On the Coupling of a Zonal Body-Fitted/Immersed Boundary Method with ZDES: Application to the Interactions on a Realistic Space Launcher Afterbody Flow

Abstract

One of the next foreseen challenges in CFD consists in the capability to simulate quantitatively the spectral content of the turbulent flow around realistic geometries. In this context, the present work focuses on a new methodology named ZIBC standing for Zonal Immersed Boundary Conditions (Mochel et al. in AIAA J 52(12):2782–2794, 2014, [14]) enabling to account for complex configurations (Hannemann et al. in Launch vehicle base buffeting: recent experimental and numerical investigations. ESTEC, Noordwijk, 2011, [13], Schwane in J Spacecr Rocket 52:54–62, 2014, [21], Pain in AIAA J 52:1967–1979, 2014, [17], Weiss and Deck in ZDES of the flow dynamics on an Ariane 5-type afterbody with and without struts, 2015, [26]) at high Reynolds number. The numerical strategy allowing the coupling between a modelling method (e.g. RANS, URANS, ZDES, LES or DNS) and IBC (Immersed Boundary Conditions) is detailed. In this paper, the modelling method retained is the Zonal Detached Eddy Simulation (ZDES) which has reached a high level of maturity on turbulent separated flows (Deck and Thorigny in Phys Fluids 19(065103), 2007, [8], Weiss et al. in Phys Fluids 21(075103), 2009, [27], Weiss and Deck in Phys Fluids 23(095102), 2011, [24], Weiss and Deck in Flow Turbul Combust 91:687–715, 2013, [25]). Then, the methodology is applied to a full space launcher configuration to assess its capability to return the interactions between the technological details, modelled with IBC, and the simplified afterbody, modelled with a body-fitted (BF) approach consisting in classical no-slip boundary conditions, in the turbulent flow field surrounding the main stage of the space launcher afterbody. The proposed method is thoroughly assessed on a realistic geometry of the European Ariane 5 launcher and the ZIBC simulation is successfully compared with the available experiments.