ESTIMATION OF TRANSIENT CONTACT HEAT TRANSFER BETWEEN CURVILINEAR SURFACES BY INFRARED THERMOGRAPHY MEASUREMENTS
Accurate prediction of thermal contact conductance (TCC) is essential in the critical fields of nuclear power plants, microelectronics, automotive and aerospace industries. Apart from flat-flat contacts, heat transfer applications/components also form curvilinear surface contacts. Transient contact heat transfer often occurs across curvilinear surface contacts. Conventional techniques of TCC measurement generally involve use of intrusive method of temperature measurements. Intrusive measurements of temperature are known to give biased data. Inverse heat conduction problems (IHCPs), related with the estimation of unknown boundary condition, are also extremely prone to errors in experimental measurement therefore it is important to generate high quality experimental data to get the reliable IHCP solution. In this current work, transient TCC across different curvilinear surfaces have been estimated using an non-intrusive technique. Infrared thermography (IR) technique has been implemented to acquire transient temperature distribution of two bodies in contact. Transient temperatures have been used to estimate transient heat flux passing through the contact by solving the related IHCP. TCC is calculated by using estimated interfacial heat flux and measured temperature drop at the interface. Very promising and insightful results have been obtained by implementing IR technique in TCC estimation. This experimental approach shows that how IR technique can be a better option to correctly estimate thermal contact conductance using surface temperature data of two bodies in contact.