Multiphysics Topology Optimization with Application to Molten Salt Fast Reactor

In the last decades, topology optimisation is playing an increasingly important role in the industrial design approach for different applications, including structural mechanics, civil engineering, architecture and fluid mechanics. This work aims at improving the studies regarding multiphysics topology optimisation of systems governed by fluid flow and heat transfer, including an application to the Molten Salt Fast Reactor (MSFR), investigating two different approaches. At first, this work assesses the well-established gradient-based algorithms using 2D benchmarks using COMSOLMulti-physics. These results represent the starting point for developing an adjoint-based open-source optimisation solver in OpenFOAM for non-adiabatic flows. This method, defined by a Lagrangian formalism of the sensitivity analysis, led to promising results, with lower computational cost but higher residuals, which underlined the need for further tests. Finally, this work considers the topology optimisation of the EVOL geometry of the MSFR,aimedatminimising the temperature gradient and pressure drops inside the reactor. The results showed impressive improvements regarding the system operative conditions.