Objectives and content:
The fuselage is one of the major sources of drag for the helicopter in forward flight conditions, representing about 50% of the total power consumed at high-speed. Helicopter fuselage drag evaluation and reduction are therefore of primary interest to industry in order to increase the helicopter market, by increasing helicopter speed and range capability, and reducing operational cost.
To reduce significantly helicopter fuselage drag, two main topics have to be addressed:- to develop reliable prediction tools in order to get the capability to optimise the fuselage shape and reduce the drag at an early stage of the design process;- to have reliable wind-tunnel test techniques in order to obtain an accurate estimate of the fuselage drag before the first prototype flights.
The research activity covered by this programme deals with both aspects of the problem, giving:- a well-documented database on a Dauphin fuselage wind-tunnel model, giving in particular the influence of Reynolds number on the forces and moments acting on the fuselage; this model is also particularly well-adapted for codes validation, with its modular shape giving access to experimental data on various fuselage shapes, from the basic Dauphin fuselage to the realistic one, including the rotor hub and fairings; the experiment will give the pressure distribution on the fuselage (with up to 200 pressure taps), global forces and moments from a 6-components balance, streamlines, transition line and separation line on the fuselage surface;- a common exercise with existing Navier-Stokes methods, including thre successive subtasks; in the first subtask, the wind-tunnel model configurations will be computed before conduction of the tests by the various partners, in order to have a reliable statement about Navier-Stokes methods prediction capability with particular emphasis on the industry needs (e.g. drag estimate); then, the various Navier-Stokes codes will be improved in terms of efficiency and accuracy, working more particularly on two aspects(turbulence modelling and numerical algorithm at low-speed), and using the lessons learned from the prediction exercise; during the last subtask, the improved methods will be validated versus previous calculations, experiment and computations performed by other partners; whenever possible, identical grids will be used by different partners in order to highlight the differences between the algorithms used in each Navier-Stokes method; again, attention will be given to the industrial applicability of such methods. The partners working in this research programme are three national research institutes (ONERA, DLR and CIRA), three helicopter manufacturers (AGUSTA, ECF and WHL), a software company (SIMULOG) and three universities (DTU, IAG, Uni. Roma 3).
Funding SchemeCSC - Cost-sharing contracts
21017 Cascina Costa Di Samarate Varese
06560 Sophia Antipolis