Multistage Turbomachinery Design Using the Discrete Adjoint Method Within the Open-Source Software SU2

摘要

This paper documents a fully turbulent discrete adjoint method for three-dimensional multistage turbomachinerydesign. The method is based on a duality preserving algorithm and is implemented in the open-source computationalfluid dynamics tool SU2. The SU2 Reynolds-averaged Navier–Stokes solver is first extended to treat threedimensionalsteady turbomachinery flow using a conservative formulation of the mixing-plane coupled tononreflective boundary conditions. The numerical features of the flow solver are automatically inherited by thediscrete adjoint solver, ensuring the same convergence rate of the primal solver. The flow solver is then validatedagainst experimental data available for three turbine configurations, namely, a one-and-half axial turbine stage, atransonic radial turbine coupled to a downstream diffuser, and a supersonic mini–organic Rankine cycle radialturbine operating with a fluid made by a heavy molecule. Finally the adjoint-based optimization framework is appliedto the concurrent shape optimization of three rows of the axial turbine, demonstrating the advantages deriving fromadopting multirow automated design methods in the context of turbomachinery design.