawn and comprehensive evaluations are conducted to guide in designing PCM-based heat sink for thermal management of avionics.