The Experts below are selected from a list of 2316 Experts worldwide ranked by ideXlab platform

Kenichi Rinoie - One of the best experts on this subject based on the ideXlab platform.

  • aerodynamic interference caused by the inboard Leading Edge Flap on the outboard area of the cranked arrow wing
    Procedia Engineering, 2015
    Co-Authors: Kosuke Toyoda, Dong-youn Kwak, Masayoshi Noguchi, Kenichi Rinoie
    Abstract:

    Abstract Wind tunnel tests were conducted on a cranked arrow wing model to reveal the relationship between the inboard Leading Edge Flaps and vortex behavior formed on the outboard wing area. Aerodynamic force measurements and flow visualizations on the upper surface of the wing were made. The pitching moment characteristics indicate that there are two non-linear changes and the flow patterns which caused those changes are observed. The flow patterns indicate that the non-linear changes are caused both by the flow separation on the outside of the inboard vortex and by the one on the outside of the merging position of the inboard and outboard vortices. It was found that the inboard Leading Edge Flap decreases the angle of attack when recovery from the first change occurs. The inboard Leading Edge Flap also causes an increase in the magnitude of the second change.

  • experimental optimization of Leading Edge deflection angles for an sst configuration at low speed
    51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2013
    Co-Authors: Zhong Lei, Dong-youn Kwak, Kenichi Rinoie
    Abstract:

    An experimental study has been conducted for a segmented Flap system of a cranked-arrow wing in a low-speed wind tunnel. The objectives were to investigate effects of a multi-segmented Flap system on the aerodynamic performance, and search an optimum combination of Flap deflection angles at takeoff and landing conditions. The wind tunnel model was a supersonic transport configuration with the Leading-Edge Flap which was divided into four segments, and a trailing-Edge Flap to achieve better aerodynamic performance. In this paper, effects of deflection angle of Flap segments on drag reduction and lift-to-drag ratio improvement will be discussed at interested lift coefficients. Analysis of experimental data indicated that the segmented Flaps were more effective than the uniformly-deflected Flaps and an optimal combination of Flap deflection angles improves the aerodynamic performance.

  • vortex behaviors of rolled supersonic transport configuration with Leading Edge Flaps
    Journal of Aircraft, 2006
    Co-Authors: Kenichi Rinoie, Masashi Shirotake, Dong-youn Kwak
    Abstract:

    Wind tunnel measurements were done to investigate the effect of Leading-Edge Flaps on the rolling moment characteristics of the cranked arrow wing for the supersonic transport. Static rolling moment measurements, flow visualization studies, and crossflow velocity measurements by a particle image velocimetry were made at Re = 6.2 x 104. Static rolling moment measurements confirmed linear restoring moment at « < 16deg for the models both with and without Flap deflection. When the outboard Leading-Edge Flap is deflected 12 deg, rolling moment hysteresis is observed at the roll angle of 0 as 20 deg and α ≈ 20 deg. The experimental results indicate that the hysteresis is caused by different vortex breakdown behaviors on the inboard wing when the wing is rotated in the clockwise and counterclockwise directions.

  • lift to drag ratio improvement on a supersonic transport by Leading Edge Flap at transonic regions
    Journal of The Japan Society for Aeronautical and Space Sciences, 2004
    Co-Authors: Dong-youn Kwak, Katsuhiro Miyata, Masayoshi Noguchi, Kenji Yoshida, Kenichi Rinoie
    Abstract:

    Wind tunnel tests were conducted to investigate lift to drag ratio improvement by the Leading-Edge Flap the outboard wing on an SST model at transonic regions. Force measurements and surface pressure measurements were performed for the SST model with and without outboard Leading-Edge Flaps of 5 and 12.2 degrees deflection angles. The lift to drag ratio was improved due to a reduction in the drag component when Flaps deflected, because the flow was attached to the Leading Edge surface of the wing. The optimum Flap deflection angles to attain the maximum lift to drag ratio at a fixed lift coefficient were estimated using experimental results.

  • lift to drag ratio improvement of a supersonic transport with Leading Edge and trailing Edge Flaps
    Journal of The Japan Society for Aeronautical and Space Sciences, 2003
    Co-Authors: Dong-youn Kwak, Katsuhiro Miyata, Masayoshi Noguchi, Kenichi Rinoie
    Abstract:

    Wind tunnel tests were conducted to investigate aerodynamic characteristics of a Supersonic Transport (SST) model with Leading-Edge and trailing-Edge Flaps. Force and surface pressure measurements were performed for the SST model either with Leading-Edge Flaps or with trailing-Edge Flaps deflected and for the model with all the Flaps deflected. The lift-to-drag ratio (L/D) can be improved by the Leading-Edge Flap deflection. When the trailing-Edge Flap is deflected modestly, the L/D is also improved. According to the measured results, the best improvement of the L/D is attained when the Leading-Edge and trailing-Edge Flaps are deflected at the same time. This paper discusses how the combination of Leading-Edge and trailing-Edge Flaps improves the wing performance.

Dong-youn Kwak - One of the best experts on this subject based on the ideXlab platform.

  • aerodynamic interference caused by the inboard Leading Edge Flap on the outboard area of the cranked arrow wing
    Procedia Engineering, 2015
    Co-Authors: Kosuke Toyoda, Dong-youn Kwak, Masayoshi Noguchi, Kenichi Rinoie
    Abstract:

    Abstract Wind tunnel tests were conducted on a cranked arrow wing model to reveal the relationship between the inboard Leading Edge Flaps and vortex behavior formed on the outboard wing area. Aerodynamic force measurements and flow visualizations on the upper surface of the wing were made. The pitching moment characteristics indicate that there are two non-linear changes and the flow patterns which caused those changes are observed. The flow patterns indicate that the non-linear changes are caused both by the flow separation on the outside of the inboard vortex and by the one on the outside of the merging position of the inboard and outboard vortices. It was found that the inboard Leading Edge Flap decreases the angle of attack when recovery from the first change occurs. The inboard Leading Edge Flap also causes an increase in the magnitude of the second change.

  • experimental optimization of Leading Edge deflection angles for an sst configuration at low speed
    51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2013
    Co-Authors: Zhong Lei, Dong-youn Kwak, Kenichi Rinoie
    Abstract:

    An experimental study has been conducted for a segmented Flap system of a cranked-arrow wing in a low-speed wind tunnel. The objectives were to investigate effects of a multi-segmented Flap system on the aerodynamic performance, and search an optimum combination of Flap deflection angles at takeoff and landing conditions. The wind tunnel model was a supersonic transport configuration with the Leading-Edge Flap which was divided into four segments, and a trailing-Edge Flap to achieve better aerodynamic performance. In this paper, effects of deflection angle of Flap segments on drag reduction and lift-to-drag ratio improvement will be discussed at interested lift coefficients. Analysis of experimental data indicated that the segmented Flaps were more effective than the uniformly-deflected Flaps and an optimal combination of Flap deflection angles improves the aerodynamic performance.

  • vortex behaviors of rolled supersonic transport configuration with Leading Edge Flaps
    Journal of Aircraft, 2006
    Co-Authors: Kenichi Rinoie, Masashi Shirotake, Dong-youn Kwak
    Abstract:

    Wind tunnel measurements were done to investigate the effect of Leading-Edge Flaps on the rolling moment characteristics of the cranked arrow wing for the supersonic transport. Static rolling moment measurements, flow visualization studies, and crossflow velocity measurements by a particle image velocimetry were made at Re = 6.2 x 104. Static rolling moment measurements confirmed linear restoring moment at « < 16deg for the models both with and without Flap deflection. When the outboard Leading-Edge Flap is deflected 12 deg, rolling moment hysteresis is observed at the roll angle of 0 as 20 deg and α ≈ 20 deg. The experimental results indicate that the hysteresis is caused by different vortex breakdown behaviors on the inboard wing when the wing is rotated in the clockwise and counterclockwise directions.

  • lift to drag ratio improvement on a supersonic transport by Leading Edge Flap at transonic regions
    Journal of The Japan Society for Aeronautical and Space Sciences, 2004
    Co-Authors: Dong-youn Kwak, Katsuhiro Miyata, Masayoshi Noguchi, Kenji Yoshida, Kenichi Rinoie
    Abstract:

    Wind tunnel tests were conducted to investigate lift to drag ratio improvement by the Leading-Edge Flap the outboard wing on an SST model at transonic regions. Force measurements and surface pressure measurements were performed for the SST model with and without outboard Leading-Edge Flaps of 5 and 12.2 degrees deflection angles. The lift to drag ratio was improved due to a reduction in the drag component when Flaps deflected, because the flow was attached to the Leading Edge surface of the wing. The optimum Flap deflection angles to attain the maximum lift to drag ratio at a fixed lift coefficient were estimated using experimental results.

  • lift to drag ratio improvement of a supersonic transport with Leading Edge and trailing Edge Flaps
    Journal of The Japan Society for Aeronautical and Space Sciences, 2003
    Co-Authors: Dong-youn Kwak, Katsuhiro Miyata, Masayoshi Noguchi, Kenichi Rinoie
    Abstract:

    Wind tunnel tests were conducted to investigate aerodynamic characteristics of a Supersonic Transport (SST) model with Leading-Edge and trailing-Edge Flaps. Force and surface pressure measurements were performed for the SST model either with Leading-Edge Flaps or with trailing-Edge Flaps deflected and for the model with all the Flaps deflected. The lift-to-drag ratio (L/D) can be improved by the Leading-Edge Flap deflection. When the trailing-Edge Flap is deflected modestly, the L/D is also improved. According to the measured results, the best improvement of the L/D is attained when the Leading-Edge and trailing-Edge Flaps are deflected at the same time. This paper discusses how the combination of Leading-Edge and trailing-Edge Flaps improves the wing performance.

Victor R Lessard - One of the best experts on this subject based on the ideXlab platform.

  • subsonic investigation of Leading Edge Flaps designed for vortex and attached flow on a high speed civil transport configuration
    1999
    Co-Authors: Bryan A Campbell, Guy T Kemmerly, Kevin J Kjerstad, Victor R Lessard
    Abstract:

    A wind tunnel investigation of two separate Leading-Edge Flaps, designed for vortex and attached-flow, respectively, were conducted on a High Speed Civil Transport (HSCT) configuration in the Langley 14- by 22-Foot Subsonic Tunnel. Data were obtained over a Mach number range of 0.12 to 0.27, with corresponding chord Reynolds numbers of 2.50 x 10 (sup 6) to 5.50 x 10 (sup 6). Variations of the Leading-Edge Flap deflection angle were tested with outboard Leading-Edge Flaps deflected 0 deg. and 26.4 deg. Trailing-Edge Flaps were deflected 0 deg., 10 deg., 12.9 deg., and 20 deg. The longitudinal and lateral aerodynamic data are presented without analysis. A complete tabulated data listing is also presented herein. The data associated with each deflected Leading-Edge Flap indicate L/D improvements over the undeflected configuration. These improvements may be instrumental in providing the necessary lift augmentation required by an actual HSCT during the climb-out and landing phases of the flight envelope. However, further tests will have to be done to assess their full potential.

  • subsonic investigation of Leading Edge Flaps designed for vortex and attached flow on a high speed civil transport configuration
    1999
    Co-Authors: Bryan A Campbell, Guy T Kemmerly, Kevin J Kjerstad, Victor R Lessard
    Abstract:

    Summary A wind tunnel investigation of two separate Leading-Edge Flaps, designed for vortex- andattached-flow respectively, were conducted on a High Speed Civil Transport (HSCT) configura-tion in the Langley 14- by 22-Foot Subsonic Tunnel. Data were obtained over a Mach numberrange of 0.12 to 0.27, with corresponding chord Reynolds numbers of 2.50x106 to 5.50x106. Vari-ations of the Leading-Edge Flap deflection angle were tested with outboard Leading-Edge Flapsdeflected 0O and 26.4 °. Trailing-Edge Flaps were deflected 0O, 10°, 12.9 ° and 20 °. The longitudinaland lateral aerodynamic data axe presented without analysis. A complete tabulated data listing isalso presented herein. The data associated with each deflected Leading-Edge Flap indicate L/Dimprovements over the undeflected configuration. These improvements may be instrumental inproviding the necessary lift augmentation required by an actual HSCT during the climb-out andlanding phases of the flight envelope. However, further tests will have to be done to assess theirfull potential.IntroductionProposed High-Speed Civil Transport (HSCT) configurations have supersonic cruise speedsabove Mach 2, and hence incorporate a high degree of Leading-Edge sweep for supersonic cruiseefficiency. However, high Leading-Edge sweep is not conducive to efficient performance at sub-sonic speeds such as encountered during take-off, climbout, approach and landing. Therefore,investigations are continuing at the NASA Langley Research Center to study ways of improvingthe subsonic capabilities of conceptual HSCT configurations.One area of investigation involves the tendency for highly swept wings to develop Leading-Edge vortical flow at moderate to high angles of attack. It has been observed in previous wind tun-nel investigations (references 1 & 2) that during the subsonic climbout phase of the flight enve-lope, these wings tend to produce large upper surface vortex su-ucmres. Although these vorticesmay provide significant lift augmentation, they often result in increased drag and a poorer LtD.Increased drag requires a corresponding increase in engine thrust, thereby adversely affecting thecommunity noise characteristics.Over the years, several methods have been tried to manipulate the vortex flow field on thewings of configurations similar to HSCT concepts in order to improve their low speed perfor-mance (references 3 thru 8). This test investigates the use of two Leading-Edge Flap systems toenhance low-speed, high-lift. The first system, a vortex Flap on the 71 ° inboard section of this1

Bryan A Campbell - One of the best experts on this subject based on the ideXlab platform.

  • subsonic investigation of Leading Edge Flaps designed for vortex and attached flow on a high speed civil transport configuration
    1999
    Co-Authors: Bryan A Campbell, Guy T Kemmerly, Kevin J Kjerstad, Victor R Lessard
    Abstract:

    A wind tunnel investigation of two separate Leading-Edge Flaps, designed for vortex and attached-flow, respectively, were conducted on a High Speed Civil Transport (HSCT) configuration in the Langley 14- by 22-Foot Subsonic Tunnel. Data were obtained over a Mach number range of 0.12 to 0.27, with corresponding chord Reynolds numbers of 2.50 x 10 (sup 6) to 5.50 x 10 (sup 6). Variations of the Leading-Edge Flap deflection angle were tested with outboard Leading-Edge Flaps deflected 0 deg. and 26.4 deg. Trailing-Edge Flaps were deflected 0 deg., 10 deg., 12.9 deg., and 20 deg. The longitudinal and lateral aerodynamic data are presented without analysis. A complete tabulated data listing is also presented herein. The data associated with each deflected Leading-Edge Flap indicate L/D improvements over the undeflected configuration. These improvements may be instrumental in providing the necessary lift augmentation required by an actual HSCT during the climb-out and landing phases of the flight envelope. However, further tests will have to be done to assess their full potential.

  • subsonic investigation of Leading Edge Flaps designed for vortex and attached flow on a high speed civil transport configuration
    1999
    Co-Authors: Bryan A Campbell, Guy T Kemmerly, Kevin J Kjerstad, Victor R Lessard
    Abstract:

    Summary A wind tunnel investigation of two separate Leading-Edge Flaps, designed for vortex- andattached-flow respectively, were conducted on a High Speed Civil Transport (HSCT) configura-tion in the Langley 14- by 22-Foot Subsonic Tunnel. Data were obtained over a Mach numberrange of 0.12 to 0.27, with corresponding chord Reynolds numbers of 2.50x106 to 5.50x106. Vari-ations of the Leading-Edge Flap deflection angle were tested with outboard Leading-Edge Flapsdeflected 0O and 26.4 °. Trailing-Edge Flaps were deflected 0O, 10°, 12.9 ° and 20 °. The longitudinaland lateral aerodynamic data axe presented without analysis. A complete tabulated data listing isalso presented herein. The data associated with each deflected Leading-Edge Flap indicate L/Dimprovements over the undeflected configuration. These improvements may be instrumental inproviding the necessary lift augmentation required by an actual HSCT during the climb-out andlanding phases of the flight envelope. However, further tests will have to be done to assess theirfull potential.IntroductionProposed High-Speed Civil Transport (HSCT) configurations have supersonic cruise speedsabove Mach 2, and hence incorporate a high degree of Leading-Edge sweep for supersonic cruiseefficiency. However, high Leading-Edge sweep is not conducive to efficient performance at sub-sonic speeds such as encountered during take-off, climbout, approach and landing. Therefore,investigations are continuing at the NASA Langley Research Center to study ways of improvingthe subsonic capabilities of conceptual HSCT configurations.One area of investigation involves the tendency for highly swept wings to develop Leading-Edge vortical flow at moderate to high angles of attack. It has been observed in previous wind tun-nel investigations (references 1 & 2) that during the subsonic climbout phase of the flight enve-lope, these wings tend to produce large upper surface vortex su-ucmres. Although these vorticesmay provide significant lift augmentation, they often result in increased drag and a poorer LtD.Increased drag requires a corresponding increase in engine thrust, thereby adversely affecting thecommunity noise characteristics.Over the years, several methods have been tried to manipulate the vortex flow field on thewings of configurations similar to HSCT concepts in order to improve their low speed perfor-mance (references 3 thru 8). This test investigates the use of two Leading-Edge Flap systems toenhance low-speed, high-lift. The first system, a vortex Flap on the 71 ° inboard section of this1

Keller Dennis - One of the best experts on this subject based on the ideXlab platform.

  • High-lift design for a forward swept natural laminar flow wing
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Keller Dennis
    Abstract:

    The scope of the paper is to present the results of a RANS-based aerodynamic high-lift design for a natural laminar flow wing with negative sweep. The chosen high-lift system consists of a Krueger Leading Edge Flap with shielding function and a fixed-vane trailing Edge Flap. The design was first optimized in two main wing sections and then verified by 3D RANS simulations of a wing-body model. Finally, engines were added to the geometric model to estimate the high-lift performance of the landing configuration. With a maximum lift coefficient of C_L,max=2.85 for the wing-body model with engine, the target from the preliminary aircraft design was reached. Further potential for improvement was found in the optimization strategy and the shape of the fuselage--wing junction