Investigation on a gas-atomized spray cooling upon flat and micro-structured surfaces

The high integration and vigorous microminiaturization has led to an exponential growth in the required dissipated heat flux of the on-board electronics (10²–10³ W/cm²). However, the accepted working temperature of common electronics is recommended to be below 85 °C. Current spray cooling using the pressure nozzle has toughed its bottleneck. Spray cooling using the gas-atomized nozzle for electronics cooling has not been a focus in the past. Considering the easy availability of the high-pressure air in an atmospheric flight system, a gas-atomized spray cooling system can be adopted feasibly. This paper provides a ground-based experimental investigation of the gas-atomized spray cooling using various micro-structured surfaces and a flat surface. Cooling performance of different surfaces and nozzle inlet temperature of coolant are provided and discussed. A cooling correlation of gas-atomized spray cooling upon micro-structured surfaces is provided with a relative error within ±9%. In addition, a comparison of spray cooling performances using the gas-atomized nozzle and pressure nozzle is organized. Results show that the gas-atomized spray cooling possesses a huge superiority where a heat transfer coefficient can be enhanced by 234%. Mechanism of the enhanced gas-atomized spray cooling is offered as well.