Aerodynamic Loads Prediction in an Integrated Computer-Based Conceptual Design Environment

An important aspect of successful aircraft design is the concept of ‘right first time’, as any design changes downstream can be costly and may cause project delays. This is most applicable to the conceptual design phase. However, in the early stages of aircraft design, data is limited and prone to inaccuracies. Consequently, a design will typically traverse through a number of iterations, improving and refining with each step. Over the past 15 years, computer-based tools have become commonplace in aircraft design [1]. In general, most computer-based tools have been developed for the more advanced stages of the design process. For these tools to be useful in conceptual design, they must be user-friendly, interactive, and provide quick return times. A classic example is the aerodynamic load data required for structural design. Both are dependent on geometric parameters, which may still be subject to change. To complete the analysis within practical time constraints, a highly integrated and automated system is required [2, 3]. This paper presents such a system, developed using industry accepted software components including AutoCAD, VSAERO and MSC Nastran. This system allows an automatic, structured topology mesh to be generated from a basic three-view aircraft drawing, which inputs directly into VSAERO for loads calculations. The loads are subsequently transferred to MSC Patran as a pre-processor for structural analysis using MSC Nastran. If the result is unsatisfactory, the geometry or placement of structural components can easily be changed and the process repeated. The design environment was developed using FORTRAN90. The results of an application of this system to a simple wing, as well as a regional transport aircraft, are also presented.