Hypersonic Vst Mac Link

(conceptual plot): L/D vs. Mach number — VST-MAC outperforms fixed-delta and fixed-sweep designs by 15-40%. 4.3 Thermal-Structural Feasibility The leading edges are C/C-SiC composites with active cooling (endothermic fuel). Fuselage morphing segments use NiTi SMA wires embedded in a high-temperature polymer matrix, rated to 850 K transient. At Mach 6.5 stagnation temperatures reach 2200 K on nose, but the morphing mechanism is located 1.5 m aft of the stagnation line, staying below 700 K. 5. Control and Stability Variable sweep and tilt alter the aerodynamic center (AC). At low speed (Λ=20°, anhedral), AC is at 45% MAC. At hypersonic (Λ=75°, dihedral), AC shifts to 38% MAC. The flight computer uses a gain-scheduled LQR controller, adjusting elevator, canards (deployed only subsonically), and differential wing tilt for roll control.

Lift coefficient in hypersonic regime (Newtonian theory): hypersonic vst mac

[ C_L = 2\sin^2\theta_p \cdot \cos\Lambda ] (conceptual plot): L/D vs

Hypersonic VST-MAC: A Variable-Sweep/Tilt Mach-Area Ruled Configuration for Multi-Regime Flight Fuselage morphing segments use NiTi SMA wires embedded

| Mach | Fixed fuselage (C_D_w) | MAC fuselage (C_D_w) | % reduction | |------|---------------------------|--------------------------|--------------| | 0.9 | 0.009 | 0.008 | 11% | | 1.2 | 0.045 | 0.027 | 40% | | 2.5 | 0.031 | 0.021 | 32% | | 6.0 | 0.022 | 0.018 | 18% | 4.2 Aerodynamic Efficiency (L/D) The VST wing improves L/D across all regimes. At Mach 0.8, low sweep (20°) and slight anhedral (-5°) give L/D = 14. At Mach 5.0, sweep 75°, dihedral +20° yields L/D = 5.2 — high for a hypersonic vehicle (typical L/D ~ 3-4). The improvement stems from reduced induced drag via spanwise load redistribution at hypersonic speeds.

[ A(x) = A_\textmax \cdot \frac4xL\left(1 - \fracxL\right)^3/2 ]

However, optimal (A(x)) shifts with (M). The MAC fuselage consists of overlapping, segmented panels reinforced with shape memory alloy (SMA) ribs that contract or expand, altering the radius at each station (x). For hypersonic flight, the nose becomes sharper (lower bluntness ratio) and the midbody swells to reduce wave drag. The wing uses a dual-pivot mechanism embedded in a thermally insulated wing box. Sweep angle (\Lambda) changes via linear actuators, while tilt (\theta_t) changes via rotary joints at the root.