Development of Aircraft Flight Loads Analysis Models with Uncertainties for Pre-Design Studies

Kurzfassung

This paper addresses the development of analysis tools for flight loads prediction in the pre-design stage. The analysis tools are embedded in a parametric modelling environment. Emphasis will be on prediction of aerodynamic loads on specific structural parts, like the fin, during dynamic manoeuvres. Principal requirement is that these loads can be computed with low effort, but with sufficient accuracy. In the frame of this work, an availale transport aircraft model has been taken as reference. The aerodynamic loads on the fin are computed using the Vortex Lattice Method (VLM), allowing for comparison with the original aerodynamics data base. For this structural component of the aircraft, a dense panel grid is chosen. In order to account for aerodynamic cross interferences, the remainder of the aircraft geometry is also taken into account, but with a considerably coarser grid. From the comparison with the original database, correction factors and uncertainty bounds are estimated. Next, the geometry of the fin is modified. Based on aerodynamic loads computed with the VLM, the impact on (lateral) manoeuvre loads is analyzed. Hereby the estimated uncertainty levels from the first step are used to predict sensiivities for consideration instructuralsizing.