Thrust-vectoring flight control is a leading-edge technology now being implemented in production ... more Thrust-vectoring flight control is a leading-edge technology now being implemented in production aircraft such as the F-22, Su-37 and MiG 35. It significantly increases aircraft maneuverability and capability through enabling the use of jet-deflection as an alternative or enhancement to conventional aircraft flight control. Analytical modeling of thrust-vectoring nozzles has been at best fragmentary in publicly available literature in the past. For robust nozzle modeling not only the internal fluid mechanics need to be considered, but the dynamic geometry of the nozzle as well as the influence on the forces obtained from the jet by the flight velocity and angle of attack of the aircraft. With the fervent research into vertical flight capabilities as in the Joint Strike Fighter program, among other aircraft, the influence of the ground effect on the jet must also be considered. In all of this, the foundation of analysis lies in the understanding and modeling of aircraft nozzle perfor...
International Journal of Turbo and Jet Engines, 1999
... Wilson, Dan Adler, Benjamin Z. Gal-Or, Valery Sherbaum and Michael Lichtsinder ... prior to t... more ... Wilson, Dan Adler, Benjamin Z. Gal-Or, Valery Sherbaum and Michael Lichtsinder ... prior to the throat (Su-37), at the throat of the nozzle (Gal-Or, Matesanz et al.), or by the addition of various external paddle-type deflectors around the exit of the nozzle (Capone /4/, Johnson /12 ...
A polytropic analytical equation system for the internal flow of nozzles, inlets, and ducts has b... more A polytropic analytical equation system for the internal flow of nozzles, inlets, and ducts has been developed through an analysis of the compressible flow equations including the friction and area change driving potentials. These equations are verified through comparison with experimental data and numerical simulations using FLUENT 5.0. The nozzle performance predictions include consideration of the nozzle divergence and surface roughness. It is demonstrated that the analytical model well matches the experimental data after the throat is fully choked. The numerical and analytical results are compared and discussed. Such an analytical model is extremely useful in bridging the gap between accepted empirical parameters such as the friction factor, performance coefficients, and analytical performance modeling. Furthermore, it provides the first analytical model for thrust-vectoring nozzle performance predictions. In aircraft nozzle simulations where empirical data may not be available, this model provides good simulation capability.
ABSTRACT Engine thrust vectoring (TV) is a potential technology for military and future civil air... more ABSTRACT Engine thrust vectoring (TV) is a potential technology for military and future civil aircraft in which the Technion-Israel Institute of Technology has made significant contributions. This paper provides realistic predictions of steady-state engine performance during steady-state pitch vectoring. The results obtained comprise a required fundamental step for advanced aircraft/TV implementation. This work is a part of the Lockheed Martin yaw-pitch TV F-16/F-100 research study conducted here at the Jet Laboratory. To this end, a unique TV-engine computer algorithm has been developed that expands the conventional steady-state modeling capabilities of on- and off-design as well as the conventional transients (via throttle changes) to create steady-state and dynamic TV-engine simulations at various altitudes and Mach numbers. This paper reviews the steady state performances and the optimization observations initially obtained. The subcritical flow realm of nozzle performance provides trends aiding in the prediction of thrust benefits beyond the conventional nozzle design of the F100 model are available as the effective nozzle throat area is allowed to contract through vectoring.
A polytropic analytical equation system for the internal e ow of nozzles and ducts has been devel... more A polytropic analytical equation system for the internal e ow of nozzles and ducts has been developed by a solution to the combined friction/area change compressible e ow equations. Validation of the system is sought through comparison with experimental data and numerical simulations using FLUENT in the prediction of the performances of two conventional axisymmetric nozzles. Analytical performance coefe cient equations have been developed from the polytropic equation system for this purpose. The predictions with consideration of nozzle divergence angle and roughness are presented for the e rst time. It is demonstrated that the analytical model well matches the experimental data after the throat is fully choked. The numerical and analytical results are compared and discussed. Such an analytical model is extremely useful in bridging the gap between accepted empirical parameters, such as the friction factor and performance factors, and analytical performance modeling. In aircraft nozzle simulations, where empirical data may not be available, this model provides more precise simulation capability especially applicable to modern thrust-vectoring nozzles.
Thrust-vectoring flight control is a leading-edge technology now being implemented in production ... more Thrust-vectoring flight control is a leading-edge technology now being implemented in production aircraft such as the F-22, Su-37 and MiG 35. It significantly increases aircraft maneuverability and capability through enabling the use of jet-deflection as an alternative or enhancement to conventional aircraft flight control. Analytical modeling of thrust-vectoring nozzles has been at best fragmentary in publicly available literature in the past. For robust nozzle modeling not only the internal fluid mechanics need to be considered, but the dynamic geometry of the nozzle as well as the influence on the forces obtained from the jet by the flight velocity and angle of attack of the aircraft. With the fervent research into vertical flight capabilities as in the Joint Strike Fighter program, among other aircraft, the influence of the ground effect on the jet must also be considered. In all of this, the foundation of analysis lies in the understanding and modeling of aircraft nozzle perfor...
International Journal of Turbo and Jet Engines, 1999
... Wilson, Dan Adler, Benjamin Z. Gal-Or, Valery Sherbaum and Michael Lichtsinder ... prior to t... more ... Wilson, Dan Adler, Benjamin Z. Gal-Or, Valery Sherbaum and Michael Lichtsinder ... prior to the throat (Su-37), at the throat of the nozzle (Gal-Or, Matesanz et al.), or by the addition of various external paddle-type deflectors around the exit of the nozzle (Capone /4/, Johnson /12 ...
A polytropic analytical equation system for the internal flow of nozzles, inlets, and ducts has b... more A polytropic analytical equation system for the internal flow of nozzles, inlets, and ducts has been developed through an analysis of the compressible flow equations including the friction and area change driving potentials. These equations are verified through comparison with experimental data and numerical simulations using FLUENT 5.0. The nozzle performance predictions include consideration of the nozzle divergence and surface roughness. It is demonstrated that the analytical model well matches the experimental data after the throat is fully choked. The numerical and analytical results are compared and discussed. Such an analytical model is extremely useful in bridging the gap between accepted empirical parameters such as the friction factor, performance coefficients, and analytical performance modeling. Furthermore, it provides the first analytical model for thrust-vectoring nozzle performance predictions. In aircraft nozzle simulations where empirical data may not be available, this model provides good simulation capability.
ABSTRACT Engine thrust vectoring (TV) is a potential technology for military and future civil air... more ABSTRACT Engine thrust vectoring (TV) is a potential technology for military and future civil aircraft in which the Technion-Israel Institute of Technology has made significant contributions. This paper provides realistic predictions of steady-state engine performance during steady-state pitch vectoring. The results obtained comprise a required fundamental step for advanced aircraft/TV implementation. This work is a part of the Lockheed Martin yaw-pitch TV F-16/F-100 research study conducted here at the Jet Laboratory. To this end, a unique TV-engine computer algorithm has been developed that expands the conventional steady-state modeling capabilities of on- and off-design as well as the conventional transients (via throttle changes) to create steady-state and dynamic TV-engine simulations at various altitudes and Mach numbers. This paper reviews the steady state performances and the optimization observations initially obtained. The subcritical flow realm of nozzle performance provides trends aiding in the prediction of thrust benefits beyond the conventional nozzle design of the F100 model are available as the effective nozzle throat area is allowed to contract through vectoring.
A polytropic analytical equation system for the internal e ow of nozzles and ducts has been devel... more A polytropic analytical equation system for the internal e ow of nozzles and ducts has been developed by a solution to the combined friction/area change compressible e ow equations. Validation of the system is sought through comparison with experimental data and numerical simulations using FLUENT in the prediction of the performances of two conventional axisymmetric nozzles. Analytical performance coefe cient equations have been developed from the polytropic equation system for this purpose. The predictions with consideration of nozzle divergence angle and roughness are presented for the e rst time. It is demonstrated that the analytical model well matches the experimental data after the throat is fully choked. The numerical and analytical results are compared and discussed. Such an analytical model is extremely useful in bridging the gap between accepted empirical parameters, such as the friction factor and performance factors, and analytical performance modeling. In aircraft nozzle simulations, where empirical data may not be available, this model provides more precise simulation capability especially applicable to modern thrust-vectoring nozzles.
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