Effect of Thrust Vectoring on Aircraft Post - Stall Trims, Stability, and Maneuvers

High performance airplanes require maneuvering at high rates and under conditions of high incidence where the dynamics can be extremely nonlinear and is often accompanied by control input saturation, thereby limiting the igh t envelope. In recent times, the urge to expand the igh t envelope, beyond that achievable using aerodynamic control surfaces, has been addressed using thrust vectoring due to its superior characteristics at high angles of attack. In this paper, eectiv eness of thrust vectoring as a control input has been discussed in detail. Improvement in the post-stall angle of attack capture using thrust vectoring on saturation of aerodynamic controls has been demonstrated by extended bifurcation analysis. Furthermore, the eect of control input saturation on stability of closed-loop airplane dynamics has been illustrated. Key maneuvers, such as turns, have been analyzed in detail to demonstrate eectiv eness of closed-loop in stabilizing otherwise unstable openloop turn trims. Instantaneous turn maneuver has been remodeled to incorporate realistic eects of throttle saturation and negative specic excess power on maximum achievable turn rate. Improvement in the instantaneous turn rate with thrust vectoring is qualied and quantied. Finally, using thrust vectoring, controlled departure and subsequent recovery to level igh t is simulated for igh t instabilities as pitch bucking and oscillatory spin.

[1]  Mikhail Goman,et al.  Application of bifurcation methods to nonlinear flight dynamics problems , 1997 .

[2]  Mario Asselin,et al.  An Introduction to Aircraft Performance , 1997 .

[3]  James Planeaux.  Thrust contributions to the spin characteristics of a model fighter aircraft , 1991 .

[4]  S. Strogatz.  Nonlinear Dynamics and Chaos: With Applications to Physics, Biology, Chemistry and Engineering , 1995 .

[5]  Nandan Kumar Sinha,et al.  Level Flight Trim and Stability Analysis Using Extended Bifurcation and Continuation Procedure , 2001 .

[6]  James Planeaux,et al.  Bifurcation analysis of a model fighter aircraft with control augmentation , 1990 .

[7]  John David Anderson,et al.  Aircraft performance and design , 1998 .

[8]  W. B. Herbst,et al.  Dynamics of Air Combat , 1983 .

[9]  P. R. Smith,et al.  Using Bifurcation Methods to Aid Nonlinear Dynamic Inversion Control Law Design , 1998 .

[10]  Yogesh C. Patel,et al.  Piloted simulation tools for aircraft departure analysis , 1998, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[11]  Eugene L. Allgower,et al.  Numerical continuation methods - an introduction , 1990, Springer series in computational mathematics.

[12]  William L. Garrard,et al.  Nonlinear inversion flight control for a supermaneuverable aircraft , 1992 .

[13]  Raman K. Mehra,et al.  Bifurcation Analysis of Nonlinear Aircraft Dynamics , 1982 .

[14]  N. Ananthkrishnan,et al.  Aircraft Spin Recovery, with and without Thrust Vectoring, Using Nonlinear Dynamic Inversion , 2005 .

[15]  Nguyen X Vinh,et al.  Flight Mechanics of High-Performance Aircraft , 1995 .

[16]  M. S. Francis,et al.  The X-31 aircraft: Advances in aircraft agility and performance , 1996 .

[17]  Thomas F. Fairgrieve,et al.  AUTO 2000 : CONTINUATION AND BIFURCATION SOFTWARE FOR ORDINARY DIFFERENTIAL EQUATIONS (with HomCont) , 1997 .

[18]  C. E. Lan,et al.  Effect of thrust vectoring on level-turn performance , 1992 .

[19]  N. Ananthkrishnan,et al.  Airplane Level Turn Performance, Including Stability Constraints, Using EBAC Method , 2005 .

[20]  Wayne C. Durham.  Constrained Control Allocation , 1992 .

[21]  E. Allgower,et al.  Numerical Continuation Methods , 1990 .

[22]  C. Michael Fremaux.  Spin-Tunnel Investigation of a 1/28-Scale Model of the NASA F-18 High Alpha Research Vehicle (HARV) with and without Vertical Tails , 1997 .

[23]  George W. Watt,et al.  Minimum-time turns using vectored thrust , 1989 .

[24]  Joseph W. Pahle,et al.  Thrust Vectoring on the NASA F-18 High Alpha Research Vehicle , 1996 .

[25]  Giulio Avanzini,et al.  Bifurcation Analysis of a Highly Augmented Aircraft Model , 1997 .

[26]  Benjamin Gal-Or,et al.  Maximizing thrust-vectoring control power and agility metrics , 1992 .

[27]  E. H. Miller,et al.  Performance of a forward swept wing fighter utilizing thrust vectoring and reversing , 1986 .