INDUSTRIAL USE OF COMPUTATIONAL FLUID DYNAMICS IN THE HELICOPTER DESIGN PROCESS

The paper describes the use of CFD (Computational Fluid Dynamics) in the industrial design process. A prerequisite for this goal is a direct interface between the CAD design tool and the CFD grid generator software. Two examples, describing the design process as it is used at EUROCOPTER, are presented here. An internal aerodynamic optimisation case: the EC135 air intake, and an external aerodynamic case: the comparison between two rotor hubs. The air intake optimisation study showed the ability of CFD to highlight problems and to identify modifications aiming at improving the flow qualities in the domain of interest. In fact, the updates made to the original air intake configuration showed a decrease of the total pressure losses in some regions of the domain up to 80%. Although the rotor hub comparison section does not yet present the optimisation process for the new model, it shows the starting configuration of a future design and introduces the criteria which shall be accounted for to improve the aerodynamic characteristics of a new rotor hub geometry.