NUMERICAL OPTIMIZATION OF SINGLE-STAGE-TO-ORBIT CONFIGURATION WITH INEQUALITY CONSTRAINTS

THE OBJECTIVE OF THIS PROPOSAL IS TO PERFORM NUMERICAL OPTIMIZATION OF HYPERSONIC BODY CONFIGURATIONS APPLICABLE TOSINGLE-STAGE-TO-ORBIT AEROSPACE PLANE CONFIGURATIONS. FORMAL OPTIMIZATION OF HIGH-SPEED VEHICLE CONFIGURATIONS IN TERMS OF MINIMIZING SOME COST FUNCTION HAS BEEN LIMITED TO SIMPLE AXISYMMETRIC SHAPES ADDRESSED USING SIMPLIFIED AERODYNAMIC THEORIES. RECENT DEVELOPMENTS ALLOW COMPLEX OPTIMIZATION PROBLEMS TO BE SOLVED NUMERICALLY, WHEREIN THE OPTIMIZATION PROCESS IS CONVERTED INTO A PROBLEM IN NONLINEAR PROGRAMMING. SPECIFICALLY, RESEARCHERS AT INTEGRATED SYSTEMS, INC., HAVE DEVELOPED A NEW INTERIOR QUADRATIC PROGRAMMING (QP) PROCEDURE FOR SOLVING SUBOPTIMIZATION PROBLEMS WITH FASTER CONVERGENCE THAN WAS PREVIOUSLY POSSIBLE. THE NEW QP ALGORITHM IS EMBEDDED WITHIN AN AUGMENTED LAGRANGIAN (AL) APPROACH FOR SOLVING GENERAL NONLINEAR PROGRAMMING PROBLEMS. ISI PROPOSES TO DEVELOP A GENERAL CONTROL-ORIENTED METHOD FOR SPECIFYING BODY OPTIMIZATION ALGORITHM. THE BODY GEOMETRY SUBROUTINE WILL PROVIDE DEFINITION OF THE EXTERNAL SHAPES OF HYPERSONICVEHICLES FOR A COMPUTATIONAL FLUID DYNAMICS CODE THAT WILL BE USED TO EVALUATE THE PERFORMANCE INDEX. PERFORMANCE INDICES (COST FUNCTIONS) WILL BE CONSTRUCTED THAT REFLECT THE PRINCIPAL MEASURES OF MERIT, AND INEQUALITY CONSTRAINTS WILL BE APPLIED TO REPRESENT HEATING RATE AND COMPONENT PACKAGING CONSTRAINTS AT VARIOUS LEVELS. OPTIMIZATION RUNS WILL BE ACCOMPLISHED TO DEFINE THE OPTIMUM BODY SHAPES FOR VARIOUS FLIGHT CONDITIONS.