Aerodynamic Investigations of system devices on the ATR-72-500 Maritime Patrol Aircraft (MPA), Final Report

Abstract

The Aerodata AG, Braunschweig, assigned the DLR Institute of Aerodynamics and Flow Technology to investigate the aerodynamic characteristics of system devices mounted at the ATR-72-500 aircraft. The aim of the investigations is to determine the aerodynamic loads on several system devices mounted on the aircraft as well as an estimation of the flight trajectories of different store releases. As a result the loads affecting the mounted devices and a comparison between the drag of the aircraft with and without mounted system devices will be carried out as well as the assessment of a collision free release of different stores. The geometries of the aircraft, system devices and stores have been provided by Aerodata. The aircraft CAD geometry is based on a 3D scanned and digitized model of an existing ATR72-500 Maritime Patrol Aircraft (MPA) in ground shape. DLR combined the geometries of the aircraft and components based on specifications provided by Aerodata. Steady and unsteady aerodynamic loads were determined by solving the Reynoldsaveraged Navier-Stokes (RANS) equations with the DLR flow solver TAU, applying a Spalart Allmaras turbulence model. For the store release simulations an overlapping, so-called chimera grid approach has been carried out. The time accurate store release itself, to simulate the relative motion between aircraft and store, has been realized with an unsteady dual time stepping approach coupled with the flightmechanicsmodule in TAU. The flight cases were provided by Aerodata and represent different flight cases in cruise altitude as well as flight envelope limit conditions.