A study of a multi-layered thin film heat transfer gauge and a new method of measuring heat transfer rate with it.

A new method of measuring heat transfer rate with high spatial resolution and fast response is developed to be used in wind tunnels with long flow duration. For the development of the new method a multi-layered thin film heat transfer gauge is proposed. The principle of the sensor is based on measuring the temperature gradient across a thin, heat resistant layer of SiO with two, thin film resistance thermometers on its upper and lower surfaces. These thin films and the heat resistant layer are deposited by vacuum evaporation technique. The design consideration, the accuracy of the sensor, frequency response, and the calibration technique are discussed. The sensor is applied to the measurement of the heat transfer rate in turbulent boundary layer on a flat plate at Mach number 4, Tw/T0= 0.64, and Re=1.4×107, and shows high sensitivity and fast response. It also shows excellent durability.