پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شماره‌ها | 431 |
| تعداد مقالات | 5,602 |
| تعداد مشاهده مقاله | 7,215,822 |
| تعداد دریافت فایل اصل مقاله | 6,072,372 |
Computational Investigation of the Flow Structure and Drag Characteristics of Spheres in Accelerated Motion | ||
| AUT Journal of Mechanical Engineering | ||
| دوره 8، شماره 3، 2024، صفحه 227-240 اصل مقاله (1.68 M) | ||
| نوع مقاله: Research Article | ||
| شناسه دیجیتال (DOI): 10.22060/ajme.2024.23148.6105 | ||
| نویسندگان | ||
| Hossein Ansarian؛ Mostafa Hadidoolaabi* | ||
| Aerospace Research Institute, Malek Ashtar University of Technology, Tehran, Iran | ||
| چکیده | ||
| The unsteady motion of spheres is important for applications such as falling drops and fuel particle acceleration in nozzles. This study investigates the accelerated spheres’ drag for the acceleration number -0.2 to 0.2 and the Reynolds number 20-170. Unsteady laminar Navier-Stokes equations have been solved using the finite-volume approach, dynamic structured grid, and a second-order semi-implicit pressure-based method. The steady drag coefficient range is 2.7- 0.9 for the specified Reynolds range. For the accelerating sphere, Cd values are larger than the steady-state value (For Re = 20, Cd is 6.1 for a = 125 m/s2 and 3.7 for 32 m/s2). By increasing Re, Cd decreases gradually and then tends to the steady-state value. For deceleration, Cd is smaller than the steady-state value (for Re = 20, Cd is -2.5 for a = -125 m/s2 and 1.3 for -32 m/s2). By increasing Re, Cd increases firstly, then decreases, and finally tends to the steady-state value. The larger the magnitude of acceleration, the farther away the unsteady drag curve is from the steady-state curve. When the sphere is accelerated from rest, the flowfield and the drag tend to the state of steady motion with small Reynolds. For deceleration, they tend to the state of steady motion with a large Reynolds. A new equation is proposed providing a simple accurate method for estimating the spheres’ unsteady drag coefficients. | ||
| کلیدواژه‌ها | ||
| Sphere Drag Coefficient؛ Particle Acceleration؛ Acceleration Number؛ Unsteady Laminar Flow؛ Numerical Simulation | ||
| مراجع | ||
|
[1] B. Jalili, P. Jalili, Numerical analysis of airflow turbulence intensity effect on liquid jet trajectory and breakup in two-phase cross flow, Alexandria Engineering Journal, 68 (2023) 577-585.
[2] G.G. Stokes, On the effect of the internal friction of fluids on the motion of pendulums, Transactions of the Cambridge Philosophical Society, 9(1) (1850), 1-85.
[3] A.B. Basset, On the motion of a sphere in a viscous liquid, Philosophical Transactions of the Royal Society A, 179(1) (1888) 43-63.
[4] H.W. Iversen, R. Balent, A correlating modulus for fluid resistance in accelerated motion, Journal of Applied Physics, 22(3) (1951) 324-328.
[5] S.R. Keim, Fluid resistance to cylinders in accelerated motion, Journal of Hydraulic Engineering, 82(6) (1956) 1-14.
[6] F. Odar, W.S. Hamilton, Forces on a sphere accelerating in a viscous fluid, Journal of Fluid Mechanics, 18(2) (1964) 302-314.
[7] F.W. Roos, W.W. Willmarth, Some experimental results on sphere and disk drag, AIAA Journal, 9(2) (1971) 285-291.
[8] C.T. Crowe, Drag coefficients of inert, burning, or evaporating particles accelerating in gas streams, PhD Thesis, University of Michigan (1961).
[9] E.K. Marchildon, W.H. Gauvin, Effects of acceleration, deceleration and particle shape on single‐particle drag coefficients in still air, Aiche Journal 25(6) (1979) 938-948.
[10] S.K. Karanfilian, T.J. Kotas, Drag on a sphere in unsteady motion in a liquid at rest, Journal of Fluid Mechanics, 87(1) (1978) 85-96.
[11] S.I. Temkin, S.S. Kim, Droplet motion induced by weak shock waves, Journal of Fluid Mechanics, 96(1) (1980) 133-157.
[12] S.I. Temkin, H.K. Mehta, Droplet drag in an accelerating and decelerating flow, Journal of Fluid Mechanics, 116(1), (1982) 297-313.
[13] Y. Tsuji, N. Kato, T. Tanaka, Experiments on the unsteady drag and wake of a sphere at high Reynolds numbers, International Journal of Multiphase Flow, 17(3) (1991) 343-354.
[14] M. Khalloufi, J. Capacelatro, Drag force of compressible flows past random arrays of spheres. International Journal of Multiphase Flow, 165(8) (2023).
[15] E. Loth, J.T. Daspit, M. Jeong, T. Nagata, T. Nonomura, Supersonic and hypersonic drag coefficients for a sphere, AIAA Journal, 59(8) (2021) 3261-3274.
[16] S.D.J.S. Nanayakkara, J. Zhao, S.J. Terrington, M.C. Thomson, K. Hourigan, Effects of surface roughness on the drag coefficient of spheres freely rolling on an inclined plane, Journal of Fluid Mechanics, 984(A13) (2024) 1-41.
[17] H. Kalman, D. Portnikov, New model to predict the velocity and acceleration of accelerating spherical particles, Powder Technology, 415 (2023).
[18] P.K. Billa, T. Josyula, C. Tropea, P.S. Mahapatra, Motion of a rigid sphere entering and penetrating a deep pool, Journal of Fluid Mechanics, (2024).
[19] S. Zhou, G. Zhang, X. Xu, C. He, Experiments on the drag coefficient of a sphere with a variable velocity, Water Supply, 23(5) (2023) 1903-1916.
[20] N. Singh, M. Kroells, C. Li, E. Ching, M. Ihme, C. Hogan, T. Schwartzentruber, A general drag coefficient for flow over a sphere, Journal of Fluid Mechanics, (2020).
[21] S. Davey, C. Atkinson, J. Soria, Measuring unsteady drag of the flow around a sphere based on time series displacement measurements using physics-informed neural networks, Experimental Thermal and Fluid Science, 144 (2023).
[22] L. Unglehrt, M. Manhart, Decomposition of the drag force in steady and oscillatory flow through a hexagonal sphere pack, Journal of Fluid Mechanics, 974 (A32) (2023) 1-36.
[23] T.A. Johnson, V.C. Patel, Flow past a sphere up to a Reynolds number of 300, Journal of Fluid Mechanics, 378 (1999) pp. 19-70.
[24] Q. Qu, M. Hu, H. Guo, P. Liu, R.K. Agarwal, Study of ditching characteristics of transport aircraft by global moving mesh method, Journal of Aircraft, 52(5) (2015) 1550-1558.
[25] S.A. Morsi, A.J. Alexander, An investigation of particle trajectories in two-phase flow systems, Journal of Fluid Mechanics, 55(2) (1972) 193-208.
[26] F.F. Abraham, Functional dependence of drag coefficient of a sphere on Reynolds Number, Physics of Fluids, 13(8) (1970) 2194-2195.
[27] J. Magnaudet, M. Rivero, J. Fabre, Accelerated flows past a rigid sphere or a spherical bubble. I: Steady straining flow, Journal of Fluid Mechanics, 284(1) (1995) 97-135.
[28] F. Liu, P. Liu, Q. Qu, L. Lin, T. Hu, Numerical study of flow physics and drag of spheres in unsteady motion, in: 2018 Fluid Dynamics Conference, 2018, Georgia, USA, 2018. | ||
|
آمار تعداد مشاهده مقاله: 581 تعداد دریافت فایل اصل مقاله: 385 |
||