A Study of the Method of Surface Fit Approximations for Aircraft Optimal Design.

摘要

A study was made to demonstrate the feasibility of using surface fit approximations in the design analysis of an advanced tactical fighter. Design variables were selected and a design space was defined based on a simple latin square method. The take-off-gross-weight (TOGW) and landing distance (DISTL) for each configuration were determined by use of a computer program which simulated the required mission. A regression analysis was performed on this data to obtain a quadratic surface fit representing TOGW and DISTL as functions of the design variables. A conjugate gradient technique was employed to find the minimum TOGW subject to constraints on DISTL within the design space. This value was compared to the minimum obtained by running all possible combinations of design variables through the mission simulator. It was concluded that the surface fit approximation based on the latin square design space did yield accurate results and required fewer computer simulations. (Author)