Thermal Shock Resistance of Ultra-High-Temperature Ceramics Under Aerodynamic Thermal Environments

The Effects of Constraint, Size and Aspect Ratio on Thermal Shock Resistance of ZNS Wave-Transparent Ceramic in its Actual Service

“…[24,25]) Figure 4 (unilateral simply supported and unilateral clamped support are constrained on opposite sides, taking one fourth of the model into consideration, they are constrained on one side; both simply support and clamped support are constrained on the middle line of the side face, clamped support mains that the middle line is fixed constraint, while simply support mains that the middle line can only move along the line) reflects the relationship between critical rupture temperature difference (the values of critical rupture temperature difference in this paper are all taken from the upper surface which is imposed with heat flux) and the heat transfer condition when ZnS plate which only imposed with surface heat flux at its upper surface is subjected to different forms of constraints. When the heat transfer condition is relatively small, the overall trend of the curves changes from monotone decreasing to monotone increasing gradually as the increase of constraint; when the heat transfer condition is large, the curves tend to become flat, and the TSR of ZnS plate is not sensitive to the change of heat transfer condition and constraint.…”

“…In addition, although the second TSR parameter R' can reflect both mechanical properties and the thermal conductivity of materials, it still can't characterize the TSR correctly in many situations [18,28,29]. So the heat transfer condition and critical rupture temperature difference are used to characterize the TSR of ZnS plate in the calculation [24,25].…”

“…(10) doesn't need to calculate the infinite series and further verify its convergence, it's relatively convenient for calculation when compared with Eq. (9) [24,25]. In this paper, according to the specific thermal shock process, the Eq.…”

“…Before the temperature of the insulated lower surface being changed, the model of the semi-infinite solid can also be used for the transient temperature field of the plate [24,25]. The analytical solution of the semiinfinite solid, which is initially at a uniform temperature T 1 and imposed with constant surface heat flux q s at its upper surface, is obtained in [27]: 1 e x p ( )…”

“…Therefore, improving the TSR of ceramic has been one of the most important focal points in the ceramic field [19][20][21][22][23]. In order to study the influences of constraint, size and aspect ratio on the critical rupture temperature difference of ZnS wave-transparent ceramic subjected to aerodynamic heating and pneumatic pressure, the heat transfer condition and critical rupture temperature difference [24,25] were used to characterize the TSR of ZnS plate in this paper. The effects of constraint, side length and aspect ratio in case of different pneumatic pressures were focused on, so as to give effective suggestion sand provide both theoretical basis and technical guidance for the design and application.…”