# An Effective Simulation Scheme for Predicting the Aerodynamic Heat of a Scramjet-Propelled Vehicle
## 3 Validation Tests
### High Supersonic Stage
#### 3.3.3 Simulation Parameters
Figure 16b sums up the wall pressure coefficient distributions from the experiment and the simulation at \(T_{W}\) = 290 K adopting the Spalart-Allmaras model. The overall distribution trend of the simulation data matched well with the experiment data and the simulation results were very close to the experiment data at the upper stream of the wedge section. Figure 17a shows the error ratio distribution of the wall pressure coefficient at the wedge section. The results based on a cell Reynolds number of 16 and an AUSM+ flux type were the closest to the experimental data and the average error ratio was about 11.18%. The aspect ratios 400, 200, 100, and 50 were adopted; Figure 17b reveals the distribution diagram of the error ratio of the pressure coefficient. As the aspect ratio decreased, the error ratio decreased. When the aspect ratio was equal to 200, the optimal simulation results could be obtained, and the mean error, error variance. and mean error ratio were 0.027, 8.95 \(\times\) 10\({}^{-5}\), and 10.9%, respectively. Subsequently, as the aspect ratio decreased, the error ratio increased. Primarily, at \(T_{W}\) = 290 K, the optimal results were achieved based on a grid strategy applying a cell Reynolds number of 16 and an aspect ratio of 200, and a numerical method accepting the SST k-omega model, the density-based solver, and the AUSM+ flux type. Figure 12: (a) wall pressure coefficient distribution diagram adopting SST K-omega at \(T_{W}\) = 100 K; (b) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting SST K-omega at \(T_{W}\) = 100 K.  
Figure 13: (a) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting four different aspect ratios; (b) wall pressure coefficient distribution diagram adopting Spalart-Allmaras at \(T_{W}\) = 100 K.  
Figure 16: (**a**) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting four different aspect ratios; (**b**) wall pressure coefficient distribution diagram adopting Spalart-Allmaras at \(T_{W}\) = 290 K.  
Figure 14: (**a**) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting Spalart-Allmaras at \(T_{W}\) = 100 K; (**b**) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting four different aspect ratios. Figure 15: (**a**) wall pressure coefficient distribution diagram adopting SST K-omega at \(T_{W}\) = 290 K; (**b**) error ratio of wall pressure coefficient distribution diagram at the wedge section adopting SST K-omega at \(T_{W}\) = 290 K.  
In conclusion, the performance of the SST k-omega model was better than that of the Spalart-Allmaras model for the wedge section at the high supersonic stage. When \(T_{W}/T_{r}\) is less than 0.3, the mesh with \(y^{+}\) is 0.3, the cell Reynolds number is 40 and the aspect ratio is 100, the turbulence model applying Spalart-Allmaras and the density-based solver applying the AUSM+ flux type is preferred. When \(T_{W}/T_{r}\) is greater than 0.3, the mesh with \(y^{+}\) is 0.3, the cell Reynolds number is 16, and the aspect ratio is 200, the turbulence model applying SST k-omega and the density-based solver applying the AUSM+ flux type is preferred.