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Abstract

The main topic of this study is the experimental measurement and mathematical modelling of global gas hold-up and bubble size distribution in an aerated stirred vessel using the population balance method. The air-water system consisted of a mixing tank of diameter T = 0.29 m, which was equipped with a six-bladed Rushton turbine. Calculations were performed with CFD software CFX 14.5. Turbulent quantities were predicted using the standard k-ε turbulence model. Coalescence and breakup of bubbles were modelled using the homogeneous MUSIG method with 24 bubble size groups. To achieve a better prediction of the turbulent quantities, simulations were performed with much finer meshes than those that have been adopted so far for bubble size distribution modelling. Several different drag coefficient correlations were implemented in the solver, and their influence on the results was studied. Turbulent drag correction to reduce the bubble slip velocity proved to be essential to achieve agreement of the simulated gas distribution with experiments. To model the disintegration of bubbles, the widely adopted breakup model by Luo & Svendsen was used. However, its applicability was questioned.

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Authors and Affiliations

Zbyněk Kálal
Milan Jahoda
Ivan Fořt
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Abstract

The converging-diverging structure is introduced to extend the lower limit of measurement of vortex flowmeters. As a compact device, the converging-diverging vortex flowmeter is proposed and designed, and its performance is studied experimentally. It is found that, first of all, an up to 51% extension of the lower measurement limit can be realized through the converging-diverging structure, compared with conventional vortex flowmeters; second, the converging-diverging vortex flowmeter with a trapezoidal bluff body has a larger Strouhal number and smaller pressure loss. The results suggest that the converging-diverging vortex flowmeter provides an alternative device especially suitable for the measurement of low-velocity fluids.

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Authors and Affiliations

Zhiqiang Sun
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Abstract

The present study investigates the 2D numerical analogies to the changes of the droplet shapes during the freefall for a wide range of droplet sizes through the stagnation air. The freefall velocity, shape change due to frictional force during free-fall is studied for different considered cases. With the elapse of time, a droplet with a larger initial diameter is changing its original shape more compared to droplets with a smaller diameter. In addition, the spreading of the droplet during the freefall seems more rapid for the larger-diameter droplet. When a droplet with an initial diameter of 15 mm starts to fall with gravitational force, the diameter ratio is decreasing for droplets with higher density and surface tension while droplets having lower density and surface tension show a diameter ratio greater than one. The spreading and splashing of the droplet on a solid surface and liquid storage at the time of impact are much influenced by the freefall memories of the droplet during the freefall from a certain height. These freefall memories are influenced by the fluid properties, drag force, and the freefall height. However, these freefall memories eventually regulate the deformation of the droplet during the freefall.
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Bibliography

[1] X. Cao, Y. Ye, Q. Tang, E. Chen, Z. Jiang, J. Pan, and T. Guo. Numerical analysis of droplets from multinozzle inkjet printing. The Journal of Physical Chemistry Letters, 11(19):8442–8450, 2020. doi: 10.1021/acs.jpclett.0c02250.
[2] H. Wijshoff. Drop dynamics in the inkjet printing process. Current Opinion in Colloid & Interface Science, 36:20–27, 2018. doi: 10.1016/j.cocis.2017.11.004.
[3] W. Zhou, D. Loney, A.G. Fedorov, F.L. Degertekin, and D.W. Rosen. Shape evolution of droplet impingement dynamics in ink-jet manufacturing. Proceedings for the 2011 International Solid Freeform Fabrication Symposium, pages 309–325, Austin, USA, 2011. doi: 10.26153/tsw/15297.
[4] L. Mouzai and M. Bouhadef. Water drop erosivity: Effects on soil splash. Journal of Hydraulic Research, 41(1):61–68, 2003. doi: 10.1080/00221680309499929.
[5] M. Hajigholizadeh, A.M. Melesse, and H.R. Fuentes. Raindrop-induced erosion and sediment transport modelling in shallow waters: A review. Journal of Soil and Water Science, 1(1):15–25, 2018. doi: 10.36959/624/427.
[6] P.C. Ekern. Raindrop impact as the force initiating soil erosion. Soil Science Society of America Journal, 15(C):7–10, 1951. doi: 10.2136/sssaj1951.036159950015000C0002x.
[7] R. Andrade, O. Skurtys, and F. Osorio. Drop impact behavior on food using spray coating: Fundamentals and applications. Food Research International, 54(1):397–405, 2013. doi: 10.1016/j.foodres.2013.07.042.
[8] M. Toivakka. Numerical investigation of droplet impact spreading in spray coating of paper. Proceedings of the 2003 Spring Advanced Coating Fundamentals Symposium, Atlanta, USA, 2003.
[9] A. Prasad and H. Henein. Droplet cooling in atomization sprays. Journal of Materials Science, 43(17):5930–5941, 2008. doi: 10.1007/s10853-008-2860-2.
[10] W. Jia and H.-H. Qiu. Experimental investigation of droplet dynamics and heat transfer in spray cooling. Experimental Thermal and Fluid Science, 27(7):829–838, 2003. doi: 10.1016/S0894-1777(03)00015-3.
[11] G. Duursma, K. Sefiane, and A. Kennedy. Experimental studies of nanofluid droplets in spray cooling. Heat Transfer Engineering, 30(13):1108–1120, 2009. doi: 10.1080/01457630902922467.
[12] W.-C. Qin, B.-J. Qiu, X.-Y. Xue, C. Chen, Z.-F. Xu, and Q.-Q. Zhou. Droplet deposition and control effect of insecticides sprayed with an unmanned aerial vehicle against plant hoppers. Crop Protection, 85:79–88, 2016. doi: 10.1016/j.cropro.2016.03.018.
[13] S. Chen, Y. Lan, Z. Zhou, F. Ouyang, G. Wang, X. Huang, X. Deng, and S. Cheng. Effect of droplet size parameters on droplet deposition and drift of aerial spraying by using plant protection UAV. Agronomy, 10(2):195, 2020. doi: 10.3390/agronomy10020195.
[14] D.T. Sheppard. Spray Characteristics of Fire Sprinklers. Ph.D. Thesis, Northwestern University, Evanston, USA, June 2002.
[15] H. Liu, C.Wang, I.M. De Cachinho Cordeiro, A.C.Y. Yuen, Q. Chen, Q.N. Chan, S. Kook, and G.H. Yeoh. Critical assessment on operating water droplet sizes for fire sprinkler and water mist systems. Journal of Building Engineering, 28:100999, 2020. doi: 10.1016/j.jobe.2019.100999.
[16] D.C. Blanchard. The behavior of water drops at terminal velocity in air. Eos, Transactions American Geophysical Union, 31(6):836–842, 1950. doi: 10.1029/TR031i006p00836.
[17] H.R. Pruppacher and K.V. Beard. A wind tunnel investigation of the internal circulation and shape of water drops falling at terminal velocity in air. Quarterly Journal of the Royal Meteorological Society, 96(408):247–256, 1970. doi: 10.1002/qj.49709640807.
[18] H.R. Pruppacher and R.L. Pitter. A semi-empirical determination of the shape of cloud and rain drops. Journal of the Atmospheric Sciences, 28(1):86–94, 1971. doi: 10.1175/1520-0469(1971)0280086:ASEDOT>2.0.CO;2.
[19] K.V. Beard and C. Chuang. A new model for the equilibrium shape of raindrops. Journal of the Atmospheric Sciences, 44(11):1509–1524, Jun. 1987. doi: 10.1175/1520-0469(1987)0441509:ANMFTE>2.0.CO;2.
[20] É.Reyssat, F. Chevy, A.L. Biance, L. Petitjean, and D. Quéré. Shape and instability of free-falling liquid globules. Europhysics Letters, 80(3):34005, 2007. doi: 10.1209/0295-5075/80/34005.
[21] R. Clift, J.R. Grace, and M.E. Weber. Bubbles, Drops and Particles. Academic Press, 1978.
[22] S.-C. Yao and V.E. Schrock. Heat and mass transfer from freely falling drops. Journal of Heat Transfer, 98(1):120–126, 1976. doi: 10.1115/1.3450453.
[23] T.J. Horton, T.R. Fritsch, and R.C. Kintner. Experimental determination of circulation velocities inside drops. The Canadian Journal of Chemical Engineering, 43(3):143–146, 1965. doi: 10.1002/cjce.5450430309.
[24] R.H. Magarvey and B.W. Taylor. Free fall breakup of large drops. Journal of Applied Physics, 27(10):1129–1135, 1956. doi: 10.1063/1.1722216.
[25] M.N. Chowdhury, F.Y. Testik, M.C. Hornack, and A.A. Khan. Free fall of water drops in laboratory rainfall simulations. Atmospheric Research, 168:158–168, 2016. doi: 10.1016/j.atmosres.2015.08.024.
[26] M. Abdelouahab and R. Gatignol. Study of falling water drop in stagnant air. European Journal of Mechanics - B/Fluids, 60:82–89, 2016. doi: 10.1016/j.euromechflu.2016.07.007.
[27] J.H. van Boxel. Numerical model for the fall speed of raindrops in a rainfall simulator. I.C.E Special Report, 1998/1, 77–85,
[28] A.K. Kamra and D.V Ahire. Wind-tunnel studies of the shape of charged and uncharged water drops in the absence or presence of an electric field. Atmospheric Research, 23(2):117–134, 1989. doi: 10.1016/0169-8095(89)90003-3.
[29] M. Thurai and V.N. Bringi. Drop axis ratios from a 2D video disdrometer. Journal of Atmospheric and Oceanic Technology, 22(7):966–978, 2005. doi: 10.1175/JTECH1767.1.
[30] C. Josserand and S.T. Thoroddsen. Drop impact on a solid surface. Annual Review of Fluid Mechanics, 48:365–391, 2016. doi: 10.1146/annurev-fluid-122414-034401.
[31] J. Eggers, M.A. Fontelos, C. Josserand, and S. Zaleski. Drop dynamics after impact on a solid wall: Theory and simulations. Physics of Fluids, 22(6):062101, 2010. doi: 10.1063/1.3432498.
[32] S. Chandra and C.T. Avedisian. On the collision of a droplet with a solid surface. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 432(1884):13–41, 1991. doi: 10.1098/rspa.1991.0002.
[33] O.G. Engel. Waterdrop collisions with solid surfaces. Journal of Research of the National Bureau of Standards, 54(5):281–298, 1955. doi: 10.6028/jres.054.033.
[34] I.V. Roisman, R. Rioboo, and C. Tropea. Normal impact of a liquid drop on a dry surface: model for spreading and receding. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 458(2022):1411–1430, 2002. doi: 10.1098/rspa.2001.0923.
[35] Y. Renardy, S. Popinet, L. Duchemin, M. Renardy, S. Zaleski, C. Josserand, M.A. Drumright-Carke, D. Richard, C. Clanet, and D. Quéré. Pyramidal and toroidal water drops after impact on a solid surface. Journal of Fluid Mechanics, 484:69–83, 2003. doi: 10.1017/S0022112003004142.
[36] D. Bartolo, F. Bouamrirene, É. Verneuil, A. Buguin, P. Silberzan, and S. Moulinet. Bouncing or sticky droplets: Impalement transitions on superhydrophobic micropatterned surfaces. Europhysics Letters, 74(2):299–305, 2006. doi: 10.1209/epl/i2005-10522-3.
[37] D. Bartolo, C. Josserand, and D. Bonn. Singular jets and bubbles in drop impact. Physical Review Letters, 96:124501, 2006. doi: 10.1103/PhysRevLett.96.124501.
[38] C. Clanet, C. Béguin, D. Richard, and D. Quéré. Maximal deformation of an impacting drop. Journal of Fluid Mechanics, 517:199–208, 2004. doi: 10.1017/S0022112004000904.
[39] L.H.J. Wachters, L. Smulders, J.R. Vermeulen, and H.C. Kleiweg. The heat transfer from a hot wall to impinging mist droplets in the spheroidal state. Chemical Engineering Science, 21(12):1047–1056, 1966. doi: 10.1016/0009-2509(66)85042-X.
[40] C.O. Pedersen. An experimental study of the dynamic behavior and heat transfer characteristics of water droplets impinging upon a heated surface. International Journal of Heat and Mass Transfer, 13(2):369–381, 1970. doi: 10.1016/0017-9310(70)90113-4.
[41] M.A. Styricovich, Y.V. Baryshev, G.V. Tsiklauri and M E. Grigorieva. The mechanism of heat and mass transfer between a water drop and a heated surface. Proceedings of the Sixth International Heat Transfer Conference, Vol. 1, pages 239-243, Toronto, Canada, August 7-11, 1978.
[42] P. Savic and G.T. Boult. The fluid flow associated with the impact of liquid drops with solid surfaces. Proceedings of Heat Transfer Fluid Mechanics Institution, 43-84, 1957.
[43] S.E. Hinkle. Water drop kinetic energy and momentum measurement considerations. Applied Engineering in Agriculture, 5(3):386–391, 1989. doi: 10.13031/2013.26532.
[44] C.D. Stow and R.D. Stainer. The physical products of a splashing water drop. Journal of Meteorological Society of Japan, 55(5):518–532, 1977.
[45] Z. Levin and P.V. Hobbs. Splashing of water drops on solid and wetted surfaces, Hydrodynamics and charge separation. Philosophical Transactions of the Royal Society A Mathematical, Physical and Engineering Sciences, 269(1200):555–585, 1971. doi: 10.1098/rsta.1971.0052.
[46] C.D. Stow, M.G. Hadfield. An experimental investigation of fluid flow resulting from the impact of a water drop with an unyielding dry surface. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 37(1755):419–441, 1981. doi: 10.1098/rspa.1981.0002.
[47] C. Mundo, M. Sommerfeld, and C. Tropea. Droplet-wall collisions: Experimental studies of the deformation and breakup process. I nternational Journal of Multiphase Flow, 21(2):151–173, 1995. doi: 10.1016/0301-9322(94)00069-V.
[48] M. Bussmann, S. Chandra, and J. Mostaghimi. Modeling the splash of a droplet impacting a solid surface. Physics of Fluids, 12(12):3121–3132, 2000. doi: 10.1063/1.1321258.
[49] L. Xu, W.W. Zhang, and S.R. Nagel. Drop splashing on a dry smooth surface. Physical Review Letters, 94(18):184505, 2005. doi: 10.1103/PhysRevLett.94.184505.
[50] B.T. Helenbrook and C.F. Edwards. Quasi-steady deformation and drag of uncontaminated liquid drops. International Journal of Multiphase Flow, 28(10):1631–1657, 2002. doi: 10.1016/S0301-9322(02)00073-3.
[51] J.Q. Feng. A deformable liquid drop falling through a quiescent gas at terminal velocity. Journal of Fluid Mechanics, 658:438–462, 2010. doi: 10.1017/S0022112010001825.
[52] J.Q. Feng and K.V. Beard. Raindrop shape determined by computing steady axisymmetric solutions for Navier-Stokes equations. Atmospheric Research, 101(1–2):480–491, 2011. doi: 10.1016/j.atmosres.2011.04.012.
[53] J. Han and G. Tryggvason. Secondary breakup of axisymmetric liquid drops. I. Acceleration by a constant body force. Physics of Fluids, 11(12):3650–3667, 1999. doi: 10.1063/1.870229.
[54] J. Han and G. Tryggvason. Secondary breakup of a axisymmetric liquid drops. II. Impulsive acceleration. Physics of Fluids, 13(6):1554–1565, 2001. doi: 10.1063/1.1370389.
[55] P. Khare and V. Yang. Breakup of non-Newtonian liquid droplets. 44th AIAA Fluid Dynamics Conference, Atlanta, USA, 16-20 June 2014. doi: 10.2514/6.2014-2919.
[56] M. Sussman and E.G. Puckett. A Coupled level set and volume-of-fluid method for computing 3D and axisymmetric incompressible two-phase flows. Journal of Computational Physics, 162(2):301–337, 2000. doi: 10.1006/jcph.2000.6537.
[57] R. Scardovelli and S. Zaleski. Direct numerical simulation of free-surface and interfacial flow. Annual Review of Fluid Mechanics, 31:567–603, 1999. doi: 10.1146/annurev.fluid.31.1.567.
[58] S. Shin and D. Juric. Simulation of droplet impact on a solid surface using the level contour reconstruction method. Journal of Mechanical Science and Technology, 23:2434–2443, 2009. doi: 10.1007/s12206-009-0621-z.
[59] M. García Pérez and E. Vakkilainen. A comparison of turbulence models and two and three dimensional meshes for unsteady CFD ash deposition tools. Fuel, 237:806–811, 2019. doi: 10.1016/j.fuel.2018.10.066.
[60] M. Mezhericher, A. Levy, and I. Borde. Modeling of droplet drying in spray chambers using 2D and 3D computational fluid dynamics. Drying Technology, 27(3):359–370, 2009. doi: 10.1080/07373930802682940.
[61] S. Afkhami and M. Bussmann. Height functions for applying contact angles to 2D VOF simulations. International Journal for Numerical Methods in Fluids, 57(4):453-472, 2008. doi: 10.1002/fld.1651.
[62] J. Zheng, J. Wang, Y. Yu, and T. Chen. Hydrodynamics of droplet impingement on a thin horizontal wire. Mathematical Problems in Engineering, 2018:9818494, 2018. doi: 10.1155/2018/9818494.
[63] J. Thalackottore Jose and J.F. Dunne. Numerical simulation of single-droplet dynamics, vaporization, and heat transfer from impingement onto static and vibrating surfaces. Fluids, 5(4):188, 2020. doi: 10.3390/fluids5040188.
[64] H. Liu. Science and Engineering of Droplets: Fundamentals and Applications. Noyes Publications, USA, 1999.
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Authors and Affiliations

Abid Hasan Rafi
1
ORCID: ORCID
Mohammad Rejaul Haque
1
ORCID: ORCID
Dewan Hasan Ahmed
1
ORCID: ORCID

  1. Department of Mechanical and Production Engineering, Ahsanullah University of Science and Technology, Dhaka, Bangladesh
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Abstract

The main goal of today’s car designers is to minimize fuel consumption in all possible ways at the same time maintaining the vehicle’s performance as usual. The goal of this work is to study the effect of adding a vortex generator (VG) on the aerodynamics of the vehicle and fuel economy. Both theoretical and experimental works were carried out and the outcomes of the numerical simulations are contrasted with those of the experimental results. A utility vehicle model with a scale ratio of 1:15 was used as a test model. Experimental research has been done on the fluctuation of the coefficient of pressure, dynamic pressure, and coefficients of lift and drag with and without VG on the roof of a utility vehicle. The delta-shaped VG was put to the test both numerically and experimentally. At a velocity of 2.42 m/s, it is observed that the addition of VG can raise the pressure coefficient by about 17%. When compared to the vehicle model without vortex generators, the velocity profile of the ccomputational fluid dynamics analysis shows that at the back end of the vehicle, the wake has been minimized with VG.
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Authors and Affiliations

Ramesh Kumar Chidambaram
1
Rajesh Kanna
2
Poomanandan Gopal
3
Senthil Kumar Arumugam
4

  1. Vellore Institute of Technology, Automotive Research Centre, Vellore – 632014, India
  2. Vellore Institute of Technology, CO2 Research and Green Technologies Center, Vellore – 632014, India
  3. Anna University, Department of Automobile Engineering, BIT Campus, Tiruchirappalli, 620024, India
  4. VIT Bhopal University, Bhopal, 466114, India
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Abstract

This paper presents new results for the dynamic behaviour of fluid around a rotating turbulator in a channel. The turbulator has a propeller form which is placed inside a flat channel. The research was carried out using 3D numerical simulation. The rationale of the experiment was as follows: we put a propeller-turbulator inside a flat channel, and then we insert a water flow inside the channel. The turbulator rotates at a constant and uniform speed. The main points studied here are the effect of the presence of turbulator and its rotational direction on the flow behaviour behind the turbulator. The results showed that the behaviour of flow behind the turbulator is mainly related to the direction of turbulator rotating. Also, the studied parameters affect coefficients of drag force and power number. For example, when the turbulator rotates in the positive direction, the drag coefficient decreases in terms of rotational speed of the turbulator, while the drag coefficient increases in terms of rotational speed when the turbulator rotates in the negative direction.
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Authors and Affiliations

Elhadi Zoubai
1
Houssem Laidoudi
1
Ismail Tlanbout
1
Oluwole Daniel Makinde
2

  1. University of Science and Technology of Oran Mohamed-Boudiaf, Faculty of Mechanical Engineering, Laboratory of Sciences and Marine Engineering, BP 1505, El-Menaouer, Oran, 31000, Algeria
  2. Stellenbosch University, Faculty of Military Science, Private Bag X2, Saldanha 7395, South Africa
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Abstract

The placement of the battery box can have a massive impact on the aerodynamics of an electric vehicle. Although favourable from the viewpoint of vehicle dynamics, an underbody battery box may impair the vehicle aerodynamics. This study aims to quantify the effect of an underbody battery box on the drag force acting on an electric vehicle. Four different variants of the vehicle (original variant, lifted suspension, lifted suspension with an underbody battery box) are investigated by means of computational fluid dynamics. The underbody battery box was found to induce flow separation, resulting in a massive increase in drag force. As a solution, a battery box fairing was designed and tested. The fairing significantly reduced the increase in drag. The results of this study could contribute to the design of more stable and aerodynamically efficient electric vehicles.
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Bibliography

[1] Where the Energy Goes: Electric Cars. US DOE, US EPA. https://www.fueleconomy.gov/feg/atv-ev.shtml (accessed 20 March 2021).
[2] Simmonds N., Pitman J., Tsoutsanis P., Jenkins K., Gaylard A., Jansen W.: Complete body aerodynamic study of three vehicles. SAE Tech. Pap. (2017), 2017-01-1529.
[3] Ahmed S.R. Ramm G., Faltin G.: Some salient features of the time-averaged ground vehicle wake. SAE Transactions 93(1984), 2, 840222–840402, 473–503.
[4] Buchheim R., Deutenbach K.-R., Lückoff H.-J.: Necessity and premises for reducing the aerodynamic drag of future passenger cars. SAE Transactions 90(1981), 1, 810010–810234, 758–771.
[5] Cooper K.R., Bertenyi T., Dutil G. Syms, J. Sovran G.: The aerodynamic performance of automotive underbody diffusers. SAE Tech. Pap. (1998), 980030, 150–179.
[6] Potthoff J.: The aerodynamic layout of UNICAR research vehicle. In: Proc. Int. Symp. on Vehicle Aerodynamics, Wolfsburg, 1982.
[7] Katz J.: Race Car Aerodynamics: Designing for Speed. Bentley, 1995.
[8] Hucho W.: Aerodynamics of Road Vehicles. From Fluid Mechanics to Vehicle Engineering. Butterworth-Heinemann, 1987.
[9] Katz J.: Automotive Aerodynamics. Wiley, 2016. [10] Shinde, Gopal, Aniruddha Joshi, Kishor Nikam.: Numerical investigations of the drivAer car model using opensource CFD solver OpenFOAM. Tata Consult. Serv., Pune, 2013.
[11] DrivAer Model. https://www.mw.tum.de/en/aer/research-groups/automotive/drivaer/ (accessed 15 Apr. 2021).
[12] Jakirlic S., Kutej L., Hanssmann D., Basara B., Tropea C.: Eddy-resolving simulations of the notchback ‘DrivAer’ model: Influence of underbody geometry and wheels rotation on aerodynamic behaviour. SAE Tech. Pap. (2016), 2016-01-1602.
[13] abois M., Lakehal D.: Very-large eddy simulation (V-LES) of the flow across a tube bundle. Nucl. Eng. Des. 241(2011), 6, 2075–2085.
[14] Heft A.: Aerodynamic investigation of the cooling requirements of electric vehicles. PhD thesis, Technische Universität München, Munich 2014.
[15] Heft A.I., Indinger T. Adams N.A.: Introduction of a new realistic generic car model for aerodynamic investigations. SAE Tech. Pap. (2012), 2012-01-0168.
[16] Janssen L.J., Hucho W.H.: The effect of various parameters on the aerodynamic drag of passenger cars. In: Advances in Road Vehicle Aerodynamics (H.S. Stevens, Ed.), 1973. 223-254.
[17] Wright P.G.: The influence of aerodynamics on the design of Formula One racing cars. Int. J. Vehicle Des. 3(1982), 4, 383–397.
[18] Eagle Two. http://lodzsolarteam.p.lodz.pl/index.php/eagle-two/ (accessed 3 May 2021).
[19] Lanfrit M.: Best Practice Guidelines for Handling Automotive External Aerodynamics with Fluent. Fluent Deutschland, Darmstadt 2005.
[20] Ansys Fluent Mosaic – new mesh generation technology incorporating hexahedral and polyhedral elements. Symkom, Łódz 2019. https://symkom.pl/ansys-fluent-mosaic/ (accessed 16 March 2021).
[21] Ansys: Ansys Fluent User’s Guide. 2013.
[22] Schlichting H.: Boundary-Layer Theory. McGraw Hill, 1979.
[23] Miao L., Mack S., Indinger T.: Experimental and numerical investigation of automotive aerodynamics using DrivAer model. In: Proc. ASME 2015 Int. Design Engineering Technical Conferences and Computers and Information in Engineering Conf., Boston, Aug. 2–5, 2015. V003T01A039. ASME.
[24] Heft A.I., Indinger T., Adams N.A.: Experimental and numerical investigation of the DrivAer model. In: Proc. Fluids Engineering Division Summer Meeting, Rio Grande, July 8–12, 2012, FEDSM2012-72272, 41–51. ASME.
[25] Heft A.I., Indinger T., Adams N.: Investigation of unsteady flow structures in the wake of a realistic generic car model. In: Proc. 29th AIAA Applied Aerodynamics Conf., June 2011, 3669.
[26] Ashton N., West A., Lardeau S., Revell A.: Assessment of RANS and DES methods for realistic automotive models. Comput. Fluids 128(2016), 1–15.
[27] Guilmineau E., Deng G., Leroyer A., Queutey P., Wackers J., Visonneau M. (2016, June): Assessment of RANS and DES methods for the Ahmed body. In: Proc. ECCOMAS Cong. 2016 VII Eur. Cong. on Computational Methods in Applied Sciences and Engineering (M. Papadrakakis, V. Papadopoulos, G. Stefanou, V. Plevris, Eds.), Crete Island, 5-10 June 2016.
[28] Menter F.R.: Zonal two equation k − ! turbulence models for aerodynamic flows. In: Proc. 23rd Fluid Dynamics, Plasmadynamics, and Lasers Conf., Orlando, 6–9 July 1993, AIAA-93-2906.
[29] Ansys Inc.: Ansys Fluent 12.0 Theory Guide, 2009.
[30] Menter F.R.: Two-equation eddy-viscosity turbulence models for engineering applications. AIAA J 32(1994), 8, 1598–1605.
[31] Sobczak K.: Numerical investigations of an influence of the aspect ratio on the Savonius rotor performance. J. Phys. Conf. Ser. 1101(2018), 1, 012034.
[32] Huang P.G., Bardina J., Coakley T.: Turbulence modeling validation, testing, and development. NASA Tech. Memorand. (1997), 110446, 147.
[33] Pawłucki M., Krys M.: CFD for Engineers. Helion, Gliwice 2020.
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Authors and Affiliations

Jakub Bobrowski
1
Krzysztof Sobczak
1

  1. Institute of Turbomachinery, Lodz University of Technology, 217/221 Wolczanska, 93-005 Łódz Poland
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Abstract

Sintered ore used as blast furnace burden materials is produced by mixing iron ore, coke, and limestone, then burning the coke and sintering the iron ore with the combustion heat. Among the coke charged, A particle size of 0.25 mm or less has an insignificant effect as a heat source and adhere to the surface of other materials to inhibit the reaction between oxygen and raw materials, thereby decreasing the quality of sintered ore. Therefore, to increase combustion efficiency, it is necessary to reduce the ratio of coke breeze in the charged coke.
In this study, theoretical calculation, experiment and simulation were conducted to investigate the possibility of size classification by drag force in the process of dropping coke after being transported through a belt conveyor. The height of belt conveyor was at 1m, and velocity of the belt was 1.5, 2.3, and 2.6 m/s, which were considered as experimental variables. After falling, the distribution of coke particle size according to the horizontal travel distance was confirmed, and a fall trajectory prediction formula model was created through the drag model of polydisperse system and compared with the experimental and analysis results.
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Authors and Affiliations

Ji-A Lee
1
ORCID: ORCID
Bong-Min Jin
1
ORCID: ORCID
Jeong-Whan Han
1
ORCID: ORCID

  1. Inha University, Department of Materials Science and Engineering, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
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Abstract

This paper concerns the analytical investigation of the axisymmetric and steady flow of incompressible couple stress fluid through a rigid sphere embedded in a porous medium. In the porous region, the flow field is governed by Brinkman's equation. Here we consider uniform flow at a distance from the sphere. The boundary conditions applied on the surface of the sphere are the slip condition and zero couple stress. Analytical solution of the problem in the terms of stream function is presented by modified Bessel functions. The drag experienced by an incompressible couple stress fluid on the sphere within the porous medium is calculated. The effects of the slip parameter, the couple stress parameter, and permeability on the drag are represented graphically. Special cases of viscous flow through a sphere are obtained and the results are compared with earlier published results.
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Bibliography

[1] J. Bear. Dynamics of fluids in porous media. Courier Corporation, 2013.
[2] H.C. Brinkman. A calculation of the viscous force exerted by a flowing fluid on a dense swarm of particles. Flow, Turbulence and Combustion, 1(1):27–34, 1949. doi: 10.1007/bf02120313.
[3] R.H. Davis and H.A. Stone. Flow through beds of porous particles. Chemical Engineering Science, 48(23):3993–4005, 1993. doi: 10.1016/0009-2509(93)80378-4.
[4] B. Barman. Flow of a Newtonian fluid past an impervious sphere embedded in a porous medium. Indian Journal of Pure and Applied Mathematics, 27:1249–1256, 1996.
[5] I. Pop and D.B. Ingham. Flow past a sphere embedded in a porous medium based on the Brinkman model. International Communications in Heat and Mass Transfer, 23(6):865–874, 1996. doi: 10.1016/0735-1933(96)00069-3.
[6] D. Srinivasacharya and J.V. Ramana Murthy. Flow past an axisymmetric body embedded in a saturated porous medium. Comptes Rendus Mécanique, 330(6):417–423, 2002. doi: 10.1016/s1631-0721(02)01478-x.
[7] T. Grosan, A. Postelnicu, and I. Pop. Brinkman flowof a viscous fluid through a spherical porous medium embedded in another porous medium. Transport in Porous Media, 81(1):89–103, 2010. doi: 10.1007/s11242-009-9389-y.
[8] S. Deo and B.R. Gupta. Drag on a porous sphere embedded in another porous medium. Journal of Porous Media, 13(11):1009–1016, 2010. doi: 10.1615/JPorMedia.v13.i11.70.
[9] N.E. Leontev. Flow past a cylinder and a sphere in a porous medium within the framework of the Brinkman equation with the Navier boundary condition. Fluid Dynamics, 49(2):232–237, 2014. doi: 10.1134/S0015462814020112.
[10] S. El-Sapa. Effect of permeability of Brinkman flow on thermophoresis of a particle in a spherical cavity. European Journal of Mechanics-B/Fluids, 79:315–323, 2020. doi: 10.1016/j.euromechflu.2019.09.017.
[11] M.S. Faltas, H.H. Sherief, A.A. Allam, and B.A. Ahmed. Mobilities of a spherical particle straddling the interface of a semi-infinite Brinkman flow. Journal of Fluids Engineering, 143(7):071402, 2021. doi: 10.1115/1.4049931.
[12] M. Krishna Prasad and D. Srinivasacharya. Micropolar fluid flow through a cylinder and a sphere embedded in a porous medium. International Journal of Fluid Mechanics Research, 44(3):229–240, 2017. doi: 10.1615/InterJFluidMechRes.2017015283.
[13] B.R. Jaiswal. A non-Newtonian liquid sphere embedded in a polar fluid saturated porous medium: Stokes flow. Applied Mathematics and Computation, 316:488–503, 2018. doi: 10.1016/j.amc.2017.08.009.
[14] K. Ramalakshmi and P. Shukla. Drag on a fluid sphere embedded in a porous medium with solid core. International Journal of Fluid Mechanics Research, 46(3):219–228, 2019. doi: 10.1615/InterJFluidMechRes.2018025197.
[15] K.P. Madasu and T. Bucha. Influence of mhd on micropolar fluid flow past a sphere implanted in porous media. Indian Journal of Physics, 95(6):1175–1183, 2021. doi: 10.1007/s12648-020-01759-7.
[16] V.K. Stokes. Couple stresses in fluids. In Theories of Fluids with Microstructure, pages 34–80. Springer, 1966. doi: 10.1007/978-3-642-82351-0_4.
[17] V.K. Stokes. Theories of Fluids with Microstructure: An Introduction. Springer Science & Business Media, 2012. doi: 10.1007/978-3-642-82351-0.
[18] D. Pal, N. Rudraiah, and R. Devanathan. A couple stress model of blood flow in the microcirculation. Bulletin of Mathematical Biology, 50(4):329–344, 1988. doi: 10.1007/BF02459703.
[19] N.A. Khan, A. Mahmood, and A. Ara. Approximate solution of couple stress fluid with expanding or contracting porous channel. Engineering Computations, 30(3):399–408, 2013. doi: 10.1108/02644401311314358.
[20] D. Srinivasacharya and K. Kaladhar. Mixed convection flowof couple stress fluid in a non-Darcy porous medium with Soret and Dufour effects. Journal of Applied Science and Engineering, 15(4):415–422, 2012.
[21] M. Devakar, D. Sreenivasu, and B. Shankar. Analytical solutions of couple stress fluid flows with slip boundary conditions. Alexandria Engineering Journal, 53(3):723–730, 2014. doi: 10.1016/j.aej.2014.06.005.
[22] D. Srinivasacharya, N. Srinivasacharyulu, and O. Odelu. Flow of couple stress fluid between two parallel porous plates. International Journal of Applied Mathematics, 41(2).
[23] E.A. Ashmawy. Drag on a slip spherical particle moving in a couple stress fluid. Alexandria Engineering Journal, 55(2):1159–1164, 2016. doi: 10.1016/j.aej.2016.03.032.
[24] P. Aparna, P. Padmaja, N. Pothanna, and J.V. Ramana Murthy. Couple stress fluid flow due to slow steady oscillations of a permeable sphere. Nonlinear Engineering, 9(1):352–360, 2020. doi: 10.1515/nleng-2020-0021.
[25] S.O. Adesanya, S.O. Kareem, J.A. Falade, and S.A. Arekete. Entropy generation analysis for a reactive couple stress fluid flow through a channel saturated with porous material. Energy, 93:1239–1245, 2015. doi: 10.1016/j.energy.2015.09.115.
[26] A.R. Hassan. The entropy generation analysis of a reactive hydromagnetic couple stress fluid flow through a saturated porous channel. Applied Mathematics and Computation, 369:124843, 2020. doi: 10.1016/j.amc.2019.124843.
[27] S.I.Abdelsalam, J.X.Velasco-Hernández, and A.Z. Zaher. Electro-magnetically modulated selfpropulsion of swimming sperms via cervical canal. Biomechanics and Modeling in Mechanobiology, 20(3):861–878, 2021. doi: 10.1007/s10237-020-01407-3.
[28] M.M. Bhatti, S.Z. Alamri, R. Ellahi, and S.I. Abdelsalam. Intra-uterine particle–fluid motion through a compliant asymmetric tapered channel with heat transfer. Journal of Thermal Analysis and Calorimetry, 144(6):2259–2267, 2021. doi: 10.1007/s10973-020-10233-9.
[29] A.R. Hadjesfandiari and G.F. Dargush. Polar continuum mechanics. arXiv preprint arXiv:1009.3252, 2010.
[30] A.R. Hadjesfandiari and G.F. Dargush. Couple stress theory for solids. International Journal of Solids and Structures, 48(18):2496–2510, 2011. doi: 10.1016/j.ijsolstr.2011.05.002.
[31] A.R. Hadjesfandiari, G.F. Dargush, and A. Hajesfandiari. Consistent skew-symmetric couple stress theory for size-dependent creeping flow. Journal of Non-Newtonian Fluid Mechanics, 196:83–94, 2013. doi: 10.1016/j.jnnfm.2012.12.012.
[32] A.R. Hadjesfandiari, A. Hajesfandiari, and G.F. Dargush. Skew-symmetric couple-stress fluid mechanics. Acta Mechanica, 226(3):871–895, 2015. doi: 10.1007/s00707-014-1223-0.
[33] C.L.M.H. Navier. Mémoires de l’Académie Royale des Sciences de l’Institut de France. Royale des Sciences de l’Institut de France, 1823.
[34] I.M. Eldesoky, S.I. Abdelsalam, W.A. El-Askary, A.M. El-Refaey, and M.M. Ahmed. Joint effect of magnetic field and heat transfer on particulate fluid suspension in a catheterized wavy tube. BioNanoScience, 9(3):723–739, 2019. doi: >10.1007/s12668-019-00651-x.
[35] M.M. Bhatti and S.I. Abdelsalam. Thermodynamic entropy of a magnetized ree-eyring particle-fluid motion with irreversibility process: A mathematical paradigm. Journal of Applied Mathmatics nd Mechanics/Zeitschrift fur Angewandte Mathematik und Mechanik, 101(6):e202000186, 2021. doi: 10.1002/zamm.202000186.
[36] S. El-Sapa and N.S. Alsudais. Effect of magnetic field on the motion of two rigid spheres embedded in porous media with slip surfaces. The European Physical Journal E, 44(5):1–11, 2021. doi: 10.1140/epje/s10189-021-00073-2.
[37] K.P. Madasu, M. Kaur, and T. Bucha. Slow motion past a spheroid implanted in a Brinkman medium: Slip condition. International Journal of Applied and Computational Mathematics, 7(4):1–15, 2021. doi: 10.1007/s40819-021-01104-4.
[38] J. Happel and H. Brenner. Low Reynolds Number Hydrodynamics: with Special Applications to Particulate Media. Springer Science & Business Media, 2012.
[39] S. El-Sapa, E.I. Saad, and M.S. Faltas. Axisymmetric motion of two spherical particles in a brinkman medium with slip surfaces. European Journal of Mechanics-B/Fluids, 67:306–313, 2018. doi: 10.1016/j.euromechflu.2017.10.003.
[40] V.K. Stokes. Effects of couple stresses in fluids on the creeping flow past a sphere. The Physics of Fluids, 14(7):1580–1582, 1971. doi: 10.1063/1.1693645.
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Authors and Affiliations

Krishna Prasad Madasu
1
ORCID: ORCID
Priya Sarkar
1
ORCID: ORCID

  1. Department of Mathematics, National Institute of Technology, Raipur-492010, Chhattisgarh, India
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Abstract

The article describes motion planning of an underwater redundant manipulator with revolute joints moving in a plane under gravity and in the presence of obstacles. The proposed motion planning algorithm is based on minimization of the total energy in overcoming the hydrodynamic as well as dynamic forces acting on the manipulator while moving underwater and at the same time, avoiding both singularities and obstacle. The obstacle is considered as a point object. A recursive Lagrangian dynamics algorithm is formulated for the planar geometry to evaluate joint torques during the motion of serial link redundant manipulator fully submerged underwater. In turn the energy consumed in following a task trajectory is computed. The presence of redundancy in joint space of the manipulator facilitates selecting the optimal sequence of configurations as well as the required joint motion rates with minimum energy consumed among all possible configurations and rates. The effectiveness of the proposed motion planning algorithm is shown by applying it on a 3 degrees-of-freedom planar redundant manipulator fully submerged underwater and avoiding a point obstacle. The results establish that energy spent against overcoming loading resulted from hydrodynamic interactions majorly decides the optimal trajectory to follow in accomplishing an underwater task.
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Bibliography

[1] D.E. Whitney. Resolved motion rate control of manipulators and human prostheses. IEEE Transaction on Man-Machine System, 10(2):47–53,1969. doi: 10.1109/TMMS.1969.299896.
[2] Z. Shiller and H-H. Lu. Computation of path constrained time optimal motions with dynamic singularities. Journal of Dynamic Systems, Measurement, and Control, 114(1):34–40,1992. doi: 10.1115/1.2896505.
[3] N. Faiz and S.K. Agrawal.Trajectory planning of robots with dynamics and inequalities. In Proceedings IEEE International Conference on Robotics and Automation, pages 3976–3982, 2000. doi: 10.1109/ROBOT.2000.845351.
[4] S. Macfarlane and E.A. Croft. Jerk-bounded manipulator trajectory planning: design for realtime applications. IEEE Transactions on Robotics and Automation, 19(1):42–52, 2003. doi: 10.1109/TRA.2002.807548.
[5] G. Antonelli, S. Chiaverini, and N. Sarkar. External force control for underwater vehiclemanipulator systems. IEEE Transactions on Robotics and Automation, 17(6):931–938, 2001. doi: 10.1109/70.976027.
[6] D. Yoerger and J. Slotine. Robust trajectory control of underwater vehicles. IEEE Journal of Oceanic Engineering, 10(4):462–470, 1985. doi: 10.1109/JOE.1985.1145131.
[7] A. Alvarez, A. Caiti, and R. Onken. Evolutionary path planning for autonomous underwater vehicles in a variable ocean. IEEE Journal of Oceanic Engineering, 29(2):418–429, 2004. doi: 10.1109/JOE.2004.827837.
[8] N. Sarkar and T.K. Podder. Coordinated motion planning and control of autonomous underwater vehicle-manipulator systems subject to drag optimization. IEEE Journal of Oceanic Engineering, 26(2):228–239, 2001. doi: 10.1109/48.922789.
[9] J. Yuh. Modeling and control of underwater robotic vehicles. IEEE Transactions on Systems, Man and Cybernetics, 20(6):1475–1483, 1990. doi: 10.1109/21.61218.
[10] B. Lévesque and M.J. Richard. Dynamic analysis of a manipulator in a fluid environment. International Journal of Robotics Research, 13(3):221–231, 1994. doi: 10.1177/027836499401300304.
[11] T.I. Fossen. Guidance and Control of Ocean Vehicles. John Wiley, New York, 1994.
[12] G. Antonelli. Underwater Robots. 2nd ed. Springer, 2006.
[13] T.J. Tarn, G.A. Shoults, and S.P. Yang. A dynamic model of an underwater vehicle with a robotic manipulator using Kane’s method. Autonomous Robots, 3:269–283, 1996. doi: 10.1007/BF00141159.
[14] J.M. Hollerbach. A recursive Lagrangian formulation of manipulator dynamics and a comparative study of dynamics formulation complexity. IEEE Transactions on Systems, Man, and Cybernetics, 10(11):730–736, 1980. doi: 10.1109/TSMC.1980.4308393.
[15] J.N. Newman. Marine Hydrodynamics. 40th Anniversary Edition. The MIT Press, 2018.
[16] A. Kumar, V. Kumar, and S. Sen. Dynamics of underwater manipulator: a recursive Lagrangian formulation. In R. Kumar, V.S. Chauhan, M. Talha, H. Pathak (Eds.), Machines, Mechanism and Robotics, Lecture Notes in Mechanical Engineering, pages 555–570. Springer, Singapure, 2022. doi: 10.1007/978-981-16-0550-5_56.
[17] A.K. Sharma and S.K. Saha. Simplified drag modeling for the dynamics of an underwater manipulator. IEEE Journal of Ocean Engineering, 46(1):40–55, 2021. doi: 10.1109/JOE.2019.2948412.
[18] R. Colbaugh, H. Seraji, and K.L. Glass. Obstacle avoidance for redundant robots using configuration control. Journal of Robotics Systems, 6(6):721–744,1989. doi: 10.1002/rob.4620060605.
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Authors and Affiliations

Virendra Kumar
1
ORCID: ORCID
Soumen Sen
1
Shibendu Shekhar Roy
2

  1. Robotics and Automation Division, CSIR-Central Mechanical Engineering Research Institute, Durgapur, India
  2. Mechanical Engineering Department, National Institute of Technology, Durgapur, India

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