Multidisciplinary topology optimization for reduction of sloshing in aircraft fuel tanks based on SPH simulation

In this article, we focus on a design problem of fuel tank structures within the framework of explicit topology optimization. A multi-physics computational model is presented to evaluate the 3-dimensional fuel-structural system in an aircraft wing tank, which comprises two coupled solvers: a finite element solver for the deformed rib structures and a smoothed particle hydrodynamics (SPH) solver for the sloshing fuel. The optimizer is established using the moving morphable components (MMC) based framework, where the topologically complicated fuel transmitting holes are described explicitly by parameterized level-set surfaces, which is quite different from the implicit description way of the SIMP method (i.e., elementwise 0-and-1 density distribution), providing a great advantage in dealing with boundary-dependent loads, which is usually encountered in fuel-structural systems. The design optimization is accomplished using an iterative method with subcycling of the SPH solver to resolve the transient flow field resulting from the fuel slosh in a 3-dimensional tank model. The effectiveness of the proposed method is verified through a real tank structure by comparing the fuel-immeasurability of the original structure and the optimized one.