Thermal management of electronic equipment in thermal shock conditions is necessary to prevent device failure and reduce efficiency and increase their useful life. In the present research, the effectiveness of using an ultrasonic field to manage the thermal conditions of a heat sink containing phase change material exposed to cyclic thermal shock is numerically investigated. The performance of the system is evaluated over 2000 s. In the first 1000 s, a constant heat flux of 30 W/cm2 is applied to the bottom of the heat sink, while in the second 1000 s, 5 thermal shocks are applied to the bottom of the heat sink, each lasting for 100 s. Four different values for the shock heat flux (60, 90, 120, and 150 W/cm2) and three different transducer powers (15, 30, and 60 W) are considered. The results indicated that for shock heat fluxes of 60, 90, 120, and 150 W/cm2, the maximum CPU temperature in the absence of an ultrasonic field reaches the 90 ◦C safe operating threshold within 1815, 1615, 1450, and 1405 s, respectively. However, when the ultrasonic field is applied, the maximum temperature of the system consistently remains below 90 ◦C.
