Volume 21, Issue 1 (January 2021)                   Modares Mechanical Engineering 2021, 21(1): 19-28 | Back to browse issues page

XML Persian Abstract Print


Abstract:   (1945 Views)
The falling and sedimentation of solid particles in liquids occur in many natural and industrial processes such as water and waste water industries, biotechnologies, environmental engineering, marine engineering, etc. This study represents the results of the experimental study of the falling velocity of steel balls in the water channel for different ball diameters (in the range of 8 to 25mm). The tests are done far from the channel walls. Moreover, as a case study, the wall effect on falling velocity of steel ball (i.e. diameter=12mm) is examined. A high-speed camera is used to determine the coordinate of a falling sphere and estimate the ball velocity and drag coefficients. In addition, a numerical method is used to solve the governing equations in comparison with experimental data. Comparing experimental and numerical results for transient and terminal velocities shows the maximum difference of 12 and 4.5% respectively. Experimental drag coefficients have good agreement with other published data. In addition, falling near the wall leads to a negligible effect on velocity but path diversion is observed.
Full-Text [PDF 2075 kb]   (2625 Downloads)    
Article Type: Original Research | Subject: Impact Mechanics
Received: 2021/01/21 | Accepted: 2021/01/19 | Published: 2021/01/19

References
1. Ghasemi A, Pathak A, Raessi M. Computational simulation of the interactions between moving rigid bodies and incompressible two-fluid flows. Computers & Fluids. 2014;94:1-13.
2. Cronin K, Çatak M, Tellez-Medina D, Cregan V, O’Brien S. Modelling of particle motion in an internal re-circulatory fluidized bed. Chemical Engineering Journal. 2010;164(2-3):393-402.
3. He C, Scott E, Rochfort Q. Enhancing sedimentation by improving flow conditions using parallel retrofit baffles. Journal of environmental management. 2015;160:1-6.
4. Vigolo D, Griffiths IM, Radl S, Stone HA. An experimental and theoretical investigation of particle–wall impacts in a T-junction. Journal of Fluid Mechanics. 2013;727:236-55
5. Zhu C, Liu G, Ye J, Xu H. Experimental investigation of non-stationary motion of single small spherical particles in an upward flow with different velocities. Powder Technology. 2015;273:111-7.
6. Fedosov DA, Dao M, Karniadakis GE, Suresh S. Computational biorheology of human blood flow in health and disease. Annals of biomedical engineering. 2014;42(2):368-87.
7. Djukic T. Particle Dynamics and Design of Nano-drug Delivery Systems. InComputational Medicine in Data Mining and Modeling 2013 (pp. 309-347). Springer, New York, NY.
8. Florio LA. Direct particle motion and interaction modeling method applied to simulate propellant burn. Applied Mathematical Modelling. 2013;37(8):5606-26.
9. Van Cauwenberghe L, Devriese L, Galgani F, Robbens J, Janssen CR. Microplastics in sediments: a review of techniques, occurrence and effects. Marine environmental research. 2015;111:5-17.
10. Powers MC. A new roundness scale for sedimentary particles. Journal of Sedimentary Research. 1953;23(2):117-9.
11. Choi C, Yoon HS, Ha MY. Flow and motion characteristics of a freely falling square particle in a channel. Computers & Fluids. 2013;79:1-2.
12. Mehrabian S, Acosta E, Bussmann M. Oil-particle separation in a falling sphere configuration: Effect of viscosity ratio & interfacial tension. International Journal of Multiphase Flow. 2018;98:120-7.
13. Mehri A, Akbarzadeh P. Hydrodynamic characteristics of heated/non-heated and grooved/un-grooved spheres during free-surface water entry. Journal of Fluids and Structures. 2020;97:103100.
14. Chu CR, Wu TR, Tu YF, Hu SK, Chiu CL. Interaction of two free-falling spheres in water. Physics of Fluids. 2020;32(3):033304
15. Hazzab A, Terfous A, Ghenaim A. Measurement and modeling of the settling velocity of isometric particles. Powder Technology. 2008;184(1):105-13

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.