Static and dynamic errors in heat flux measurements

Systematic errors occur during heat flux measurements due to the design and construction of the heat flux sensor. The presence of the sensor alters the original structure of the test article, often the sensor's additional thermal resistance distorts the temperature and flux field, and its thermal mass affects dynamic response. The response of heat flux sensors depends on the nature of the thermal interaction between the aerothermodynamic flowfield and the solid in which the sensor is installed. Static errors are presented in a dimensionless form for the case of convective flux conditions on the surface. The effect of the type of boundary condition and temperature levels are discussed. Characteristics of the transient response of flux sensors, like 'overshooting' under various conditions are analyzed by numerical simulation.