Numerical Analysis of Dual-Phase-Lag Heat Transfer in a Micro-Scale Thermal Barrier Coating With an Interfacial Resistance

Microstructural effects on heat transfer in a thermal barrier coatings system subjected to a pulsed surface heating is presented in this paper within the framework of dual phase lag heat conduction model. The effects of thermo-physical properties on the energy transport for the simplified two-layered thermal barrier coating and substrate system (TBC-substrate system) are presented. Interfacial thermal resistance is specified as a function of temperature differential on both sides of the imperfect thermal contact. Due to the difference in properties between the two dissimilar materials on both sides of the interface, a strong nonlinear interfacial boundary condition is introduced into the problem. A robust numerical scheme, named Mean Value Finite Volume Method (MVFVM), which is capable of solving conservation equations, is used to analyze the present problem. Results show that the lagging thermal behavior is affected by the thermal properties of the padding material (substrate) and the thermal resistance at the interface. Furthermore, for low values of thermal interfacial resistance (h ≥ 1000), and a given TBC material, the interfacial temperature difference approaches the perfect thermal contact condition when the thermal pulse propagates towards a substrate material with low thermal conductivity value. The results also indicate that the thermo-physical properties of substrate material have more pronounced effects on the temperature distributions than heat flux and temperature gradient lagging parameters.