Numerical method for thermal response characteristics of metallic honeycomb sandwich panels under aerodynamic heating

A numerical method was presented for transient heat transfer processes in honeycomb sandwich panels used in metallic thermal protection systems (TPS) under aerodynamic heating. A one-dimensional heat transfer model combined with conduction and radiation was established for a honeycomb sandwich panel which was modeled by a three-layered plate structure. Monte Carlo method was used to model the radiative transfer process between honeycomb inner surfaces, and finite volume method was used to solve the energy equation of the coupled transfer processes. Thermal response was numerically predicted for a particular right hexagonal honeycomb sandwich panel under aerodynamic heating, with temperature dependent thermal properties of metal and air. Numerical results were compared with those from experiment in materials. The consistency between the numerical and experimental results in temperature on both honeycomb panel surfaces consolidated validity and effectiveness of the method presented. In addition, validity of using equivalent thermal conductivity given by Swann and Pittman correlation in transient heat transfer processes was reconsidered. Results show that significant error exists in temperature on both surfaces while using the correlation instead of combined model presented, with much higher temperature at the heated surface and lower temperature at the unheated one. The temperature difference between heated and unheated surface can be 2.4 times at most as that given by the combined model.