Spot Conductance Measurement Using Infrared Thermography

The estimation of thermal contact conductance (TCC) across any contacting surfaces is required for the efficient design and safety of mechanical systems. The accurate estimation of heat flux and temperature drop across the interface is crucial for the assessment of TCC. In the present experimental investigation, stainless steel (SS304) is selected as it is frequently used in various industrial applications. A high-temperature experimental facility has been built to study interfacial heat transfer and TCC estimation. The contact spot conductance has been estimated using steady-state measurements in vacuum utilizing surface temperature information from infrared thermography. The primary objective is to determine the effect of contact pressure (1.7, 4.7, 7.7 MPa) and surface roughness (0.49 and 1.64 μm) on TCC at interface temperatures of 300 °C. Infrared thermography technique is applied for better thermal visualization and accurate prediction of interfacial temperature drop. The result depicts that at lower surface roughness, TCC increases more rapidly with contact pressure. Moreover, experimental results have been suitably normalized and compared to the available theoretical models.