Preliminary Design of a Novel Multi-Stage Nose Cone for Hypersonic Aircraft Forebody

This study systematically investigates the design principles of variable nose cones for hypersonic vehicles and their impact on aerodynamic performance. A multi-stage variable nose cone design method, based on a one-stage variable nose cone, is proposed, preserving the dimensional parameters of each stage nose cone. The aerodynamic characteristics of one-stage to five-stage variable nose cones at a 15° yaw angle and 0° to 10° angle of attack are analyzed using the GoCart software. Through analysis of lift, drag, lift-to-drag ratio, and pitch moment coefficients and their variations: It is revealed that the nose cone outperforms the rudder by 4.53% in lift-to-drag ratio and by 12.8% in pitch moment. The nose cone's advantage in pitch control efficiency enhances stability and high maneuverability; As the number of nose cone stages increases, the lift-to-drag ratio rises while the drag diminishes. Furthermore, with the same yaw angle, larger stage numbers result in less deformation. The five-stage variable nose cone enhances lift-to-drag ratio by 33.3% and reduces drag by 20.8% compared to the one-stage variant. The relative change in projected area of the one-stage variable nose cone compared to the five-stage variant is only 0.1%; The lift-to-drag ratio difference between the five-stage and three-stage variable nose cones is merely 3.06%. Taking into account the attenuation of lift-to-drag ratio, increase in moment coefficients, and engineering feasibility, the three-stage variable nose cone is identified as the optimal design solution.