Thermal Distribution in Hypersonic Leading Edges — 2D TransienT Numerical Analysis
Hypersonic vehicles traveling at speeds exceeding Mach 5 experience severe aerodynamic heating concentrated at their leading edges, particularly at the stagnation point, the region of maximum heat flux. Without an effective thermal management strategy, these extreme temperatures can compromise structural integrity and damage interior components. This project investigates the thermal behavior of a heat-pipe-based Thermal Protection System (TPS) designed to redistribute heat away from the stagnation point to cooler regions of the vehicle, reducing dangerous hot spots and thermal stresses.
A 2D transient heat-conduction numerical model was developed for a wedge-shaped leading-edge geometry. The physical domain was transformed into a uniform rectangular computational domain using a linear coordinate mapping, allowing standard finite difference techniques to be applied consistently across the non-rectangular geometry. Two numerical formulations were implemented and compared: an Energy Balance Method and a Finite Difference Method (FDM) using Gauss-Seidel Successive Over-Relaxation (SOR). Both approaches solved the governing heat conduction equation implicitly, enabling larger time steps than explicit schemes, though conditional stability constraints persisted due to nonlinear material behavior.
Boundary conditions were carefully defined to reflect the physical problem: an aerodynamic heat flux of 460 W/cm² was applied at the stagnation region; adiabatic conditions were imposed on the side walls; a symmetry condition was applied at the bottom; and a combined radiation-convection boundary condition governed heat loss along the top surface. Since the thermal conductivity and specific heat of the candidate materials vary with temperature, the problem was treated as nonlinear, with convergence enforced at every time step. Three materials were evaluated: Inconel 718 (INC-718), Niobium C-103, and AISI-304 Steel under both linear and nonlinear thermal property assumptions, and with varying insulation thicknesses.
Key Outcomes [Click here ....]:
Both numerical methods produced consistent temperature distributions, validating the formulations against each other. The nonlinear simulations revealed noticeably different temperature fields compared to the linear assumption, underscoring the importance of accounting for temperature-dependent material properties in high-flux environments.
Among the materials tested, C-103 and INC-718 significantly outperformed AISI-304 Steel. Steel reached a peak temperature of 2465 K without insulation, far beyond what the structure could safely withstand, whereas INC-718 and C-103 remained considerably lower at 1554 K and 1325 K, respectively. Insulation proved highly effective across all materials, reducing peak temperatures by 18% to 37%, depending on the material. For INC-718 specifically, increasing the insulation thickness from 1 mm to 3 mm reduced the maximum temperature from 1300 K to 981 K. A grid independence study confirmed that a 61×61-node resolution produced well-converged results, with the normalized L2 norm and the maximum absolute temperature difference used as convergence metrics.