A novel temperature based flat-plate heat flux sensor for high accuracy measurement

This paper presents a novel flat-plate heat flux sensor for thermal control systems of airborne electronic equipments and actuators. The sensor consists of a pair of high and low conductivity materials to enable the temperature difference between the heat source and heat sink to be measured by resistance temperature detectors (RTDs) and an auxiliary conditioning circuit. Because high accuracy RTDs are installed on the surfaces of the temperature component and the heat flux can be accurately calculated according to the Fourier conduction law, this sensor can acquire high accuracy measurements. Specifically, this paper details the operating principle and design of a heat flux sensor, discusses methods for improving the heat flux resolution, presents a computational algorithm (with experimentally validation) for a prototype sensor, and demonstrates the application of a flat-plate heat flux sensor as an equivalent physical simulator (EPS) for a nanosatellite. Two design configurations are experimentally compared providing intuitive insights to the effects of the key parameters on the sensor performance. Experimental studies show that the flat-plate heat flux sensor has a sensitivity in the order of 0.001-0.01 K/(W/m²).