The innovation of an aerodynamic-heat-harvest TEG considering multi-interface contact effect for a high-speed flight vehicle

High-speed flight vehicles generate large amounts of aerodynamic heat during long-duration flights, so the aerodynamic heat harvest based on thermoelectric (TE) conversion is one of the most promising thermal management techniques. In this work, a heat-harvest thermoelectric generator (TEG) is innovatively created and evaluated with the fully consideration of multiple heterogeneous interfaces effect. At first, a TEG including a force-bearing frame, twenty-seven couples of cylindrical TE legs, fifty-four couples of electrodes, two substrates, an insulation layer and two types of heterogeneous interfaces is designed and fabricated to possess the heat-harvest and force-bear functions simultaneously. Secondly, the surface topography of TE legs and electrodes are reconstructed based on the contact-type measurement and W-M function, numerical models of thermal and electrical contact resistances are established and validated by in-direct experimental measurements, and the influences of pressure, temperature and clearance medium are clarified. Thirdly, the TE transfer and conversion processes of the generator is analyzed considering the micro-scale contact resistances; the TE and mechanical performances under the vehicle's typical aerodynamic conditions are numerically and experimentally evaluated, and the maximum voltage and output power of TEG are revealed to be 6.978 V and 12.41 W, respectively.