Coupling between an Actuator Disk and a Navier-Stokes-Solver: Application to a Missile with Latice Wings

Abstract

This study focuses on the numerical simulation of supersonic and hypersonic flows around a missile with lattice wings. In order to reduce the computational cost by one order of magnitude for such a configuration, the actuator disk concept has been chosen to model the effects of grid fins. This method, already incorporated in DLR's FLOWER code, consists in replacing the lattice controls by artificial boundary conditions where the forces involved by the grid fins are applied. These forces are interpolated from an experimental database. A previous study showed that this approach is able to predict the flow around an isolated lattice wing. Here, this method is applied to the simulation of the flow around a missile with grid fins. This allows the prediction of the forces applied to the vehicle and therefore an estimate of its aerodynamic performances. Different numerical simulations have been performed at Mach 1.8 and 4 for laminar and turbulent flows with and without angle of attack. The drag predictions are compared to the experimental data obtained in DLR Köln for the same configuration. The comparisons put in evidence some discrepancies. A test using the data obtained in DLR Köln for an isolated lattice wing showed that these differences were mainly due to the database from which the forces involved by the lattice wings are interpolated. This study has validated the approach and shown its potential to be used as a tool for vehicle design.