Numerical Study on the Effect of Non-Equilibrium Condensation on Drag Divergence Mach Number in a Transonic Moist Air Flow

In the present study, the effects of non-equilibrium condensation on the drag divergence Mach number with the angle of attack in a transonic 2D moist air flow of NACA0012 are investigated using the TVD finite difference scheme. For the same α, the maximum upstream Mach number of the shock wave, Mmax, and the size of supersonic bubble decrease with the increase in Φ₀. For the same M_∞, Φ₀, and T₀, the length of the non-equilibrium condensation zone Δ_z decreases with increasing Φ₀. On the other hand, because of the attenuating effect of non-equilibrium condensation on wave drag, which is related to the interaction between the shock wave and the boundary layer, the drag coefficient C_D decreases with an increase in Φ₀ for the same M_∞ and α. For the same α, M_D increases with increasing Φ₀, while M_D decreases with an increase in α.