유입 유동의 가속도가 2D 원형실린더의 항력 및 후류에 미치는 영향
Effects of Flow Acceleration on Drag Force and Wake Field of 2D Circular Cylinder
2
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
Computational studies of accelerating flow around 2D Circular Cylinder was performed to investigate characteristics of wake field and drag forces. Previous studies had revealed that drag on the cylindrical body in accelerating flow is much greater than that in the flow with constant velocity; however, the underlying physics on the drag increase has not been clearly investigated. In order to investigate the drag increase and its relationship with wake development, this study employed a finite-volume based CFD code, Fluent 13.0 with SST model for turbulence effects. Inflows are modeled with varied accelerations from 0.4905 to . The drag computed in the present study is in good agreement with previous studies, and clearly shows the increase compared to the drag on the body in the flow with constant velocity. The results also show that drag crisis observed at high Reynolds number in the case of the flow with constant velocity is also found in the case of accelerating flow. The analysis for wake and recirculation length shows that conventional vortex shedding does not occur even at high Reynolds number and the drag increase is larger at higher acceleration.
Abstract
Computational studies of accelerating flow around 2D Circular Cylinder was performed to investigate characteristics of wake field and drag forces. Previous studies had revealed that drag on the cylindrical body in accelerating flow is much greater than that in the flow with constant velocity; however, the underlying physics on the drag increase has not been clearly investigated. In order to investigate the drag increase and its relationship with wake development, this study employed a finite-volume based CFD code, Fluent 13.0 with SST model for turbulence effects. Inflows are modeled with varied accelerations from 0.4905 to . The drag computed in the present study is in good agreement with previous studies, and clearly shows the increase compared to the drag on the body in the flow with constant velocity. The results also show that drag crisis observed at high Reynolds number in the case of the flow with constant velocity is also found in the case of accelerating flow. The analysis for wake and recirculation length shows that conventional vortex shedding does not occur even at high Reynolds number and the drag increase is larger at higher acceleration.
참고문헌 (19)
- Achenbach, E., "Distribution of local pressure and skin friction around a circular cylinder in cross-flow up to re =5 × 106", Journal of Fluid Mechanics, 34(4), pp.625~639 (1968)
- Test of the NACA 0025 and 0035 airfoils in the full scale wind tunnel, "Bullivant, W. K.", NANA, ~, pp.Report No NACA-TR-708 (1941)
- Clapperton, B. L., "Control of circular cylinder flow using distributed passive jets", Journal of Fluid Mechanics, 848, pp.1127~1178 (2018)
- Coutanceau, M., "Experimental determination of the main features of the viscous flow in the wake of a circular cylinder in uniform translation part 1. steady flow", Journal of Fluid Mechanics, 79, pp.231~256 (1977)
- Fackrell, S., "Study of the added mass of cylinders and spheres", Ph.D, pp.2011
- Finaish, F., "A parametric analysis of vortex patterns visualized over airfoils in accelerating flow", Experiments in Fluids, 5, pp.284~288 (1987)
- Garrison, C. J., "Resistance in unsteady flow", M.A.Sc., Department of Engineering Mechanics, pp.1962
- Jones, G. W., "Aerodynamic forces on stationary and oscillating circular cylinder at high reynolds numbers", ASME Symposium on Unsteady Flow, pp.1~30 (1968)
- Forces on cylinders and plates in an oscillating fluid, "Keulegan, G. H.", ~, pp.National Bureau of Standards Report No 4821 (1956)
- 이영빈, "Fundamental studies on free stream acceleration effect on drag force in bluff bodies", Journal of Mechanical Science and Technology, 25(3), pp.695~701 (2011), 대한기계학회
- Lee, Y., "Wind tunnel test of the aerodynamic characteristics around a circular and square cylinders in unsteady accelerated flow", KSAS 2009Spring Conference, pp.78~81 (2009)
- Liu, F., "Numerical study of flow physics and drag of spheres in unsteady motion", 2018 Fluid Dynamics Conference (2018)
- Mason, M. S., "Modulation of vortex induced crosswind forces on a square cylinder during accelerating flow", 20th Australasian Fluid Mechanics Conference Perth (2016)
- Newman, J. N., "Marine Hydrodynamics" (1977), MIT Press
- Rho, J., "Experimental studies on aerodynamic characteristics in unsteady accelerated flow", KSAS 2008 Spring Conference, pp.582~585 (2008)
- Roberson, J. A., "Engineering Fluid Mechanics" (1997)
- Roshko, A., "Experiments on the flow past a circular cylinder at very high reynolds number", Journal of Fluid Mechanics, 10(3), pp.345~356 (1961)
- Sarpkaya, T., "Vortex formation and resistance in unsteady flow", Transactions of the ASME Journal of Applied Mechanics, pp.16~24 (1963)
- Tritton, D. J., "Experiments on the flow past a circular cylinder at low Reynolds numbers", Journal of Fluid Mechanics, 6, pp.547~267 (1959)