The transient performance of the selective bleed variable cycle engine (VCE) has been optimized during the transition from subsonic to supersonic mode. The selective bleed VCE concept has been developed with a short take-off vertical landing (STOVL) aircraft in mind and the engine is characterized by its twin mode VCE feature. The transition optimization is constrained by the requirement of maintaining thrust and compressor surge margins. The engine variable geometry component schedules and the fuel flow are used as optimization variables. A differential algebraic formulation of an inter-component volume model is used to model the transient behavior of the engine. Sequential quadratic programming (SQP) is applied to the nonlinear transient engine model directly, in order to solve the multivariable control problem. It is predicted that the mode switch can be carried out safely without violating the constraints and that the time required is limited by the actuator time of the hydraulic system.

Issue Section:
Gas Turbines: Cycle Innovations
Keywords:
aircraft, aerospace engines, hydraulic systems, modelling
Topics:
Cycles, Engines, Optimization, Transients (Dynamics), Aircraft, Thrust, Geometry, Design
1.
Nascimento, M. A. R., and Pilidis, P., 1991, “The Selective Bleed Variable Cycle Engine,” ASME Paper 91-GT-388.
2.
Nascimento, M. A. R., 1992, “The Selective Bleed Variable Cycle Engine,” Ph.D. thesis, Cranfield Institute of Technology.
3.
Ulizar, I., and Pilidis, P., 1995, “Transition Control and Performance of the Selective Bleed Variable Cycle Turbofan,” ASME Paper 95-GT-286.
4.
Oggero, L., and Pilidis, P., 1998, “A Novel Optimization Method for Variable Cycle Engines,” ASME Paper 98-GT-142.
5.
Gro¨nstedt, U. T. J., 2000, “Development of Methods for Analysis and Optimization of Complex Jet Engine Systems,” Ph.D. thesis, Chalmers University of Technology.
6.
Gill, P. E., Murray, W., Saunders, M. A., Hammarling, S. J., and Wright, M. H., 1986, “Users guide for LSSOL,” Department of Operations Research, Stanford University, Report, SOL 86-1.
7.
Gro¨nstedt, U. T. J., 1999, “Advanced Solvers for General High Performance Transient Gas Turbine Simulation Tools,” 14th International Symposium on Air Breathing Engines, Florence, Italy.
8.
Petzold, L. R., 1983, “A Description of DASSL: A Differential/Algebraic System Solver,” Scientific Computing, R. S. Stepleman et al., eds. North-Holland, Amsterdam, pp. 65–68.
9.
Brenan, K. E., Campbell, S. L., and Petzold, L. R., 1989, Numerical Solution of Initial-Value Problems in Differential-Algebraic Equations, Elsevier, New York.
10.
Gro¨nstedt, U. T. J., 1997, “Mission Dependent Optimization of Advanced Fighter Engines,” 13th International Symposium on Air Breathing Engines, Chattanooga, TN.
11.
Daniele, C. J., Krosel, M. S., John, R. S., and Westerkamp, E. J., 1983, “Digital Computer Program for Generating Dynamic Turbofan Engine Models (DIGTEM),” NASA-TM-83446.
12.
Chappel
,
M. A.
, and
McLaughlin
,
P. W.
,
1993
, “
Approach to Modeling Continuous Turbine Engine Operation from Startup to Shutdown
,”
J. Propul. Power
,
9
, pp.
466
–
471
.
13.
Schobeiri
,
M. T.
,
Attia
,
M.
, and
Lippke
,
C.
,
1994
, “
GE-TRAN: A Generic, Modularly Structured Computer Code for Simulation of Dynamic Behavior of Aero- and Power Generation Gas Turbine Engines
,”
ASME J. Eng. Gas Turbines Power
,
116
, pp.
483
–
494
.
14.
Garrard, D., Davis, M., Jr., Hale, A., Chalk, J., and Savelle, S., 1997, “Analysis of Gas Turbine Engine Operability With the Aerodynamic Turbine Engine Code,” ISABE97-7034, Chattanooga, TN, pp. 223–232.
15.
Dierckx, P., 1993, Curve and Surface Fitting With Splines, Oxford University Press, New York.
Copyright © 2002
 by ASME
You do not currently have access to this content.