Thermal conductivity of chalcogenide material with superlatticelike (SLL) structure is investigated using the 3ω method and the molecular dynamics method. Both the measured and calculated results show that the thermal conductivity of SLL is lower than those of conventional chalcogenide materials and will decrease to a minimum as the number of interfaces increases. The Raman spectrum is introduced to study the phonon behavior of SLL and the “phonon mode vanishing” is proposed to explain its lower thermal conductivity. Finite-element analysis and phase change memory cell testing confirm the enhancement of cell performance for SLL with minimum thermal conductivity.

To study transpiration cooling problems, an analytical solution of the local thermal nonequilibrium (LTNE) model with the second or third boundary conditions is presented. This solution is obtained through neglecting the thermal conduction of the fluid coolant in porous media. By the analytical solution, two problems are investigated. At first, the parameters which influence transpiration cooling effects are analyzed, and the analysis indicates that the cooling effects are dominated by coolant mass flow rate, the Biot number at the hot surface of porous plate, and the Biot number in the pores. Second, the error caused by the assumption of the local thermal equilibrium (LTE) model is quantitatively discussed, and the variation trend of the LTE error is analyzed. Based on the analytical solution and the error analysis, a quantitative criterion to choose the LTNE or LTE model is suggested, and the corresponding expression is also given in this paper.

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Experimental and numerical investigations are conducted to understand the features of the fluid dynamics within double-wall film-cooled configurations. Based on the similarity principle of the Reynolds number, a large-scale similar configuration made of transparent material is used as specimen, and the fluid velocity distributions over several typical cross sections within the specimen channel are captured by a particle image velocimetry (PIV) system. The experiments are carried out at a density ratio of fluid medium to tracer particle 1.05. The flow features are respectively calculated by different turbulence models and numerical grids. To confirm turbulence models and numerical grids, the numerical results are compared with the experimental data obtained by the PIV system. Through the comparisons, recommendations have been made with regard to the best model and numerical grid which best predict such velocity fields. The influences of inlet Reynolds numbers and the geometrical device of the double-wall film-cooled configurations on the features of flow field are numerically simulated by the recommended model and grid. The simulation results predicate that the flow features are mainly dominated by the geometrical device, the inlet Reynolds number can only result in a magnitude change of velocity fields, and this change is almost linear. This is the first part of the entire investigations on the double-wall film-cooled configurations, and the objective of this part is to confirm a suitable mathematical model and numerical grid for describing the flow features. In the next part, the overall heat transfer characteristics of these configurations will be studied.