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, 2001
This work presents an analytic solution to the nonsimple flow of combined friction and area chang... more This work presents an analytic solution to the nonsimple flow of combined friction and area change as a tool for analytically determining the performance efficiency of a generic single PW-100 engine inlet as might be used on the F-16. Solution of the one-dimensional steady compressible flow equations is common only in closed analytic form for the simple flows. An analytic solution of any given combination of the nonlinear differential equations for nonsimple flows has not been thoroughly proven in the open literature. In this work, a method for separating the variables in the nonsimple flow of combined friction and area change is presented as a function of the nozzle divergence angle. A polytropic equation system is thus presented here as a function of roughness, specific heats ratio, Mach and geometric properties. This is valid for the
International Journal of Turbo and Jet Engines, 2003
Geometrically variable converging-diverging thrust-vectoring nozzles, such as the two-dimensional... more Geometrically variable converging-diverging thrust-vectoring nozzles, such as the two-dimensional pitch-only type on the F-22 and the axisymmetric yaw-pitch type tested in the F-15 ACTIV program, directly affect the jet flow geometry and rotation angle at the nozzle exit, thus altering the nozzle aerodynamic performance as a function of geometry, pressure ratio and flight velocity. When the nozzle is rotated at the throat, the effective nozzle expansion length and divergent volume are reduced from the actual geometric nozzle expansion length and divergent volume as a function of the nozzle area control ratio. This defines new nozzle performance characteristics at each vectoring position. The consideration of nozzle divergence and dynamic nozzle geometry dictating the effective-geometric nozzle relation during thrust-vectoring is investigated here. In this study an explicit algorithm is presented as a function of nozzle geometry only, at constant nozzle pressure ratio, zero velocity and altitude. Comparison of the theoretical prediction of the algorithm with experimental data of four axisymmetric thrust-vectoring nozzle configurations verifies that in the quasi-ideal expansion length nozzle, the algorithm well predicts the effective vectoring angle and flow coefficient. This algorithm is applicable in dynamic thrust-vectoring nozzle design performance predictions and analysis of fixed-or variable-area convergent or convergent-divergent nozzles. In this work, basic examples of several possible nozzle types are given. This algorithm is further applicable for the definition of initial jet flow conditions in numerical VSTOL/'TV jet performance studies and promises to be a key design tool for all applications of thrust-vectoring nozzles whose base-frame is rotated at the throat.
International Journal of Turbo and Jet Engines, 2000
The developing field of thrust-vectoring flight control continues to draw increased interest in b... more The developing field of thrust-vectoring flight control continues to draw increased interest in both academic and industrial circles due to the highly nonlinear nature of the field and real benefits extractable for both military and civil aircraft. Along with apparent increases in maneuverability, thrust-vectoring flight control promises to increase flight safety and emergency control recovery, reduce aircraft weight by eliminating the vertical tail, increase flight range and to reduce takeoff and landing runway requirements. Of particular interest is the vertical takeoff and landing capabilities provided by thrust-vectoring flight control and the jet behavior during various modes of hover and movement. In this work, the FLUENT finite volume code is implemented to study the behavior trend of vectoring a single jet from 0-30° into a crossflow of intensities R = 30, 10 and no crossflow for the first time. It is concluded that the crossflow has a greater affect on the effective vectoring angle and thrust coefficient with increasing nominal vectoring angle. Equations describing the effective vectoring angle and thrust coefficient are provided to allow the academic and designer to consider the external crossflow effect on jet performance in development and design simulations. It is further concluded, that for a height of 2D, the stagnation point of the jet disappears a vectoring angle of about 240 after which the jet is unstable as a vertical support for the aircraft.
International Journal of Turbo and Jet Engines, 2001
Аннотация: Прижизненная критика романа Достоевского «Бесы» мало востребована современными исследо... more Аннотация: Прижизненная критика романа Достоевского «Бесы» мало востребована современными исследователями. Причина очевидна: критики не поняли роман Достоевского. В статье дан анализ отзывов на журнальные публикации и книжную редакцию романа «Бесы» (1871-1873 гг.). Первые отклики появились одновременно с началом публикации романа в 1871 г. В течение двух лет автор читал суждения критиков, которые в той или иной степени влияли на процесс создания романа. Достоевский мог принимать или отвергать критику, но бесследно она не проходила. Активное участие в обсуждении романа приняли фельетонисты и обозреватели газет «Санкт-Петербургские ведомости»
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, 2001
This work presents an analytic solution to the nonsimple flow of combined friction and area chang... more This work presents an analytic solution to the nonsimple flow of combined friction and area change as a tool for analytically determining the performance efficiency of a generic single PW-100 engine inlet as might be used on the F-16. Solution of the one-dimensional steady compressible flow equations is common only in closed analytic form for the simple flows. An analytic solution of any given combination of the nonlinear differential equations for nonsimple flows has not been thoroughly proven in the open literature. In this work, a method for separating the variables in the nonsimple flow of combined friction and area change is presented as a function of the nozzle divergence angle. A polytropic equation system is thus presented here as a function of roughness, specific heats ratio, Mach and geometric properties. This is valid for the
International Journal of Turbo and Jet Engines, 2003
Geometrically variable converging-diverging thrust-vectoring nozzles, such as the two-dimensional... more Geometrically variable converging-diverging thrust-vectoring nozzles, such as the two-dimensional pitch-only type on the F-22 and the axisymmetric yaw-pitch type tested in the F-15 ACTIV program, directly affect the jet flow geometry and rotation angle at the nozzle exit, thus altering the nozzle aerodynamic performance as a function of geometry, pressure ratio and flight velocity. When the nozzle is rotated at the throat, the effective nozzle expansion length and divergent volume are reduced from the actual geometric nozzle expansion length and divergent volume as a function of the nozzle area control ratio. This defines new nozzle performance characteristics at each vectoring position. The consideration of nozzle divergence and dynamic nozzle geometry dictating the effective-geometric nozzle relation during thrust-vectoring is investigated here. In this study an explicit algorithm is presented as a function of nozzle geometry only, at constant nozzle pressure ratio, zero velocity and altitude. Comparison of the theoretical prediction of the algorithm with experimental data of four axisymmetric thrust-vectoring nozzle configurations verifies that in the quasi-ideal expansion length nozzle, the algorithm well predicts the effective vectoring angle and flow coefficient. This algorithm is applicable in dynamic thrust-vectoring nozzle design performance predictions and analysis of fixed-or variable-area convergent or convergent-divergent nozzles. In this work, basic examples of several possible nozzle types are given. This algorithm is further applicable for the definition of initial jet flow conditions in numerical VSTOL/'TV jet performance studies and promises to be a key design tool for all applications of thrust-vectoring nozzles whose base-frame is rotated at the throat.
International Journal of Turbo and Jet Engines, 2000
The developing field of thrust-vectoring flight control continues to draw increased interest in b... more The developing field of thrust-vectoring flight control continues to draw increased interest in both academic and industrial circles due to the highly nonlinear nature of the field and real benefits extractable for both military and civil aircraft. Along with apparent increases in maneuverability, thrust-vectoring flight control promises to increase flight safety and emergency control recovery, reduce aircraft weight by eliminating the vertical tail, increase flight range and to reduce takeoff and landing runway requirements. Of particular interest is the vertical takeoff and landing capabilities provided by thrust-vectoring flight control and the jet behavior during various modes of hover and movement. In this work, the FLUENT finite volume code is implemented to study the behavior trend of vectoring a single jet from 0-30° into a crossflow of intensities R = 30, 10 and no crossflow for the first time. It is concluded that the crossflow has a greater affect on the effective vectoring angle and thrust coefficient with increasing nominal vectoring angle. Equations describing the effective vectoring angle and thrust coefficient are provided to allow the academic and designer to consider the external crossflow effect on jet performance in development and design simulations. It is further concluded, that for a height of 2D, the stagnation point of the jet disappears a vectoring angle of about 240 after which the jet is unstable as a vertical support for the aircraft.
International Journal of Turbo and Jet Engines, 2001
Аннотация: Прижизненная критика романа Достоевского «Бесы» мало востребована современными исследо... more Аннотация: Прижизненная критика романа Достоевского «Бесы» мало востребована современными исследователями. Причина очевидна: критики не поняли роман Достоевского. В статье дан анализ отзывов на журнальные публикации и книжную редакцию романа «Бесы» (1871-1873 гг.). Первые отклики появились одновременно с началом публикации романа в 1871 г. В течение двух лет автор читал суждения критиков, которые в той или иной степени влияли на процесс создания романа. Достоевский мог принимать или отвергать критику, но бесследно она не проходила. Активное участие в обсуждении романа приняли фельетонисты и обозреватели газет «Санкт-Петербургские ведомости»
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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Papers by Erich Wilson