Development of a robust solver to model the flow inside the engines for high-speed propulsion

Von Karman Institute for Fluid Dynamics, Rhode Saint-Genèse, 1640 Brussels, Belgium

^* Corresponding author: ludovico.nista@vki.ac.be

Abstract

The demand for discovering new commercial routes as well as the possibility to shortening civilian long-haul flights boosted the interest of civil hypersonic vehicle designs. Among all the multiple projects started by the various nations, the European community funded project STRATOFLY aims at refining the baseline LAPCAT II-MR2.4 design for further improvements. The new aircraft would enable a flight shorter that 3 hours from Brussels to Sydney, carrying 300-passengers above the already crowed atmosphere. The wide Mach range operability, up to Mach 8, demands the use of multiple engines, leading to a highly integrated propulsion system. The current study is focused on the development of new CFD platform to estimate the performance of the combined propulsion system during the supersonic to hypersonic transition. In order to control the complex flow physics, highfidelity CFD simulations remain the fundamental tools for the preliminary investigations. On the current framework, an advanced robust compressible solver has been develop d in order to handle the different flow regimes. The new tool solves Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations by employing cell-centered Finite Volume Method constructed on openFoam toolbox. Two innovative high-order discretization schemes, with different abilities, based on approximated Riemann solvers were developed for capturing the flow physics within high-speed propulsion systems. Advanced time discretization has been taken into account to increase the temporal accuracy. At the end, the whole implementation has been validated in multiple test cases, ranging from incompressible to hypersonic regimes, confirming its excellent stability, robustness and accuracy.