Differentiable Surface Mesh Deformation for Non-Conformal, Independently Parameterized Components with Large Shape Changes

System-level aircraft conceptual design can be viewed as a high-dimensional, multidisciplinary design optimization (MDO) problem involving potentially thousands of design variables across multiple subsystems and design conditions. Recent advances in modeling and adjoint-based sensitivity analysis have enabled the use of low-fidelity physics-based models to solve this complex problem in a computationally efficient manner using established MDO algorithms. However, integrating higher-fidelity aerodynamic simulations into comprehensive, large-scale MDO of aircraft concepts remains challenging. This is in large part due to the increased computational cost and the large geometric changes that may occur at the conceptual design stage. Since many mid- to high-fidelity aerodynamic solvers require conforming surface meshes, there is a need for a general deformation method that efficiently updates surface mesh nodes based on changes to the design geometry in a differentiable manner. In this paper, we aim to fill this need by developing such a method using a two-step process: 1) recompute intersections between components given large geometric changes and 2) deform the surface mesh using thin plate splines to conform to the updated intersections. The method is reasonably efficient and all steps are differentiable. We test our method on a simple tube-and-wing geometry for which we translate and rotate the wing with respect to the fuselage. The method performs well for all considered rotation angles (±10 degrees) with over 95% of triangles being of acceptable quality. For translations, the performance is similar up to 1.5 times the chord length. We couple the method with a panel-method aerodynamic solver, confirming its applicability in aircraft conceptual design.