Aerodynamic characteristics of NACA 4412 airfoil section with flap in extreme ground effect
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Wing-in-Ground vehicles and aerodynamically assisted boats take advantage of increased lift and reduced drag of wing sections in the ground proximity. At relatively low speeds or heavy payloads of these craft, a flap at the wing trailing-edge can be applied to boost the aerodynamic lift. The influence of a flap on the two-dimensional NACA 4412 airfoil in viscous ground-effect flow is numerically investigated in this study. The computational method consists of a steady-state, incompressible, finite volume method utilizing the Spalart-Allmaras turbulence model. Grid generation and solution of the Navier-Stokes equations are completed using computer program Fluent. The code is validated against published experimental and numerical results of unbounded flow with a flap, as well as ground-effect motion without a flap. Aerodynamic forces are calculated, and the effects of angle of attack, Reynolds number, ground height, and flap deflection are presented for a split and plain flap. Changes in the flow introduced with the flap addition are also discussed. Overall, the use of a flap on wings with small attack angles is found to be beneficial for small flap deflections up to 5% of the chord, where the contribution of lift augmentation exceeds the drag increase, yielding an augmented lift-to-drag ratio.
Abstract
Wing-in-Ground vehicles and aerodynamically assisted boats take advantage of increased lift and reduced drag of wing sections in the ground proximity. At relatively low speeds or heavy payloads of these craft, a flap at the wing trailing-edge can be applied to boost the aerodynamic lift. The influence of a flap on the two-dimensional NACA 4412 airfoil in viscous ground-effect flow is numerically investigated in this study. The computational method consists of a steady-state, incompressible, finite volume method utilizing the Spalart-Allmaras turbulence model. Grid generation and solution of the Navier-Stokes equations are completed using computer program Fluent. The code is validated against published experimental and numerical results of unbounded flow with a flap, as well as ground-effect motion without a flap. Aerodynamic forces are calculated, and the effects of angle of attack, Reynolds number, ground height, and flap deflection are presented for a split and plain flap. Changes in the flow introduced with the flap addition are also discussed. Overall, the use of a flap on wings with small attack angles is found to be beneficial for small flap deflections up to 5% of the chord, where the contribution of lift augmentation exceeds the drag increase, yielding an augmented lift-to-drag ratio.
참고문헌 (28)
- Kikuchi, M., "Measurement of aerofoil characteristics by method of towing", Transactions of the Japan Society of Mechanical Engineers, 68(676), pp.3378~3385 (2002)
- Spalart, P, "A one-equation turbulence model for aerodynamic flows", Proceedings of 29th Aerospace Sciences Meeting (1991)
- Wu, C.K., "High-Reynoldsnumber flow computations for wings in ground effect", Proceedings of 6th International Conference on Fast Sea Transportation (2001)
- Hsiun, C., "Aerodynamic characteristics of a two-dimensional airfoil with ground effect", Journal of Aircraft, 33(2), pp.386~392 (1996)
- Van Dam, C.P., "Recent experience with different methods of drag prediction", Progress in Aerospace Sciences, 35(88), pp.751~798 (1999)
- Huffman, J.K., "Investigation of the static lift capability of a low-aspect-ratio wing operating in a powered ground-effect mode" (1974), NASA Technical Memorandum X-3031
- Katz, J., "Low-Speed Aerodynamics – from Wing Theory to Panel Methods" (1991), McGraw-Hill
- Kirillovykh, V.N, "Transport amphibious platforms: a new type of high-speed craft", Proceedings of Workshop on Ekranoplans and Very Fast Craft, University of New South Wales (1996)
- Kornev, N.V, "Complex numerical modeling of dynamics and crashes of Wing-in-Ground vehicles", Proceedings of 41st Aerospace Sciences Meeting & Exhibit (2003)
- Evaluation of a Power-Augmented-Ram wing operating free in heave and pitch over water, "Krause, F.H.", ~, pp.DTNSRDC Report ASED-385 (1977)
- Matveev, K.I., "Static thrust recovery of PAR craft on solid surfaces", Journal of Fluids and Structures, 24(6), pp.920~926 (2008)
- Rozhdestvensky, K.V., "Aerodynamics of a Lifting System in Extreme Ground Effect" (2000), Springer
- Rozhdestvensky, K.V., "Wing-in-Ground effect vehicles", Progress in Aerospace Sciences, 42, pp.211~283 (2006)
- Rumsey, C.L., "Prediction of high lift: review of present CFD capabilities", Progress in Aerospace Sciences, 38(2), pp.145~180 (2002)
- Serebrisky, Y.M., "Wind-tunnel investigation of the horizontal motion of a wing near the ground", NACA Technical Memorandum, 1095 (1946)
- Steinbach, D., "Some aerodynamic aspects of wings near ground", Transactions of the Japan Society for Aeronautical and Space Sciences, 34(104), pp.56~70 (1991)
- Chun, H., "Turbulence flow simulation for wings in ground effect with two ground conditions: fixed and moving ground", International Journal of Maritime Engineering, 145, pp.51~68 (2003)
- Constantinescu, G, "Turbulence modeling applied to flow over a sphere", AIAA Journal, 41(9), pp.1733~1742 (2003)
- Doolan, C., "Numerical simulation of a blunt airfoil wake using a two-dimensional URANS approach", Proceedings of 16th Australasian Fluid Mechanics Conference, University of Queensland (2007)
- Ferziger, J., "Computational Methods for Fluid Dynamics" (1999), Springer
- Firooz, A., "Turbulence flow for NACA 4412 in unbounded flow and ground effect with different turbulence models and two ground conditions: fixed and moving ground conditions", Proceedings of International Conference on Boundary and Interior Layers (2006)
- "Fluent 6.2: Users manual", ~ (2005)
- Gallington, R.W., "Power augmentation of ram wings", Proceedings of Conference on RAM Wings and Ground Effect Craft (1987)
- Gallington, R.W., "Recent advances in Wing-in-Ground effect vehicle technology", Proceedings of AIAA, 1976, ~
- Hayashi, M., "Measurement of flow fields around an airfoil section with separation", Transactions of the Japan Society for Aeronautical and Space Sciences, 21, pp.69~75 (1978)
- Hirata, N., "Investigation of a threedimensional power-augmented ram wing in ground effect", Proceedings of 35th Aerospace Sciences Meeting & Exhibit, AIAA (1997)
- Abbott, I., "Theory of wing sections" (1959), Dover Publications
- Barber, T., "Appropriate CFD techniques for the prediction of ground effect aerodynamics", Proceedings of Workshop 'WISE up to ekranoplan GEMs', University of New South Wales (1998)