VAST - Flexible Aeromechanics Simulation Platform for Helicopters

Abstract

In the DLR-Project VicToria (Virtual Aircraft Technology Integration Platform, 7/2016 – 12/2019) the basis of VAST is being developed. Halfway through the project a prototype version exists that clearly demonstrates the potential of the approach pursued here. This paper describes the concept and goals of the code and shows results of the current development version (see Fig. 1). The principal idea is a coupled system of models that are expressed as state-space models (See Fig. 1) ẋ = F(u,x,t) with the implicit system of coupling equations y = G(u,x,t) being automatically resolved. This approach allows generic methods for solving the system to be developed unlike many other codes in the field which require highly specialized solution procedures and are thus rigid to change. The logic for the model interconnection is kept completely outside of the simulation code and computed as a prestep. The basis of physical models is taken from existing research codes like S4 and the FT-Freewake [2] as well as implementation of proven numerical models like a dynamic wake model [3] and its recent extensions. The structural dynamics is calculated using an internal structural model using rigid multi body dynamics as well as an adaptive coupling to SIMPACK building on [4]. First applications to the free flying helicopter and the wind tunnel case are shown and discussed