Numerical Investigation of Jet Effects on the Dornier 328 EC Wind Tunnel Model

Kurzfassung

A model of the Dornier 328 JET transport aircraft with two mounted Turbine Powered Simulators (TPS) has been tested in the Low Speed wind tunnel (DNW-NWB) at the DLR in Braunschweig (Germany). During the tests it was observed that with increasing thrust the lift coefficient decreased. It was assumed that the increasing engine jet velocity decreases the pressure below the wing in the vicinity of the pylon and therefore the lift of the whole airplane would be reduced. In order to examine this strong influence of the engine jet as cause for the reduction of lift, numerical flow-simulations with an Euler-solver for unstructured tetrahedral grids were performed. The result of these numerical investigations is, that this effect could not be confirmed, the lift stayed nearly constant. Additionally the iso-Mach number distributions on the pylon and the rear of the nacelle for different power settings do not vary significantly.