An idea of distributed parameter control for scramjet engines

Abstract

Scramjet engines are used under extreme temperatures and with wide range of Mach numbers from 3 to 8 or higher and have shown different control properties from other airbreathing engines. New control problems involving distributed parameter control have been found concerning investigations of the control of scramjet engines whose physical states are spatially interacted and whose governing equations are partial differential equations. The work of this paper is based on the application of distributed parameter control conception to study the control problems of scramjet engines with the aim of achieving the desirable design properties and increasing control reliability. A new control idea based on shape control theory is put forward to realise the distributed parameter control of scramjet engines with the preconditions of proper space dimension and frequency-domain simplification. Simulation results and theoretic analysis for an axisymmetric, wall-injection scramjet engine show the feasibility and validity of the control idea.

Distributed parameter control arithmetic for an axisymmetrical dual-mode scramjet

“…Presently we consider the shape control of dual-mode scramjet as a one-dimensional steady control problem (6) aiming at control Mach number distribution (or pressure distribution). Control variables of the control system are the fuel flow rates in different fuel injections, which can be substituted by the equivalent variables: stagnation temperature rise ratio τ = [τ 1 , τ 2 , ⋅⋅⋅, τ m ] where the subscript m denotes the number of fuel injections.…”

“…In the first part of this paper, the fundamental control problems of dual-mode scramjet will be again illuminated as presented in Ref. 6 to help understanding the whole distributed parameter control problem of dual-mode scramjet. In the second part, the shape control method is presented to solve the distributed parameter control problem.…”

Simplified procedure for controlling pressure distribution of a scramjet combustor

“…11 So there are benefits from thinking scramjet engines in terms of continuum mechanics with distributed parameter control. To help solve the problems existing in the combustion control of scramjet engines, Daren et al 12 and Tao et al 13 made some suggestions from a viewpoint of applying distributed parameter control technologies to the control of scramjet engines, and the studies have provided an initial proof of the validity of distributed parameter control for scramjet engines. However, from a viewpoint of engineering application, the proposed distributed parameter control arithmetic is in need of computation of the sensitivity function to provide the gradients of the objective function, and is computationally expensive and complex.…”