NEWPAN-NASTRAN Aeroelastics

It is important in the structural design of aerospace and automotive vehicles to provide accurate estimates for the loads. Usually aerodynamic loads are significant, and furthermore depend themselves upon the aerodynamically induced structural deformation. The relationship between the change in deformation and the change in loading is usually non-linear, hence getting reliable static aerodynamic loads for such cases has often proved difficult.

Non-linear analysis of the aero-structural coupled problem provides a solution. An analysis is needed that feeds the structural deformation back into the aerodynamic solver and the aerodynamic forces back to the FEM analysis; this results in an iterative solution procedure. This analysis provides the deformed aerodynamic mesh for the aerodynamic department and the aerodynamic forces on the deformed structure for the design and structural departments.

Flow Solutions in partnership with MSC Software are able to provide a coupled NEWPAN-NASTRAN solution to the static aeroelastics problem. The procedure may be summarised as follows:

• Import the NEWPAN model into a MSC.Patran database containing the structural model;
• Create the splines between the aerodynamic and structural mesh using MSC.Flightloads;
• Verify the splines with the results of a structural modal analysis;
• Export the aerodynamic model as a MSC.Nastran Aerodynamic Database;
• Export the aeroelastic model containing the splines as a MSC.Nastran Aeroelastics Database;
• Define the parameters of the integrated analysis run;
• Run the NEWPAN-NASTRAN iterative analysis;
• Post-process the results using MSC and Flow Solutions post-processors.

An example of the aeroelastic analysis of a two element Formula One racecar front wing assembly using NEWPAN-NASTRAN is presented here. Thanks to the speed of execution of NEWPAN and the rapid convergence of the iterative procedure, coupled solutions may be obtained in a matter of minutes.