捆绑火箭气动载荷分布不确定性分析

Aimed at the uncertainty of the aerodynamic load distribution of strap-on launch vehicles due to the uncertainty of flight status and shape parameters, a method based on the polynomial chaos theory to analyze the aerodynamic load distribution characteristics and quantify the uncertainty of the strap-on launch vehicle is proposed. A two-strap-on configuration was used as an example to verify the method. First, a method for uncertainty analysis of aerodynamic loads of the strap-on launch vehicles was proposed, and the simulation analysis process was given. Second, the method was verified by a two-strap-on configuration, the aerodynamic shape parametric model was established, and the aerodynamic characteristic analysis result was verified. Finally, the sensitivity analysis of influencing factors and the uncertainty analysis of load distribution were carried out, the influencing degree of different factors and the uncertainty distribution form of aerodynamic axial force and normal force were obtained according to the proposed method, and the flow mechanism was analyzed. The analysis results provide reference for the aerodynamic load control of strap-on launch vehicle. By describing the aerodynamic load uncertainty quantitatively, the safety factor redundancy can be reduced effectively and the basis of accurate structural design can be provided.