Determination of Cycle Configuration of Gas Turbines and Aircraft Engines by Optimization Procedure

Abstract

This paper is devoted to the analyses and optimization of simple and sophisticated cycles, particularly for various gas turbine engines and aero-engines (including scramjet engine) to achive the maximum performance. The optimization of such criteria as thermal efficiency, specific output and total performance for gas turbine engines, and overall efficiency, non-dimensional thrust and specific impulse for aero-engines have been performed by the optimization procedure with multiplier method. The comparisons of results with analytical solutions establishes the validity of the optimization procedure.

Periodic Optimal Cruise for a Hypersonic Vehicle with Constraints

“…The rst-order necessary conditions are obtained by substituting N H for H in Eqs. (19)(20)(21) and (23). Other necessary conditions are added for this state inequality problem to ensure that the trajectory meets the speci ed maximum heating rate at the entry points to the boundary:…”

“…According to the procedure just stated, point B is reached (step 2), which belongs to a family of periodic extremal paths satisfying Eqs. (19)(20)(21)(22). The curve drawn in Fig.…”

“…The rst-order necessary conditions are obtained simply by replacing H in Eqs. (19)(20)(21) and (23) a nite difference approximation to the Jacobian is used to solve it numerically. When the standard atmospheric model is used for a problem in which the solution includes a constrained subarc, the sensitivity to initial guesses of the subroutine that solves for ®, s, and ¹ leads to more dif culty than for a problem whose solution is a touch-pointtype such as the problem in the next section.…”