Adjoint-based shape optimization for the minimization of flow-induced hemolysis in biomedical applications

Abstract

This paper reports on the derivation and implementation of a shape optimization procedure for the minimization of hemolysis induction in blood flows through biomedical devices.Despite the significant progress in relevant experimental studies, the ever-growing advances in computational science have made computational fluid dynamics an indispensable tool for the design of biomedical devices. However, even the latter can lead to a restrictive cost when the model requires an extensive number of computational elements or when the simulation needs to be overly repeated. This work aims at the formulation of a continuous adjoint complement to a power-law hemolysis prediction model dedicated to efficiently identifying the shape sensitivity to hemolysis. The proposed approach can accompany any gradient-based optimization method at the cost of approximately one additional flow solution per shape update. The approach is verified against analytical solutions of a benchmark problem and computed sensitivity derivatives are validated by a finite differences study on a generic 2D stenosed geometry. The included application addresses a 3D ducted geometry which features typical characteristics of blood-carrying devices. An optimized shape, leading to a potential improvement up to 22%, is identified. It is shown that the improvement persists for different hemolysis-evaluation parameters.