APPLICATION OF HYBRID AERO-ENGINE MODEL FOR INTEGRATED FLIGHT/PROPULSION OPTIMAL CONTROL

The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming （SQP）. Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.

THE EIGENVALUE SENSITIVITY ANALYSIS AND DESIGN FOR INTEGRATED FLIGHT/PROPULSION CONTROL SYSTEM

In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling performances of the aircraft. The eigenvalue sen sitivity approach is employed to study the effect of coupling parameters on system stability and gain sensitivity approach is used to direct the reduced states feedback suboptimal control system design. Simulation results show that the integrated flight propulsion control system designed by sensitivity approaches is of good performance.

Novel Ship Propulsion System

As the development tends towards high-speed, large-scale and high-power, power of the ship main engine becomes larger and larger. This make the engine design and cabin arrangement become more and more difficult. Ship maneuverability becomes bad. A new ship propulsion system, integrated hydraulic propulsion （IHP）, is put forward to meet the development of modem ship. Principle of IHP system is discussed. Working condition matching characteristic of IHP ship is studied based on its matching characteristic charts. According to their propulsion principle, dynamic mathematic models of IHP ship and direct propulsion （DP） ship are developed. These two models are verified by test sailing and test stand data. Based on the software Matlab/Simulink, comparison research between IHP ship and DP ship is conducted. The results show that cabin arrangement of IHP ship is very flexible, working condition matching characteristic of IHP ship is good, the ratio of power to weight of IHP ship is larger than DP ship, and maneuverability is excellent. IHP system is suitable for engineering ship, superpower ship and warship, etc.

Theoretical fundamentals of airframe/ propulsion integration for high-speed aircraft

Fundamental features of aerodynamic interference and integration of airframes and air-breathing jet engines for high-speed flight vehicles are studied within the framework of supersonic small perturbation theory.Both the influence of airframe components on air intakes performance and influence of intakes on vehicle external aerodynamics are under consideration.Analytical relations and specific examples show that significant favorable interference between airframes and air intakes can be realized by using preliminary compression of the flow in front of intakes at flight Mach numbers exceeding approximately 3.

Comparative performance analysis of combinedcycle pulse detonation turbofan engines (PDTEs)

Combined-cycle pulse detonation engines are promising contenders for hypersonic propulsion systems.In the present study,design and propulsive performance analysis of combined-cycle pulse detonation turbofan engines(PDTEs)is presented.Analysis is done with respect to Mach number at two consecutive modes of operation:(1)Combined-cycle PDTE using a pulse detonation afterburner mode(PDA-mode)and(2)combined-cycle PDTE in pulse detonation ramjet engine mode(PDRE-mode).The performance of combined-cycle PDTEs is compared with baseline afterbuming turbofan and ramjet engines.The comparison of afterburning modes is done for Mach numbers from 0 to 3 at 15.24 km altitude conditions,while that of pulse detonation ramjet engine(PDRE)is done for Mach 1.5 to Mach 6 at 18.3 km altitude conditions.The analysis shows that the propulsive performance of a tubine engine can be greatly improved by replacing the conventional afterbumer with a pulse detonation afterburner(PDA).The PDRE also outperforms its ramjet counterpart at all flight conditions considered herein.The gains obtained are outstanding for both the combined-cycle PDTE modes compared to baseline turbofan and ramjet engines.

Control-oriented Modeling for Air-breathing Hypersonic Vehicle Using Parameterized Configuration Approach

This article presents a parameterized configuration modeling approach to develop a 6 degrees of freedom （DOF） rigid-body model for air-breathing hypersonic vehicle （AHV）. The modeling process involves the parameterized configuration design, inviscous hypersonic aerodynamic force calculation and scramjet engine modeling. The parameters are designed for airframe-propulsion integration configuration, the aerodynamic force calculation is based on engineering experimental methods, and the engine model is acquired from gas dynamics and quasi-one dimensional combustor calculations. Multivariate fitting is used to obtain analytical equations for aerodynamic force and thrust. Furthermore, the fitting accuracy is evaluated by relative error （RE）. Trim results show that the model can be applied to the investigation of control method for AHV during the cruise phase. The modeling process integrates several disciplines such as configuration design, aerodynamic calculation, scramjet modeling and control method. Therefore the modeling method makes it possible to conduct AHV aerodynamics/propulsion/control integration design.

Recent research progress on airbreathing aero-engine control algorithm

Airbreathing aero-engines are regarded as excellent propulsion devices from ground takeoff to hypersonic flight,and require control systems to ensure their efficient and safe operation.Therefore,the present paper aims to provide a summary report of recent research progress on airbreathing aero-engine control to help researchers working on this topic.First,five control problems of airbreathing aero-engines are classified:uncertainty problem,multiobjective and multivariable control,fault-tolerant control,distributed control system,and airframe/propulsion integrated control system.Subsequently,the research progress of aircraft gas turbine engine modelling,linear control,nonlinear control,and intelligent control is reviewed,and the advantages and disadvantages of various advanced control algorithms in aircraft gas turbine engines is discussed.Third,several typical hypersonic flight tests are investigated,and the modelling and control issues of dual-mode scramjet are examined.Fourth,modelling,mode transition control and thrust pinch control for turbine-based combined cycle engines are introduced.Followed,significant hypersonic airframe/propulsion integrated system control is analysed.Finally,the study provides specific control research topics that require attention on airbreathing aero-engines.