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Extended kinetic theory applied to inclined granular flows: role of boundaries

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Abstract

We compare the predictions of extended kinetic theory (EKT), where the roles of surface friction and correlation in fluctuation velocities are taken into account, with discrete element simulations of steady, fully-developed, inclined flows of identical spheres over bumpy bases, in the presence and absence of flat, frictional sidewalls. We show that the constitutive relation for the pressure of EKT must be modified in the proximity of the boundary, because of the influence of excluded volume and shielding associated with collisions of particles with the boundary itself. We also note that currently available boundary conditions for flows over bumpy planes in kinetic theory underestimate the energy dissipation. These two observations explain the lack of agreement of EKT with the simulations, in terms of the maximum angles of inclination for which steady, fully-developed flows are possible. That is, for some high angles of inclination, EKT does not have solutions, while steady flows are predicted in DEM. However, whenever a solution to the system of differential equations of EKT does exist, the predicted distributions of velocity, solid volume fraction and granular temperature satisfactorily match the numerical measurements. The incompressible, algebraic approximation of EKT, which ignores the conduction of energy in the energy balance, admits solutions for a wider range of angles of inclination, as in the simulations, but fails to reproduce the quantitative and qualitative behaviour of solid volume fraction and granular temperature in the two conductive layers at the top and bottom of the flow. When frictional sidewalls are added to the domain, we show that the spanwise ratio of shear stress to pressure is linearly distributed in the dense core region of the flow, confirming that the sidewalls exert, on average, a Coulomb-like resistance to the flow with an effective friction coefficient which is less than half the actual particle-wall friction.

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References

  1. Azanza, E., Chevoir, F., Moucheront, P.: Experimental study of collisional granular flows down an inclined plane. J. Fluid Mech. 400, 199–227 (1999)

    Article  ADS  MATH  Google Scholar 

  2. Pouliquen, O.: Scaling laws in granular flows down rough inclined planes. Phys. Fluids 11(3), 542–548 (1999)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  3. Louge, M.Y., Keast, S.C.: On dense granular flows down flat frictional inclines. Phys. Fluids 13(5), 1213–1233 (2001)

    Article  ADS  MATH  Google Scholar 

  4. Jop, P., Forterre, Y., Pouliquen, O.: Crucial role of sidewalls in granular surface flows: consequences for the rheology. J. Fluid Mech. 541, 167–192 (2005)

    Article  ADS  MATH  Google Scholar 

  5. Hanes, D.M., Walton, O.R.: Simulations and physical measurements of glass spheres flowing down a bumpy incline. Powder Technol. 109(1–3), 133–144 (2000)

    Article  Google Scholar 

  6. Silbert, L.E., Ertas, D., Grest, G.S., Halsey, T.C., Levine, D., Plimpton, S.J.: Granular flow down an inclined plane: Bagnold scaling and rheology. Phys. Rev. E 64(5), 051302 (2000)

    Article  ADS  Google Scholar 

  7. Weinhart, T., Thornton, A.R., Luding, S., Bokhove, O.: Closure relations for shallow granular flows from particle simulations. Granul. Matter 14(4), 531–552 (2012)

    Article  Google Scholar 

  8. Brodu, N., Delannay, R., Valance, A., Richard, P.: New patterns in high-speed granular flows. J. Fluid Mech. 769, 218–228 (2015)

    Article  ADS  Google Scholar 

  9. Delannay, R., Louge, M., Richard, P., Taberlet, N., Valance, A.: Towards a theoretical picture of dense granular flows down inclines. Nat. Mater. 27, 99108 (2007)

    Google Scholar 

  10. Taberlet, N., Richard, P., Henry, E., Delannay, R.: The growth of a super stable heap: an experimental and numerical study. EPL (Europhys. Lett.) 68(4), 515 (2004)

    Article  ADS  Google Scholar 

  11. Jenkins, J.T., Savage, S.B.: A theory for the rapid flow of identical, smooth, nearly elastic, spherical particles. J. Fluid Mech. 130, 187–202 (1983)

    Article  ADS  MATH  Google Scholar 

  12. Lun, C.K.K.: Kinetic theory for granular flow of dense, slightly inelastic, slightly rough spheres. J. Fluid Mech. 233, 539–559 (1991)

    Article  ADS  MATH  Google Scholar 

  13. Garzó, V., Dufty, J.W.: Dense fluid transport for inelastic hard spheres. Phys. Rev. E 59(5), 5895–5911 (1999)

    Article  ADS  Google Scholar 

  14. Torquato, S.: Nearest-neighbour statistics for packing of hard spheres and disks. Phys. Rev. E 51, 3170 (1995)

    Article  ADS  Google Scholar 

  15. MiDi, G.D.R.: On dense granular flows. Eur. Phys. J. E 14(4), 341–365 (2004)

    Article  Google Scholar 

  16. Kamrin, K., Koval, G.: Nonlocal constitutive relation for steady granular flow. Phys. Rev. Lett. 108(17), 178301 (2012)

    Article  ADS  Google Scholar 

  17. Forterre, Y., Pouliquen, O.: Flows of dense granular media. Annu. Rev. Fluid Mech. 40(1), 1–24 (2008)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  18. Jenkins, J.T., Zhang, C.: Kinetic theory for identical, frictional, nearly elastic spheres. Phys. Fluids 14(3), 1228–1235 (2002)

    Article  ADS  Google Scholar 

  19. Chialvo, S., Sundaresan, S.: A modified kinetic theory for frictional granular flows in dense and dilute regimes. Phys. Fluids 25(7), 070603 (2013)

    Article  ADS  Google Scholar 

  20. Mitarai, N., Nakanishi, H.: Velocity correlations in dense granular shear flows: effects on energy dissipation and normal stress. Phys. Rev. Lett. 75(3), 031305 (2007)

    ADS  Google Scholar 

  21. Jenkins, J.T.: Dense inclined flows of inelastic spheres. Granul. Matter 10(1), 47–52 (2007)

    Article  MATH  Google Scholar 

  22. Berzi, D.: Extended kinetic theory applied to dense, granular, simple shear flows. Acta Mech. 225(8), 2191–2198 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  23. Berzi, D., Vescovi, D.: Different singularities in the functions of extended kinetic theory at the origin of the yield stress in granular flows. Phys. Fluids 27(1), 013302 (2015)

    Article  ADS  Google Scholar 

  24. Berzi, D., Jenkins, J.T.: Steady shearing flows of deformable, inelastic spheres. Soft Matter 11(14), 4799–4808 (2015)

    Article  ADS  Google Scholar 

  25. Chialvo, S., Sun, J., Sundaresan, S.: Bridging the rheology of granular flows in three regimes. Phys. Rev. Lett. 85(2), 021305 (2012)

    ADS  Google Scholar 

  26. Vescovi, D., Berzi, D., Richard, P., Brodu, N.: Plane shear flows of frictionless spheres: kinetic theory and 3D soft-sphere discrete element method simulations. Phys. Fluids 26(5), 053305 (2014)

    Article  ADS  Google Scholar 

  27. Jenkins, J.T., Berzi, D.: Dense inclined flows of inelastic spheres: tests of an extension of kinetic theory. Granul. Matter 12(2), 151–158 (2010)

    Article  MATH  Google Scholar 

  28. Jenkins, J.T.: A chute flow of inelastic spheres. Prog. Theor. Phys. Suppl. 184, 49 (2010)

    Article  ADS  MATH  Google Scholar 

  29. Berzi, D., Jenkins, J.T.: Surface flows of inelastic spheres. Phys. Fluids 23(1), 013303 (2011)

    Article  ADS  Google Scholar 

  30. Jenkins, J.T., Berzi, D.: Kinetic theory applied to inclined flows. Granul. Matter 14(2), 79–84 (2012)

    Article  Google Scholar 

  31. Richman, M.W.: Boundary conditions based upon a modified Maxwellian velocity distribution for flows of identical, smooth, nearly elastic spheres. Acta Mech. 75(1), 227–240 (1988)

    Article  Google Scholar 

  32. Xu, H., Louge, M., Reeves, A.: Solutions of the kinetic theory for bounded collisional granular flows. Continu. Mech. Thermodyn. 15(4), 321–349 (2003)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  33. Thornton, A.R., Weinhart, T., Luding, S., Bokhove, O.: Frictional dependence of shallow-granular flows from discrete particle simulations. Eur. Phys. J. E 35(12), 127 (2012)

    Article  Google Scholar 

  34. www.mercurydpm.org

  35. Fuchs, R., Weinhart, T., Meyer, J., Zhuang, H., Staedler, T., Jiang, X., Luding, S.: Rolling, sliding and torsion of micron-sized silica particles: experimental, numerical and theoretical analysis. Granul. Matter 16(3), 281–297 (2014)

    Article  Google Scholar 

  36. Luding, S.: Introduction to discrete element methods. Eur. J. Environ. Civil Eng. 12(7–8), 785–826 (2008)

    Article  Google Scholar 

  37. Weinhart, T., Hartkamp, R., Thornton, A.R., Luding, S.: Coarse-grained local and objective continuum description of three-dimensional granular flows down an inclined surface. Phys. Fluids 125(7), 070605 (2013)

    Article  Google Scholar 

  38. Tunuguntla, D.R., Thornton, A.R., Weinhart, T.: From discrete elements to continuum fields: extension to bidisperse systems. Comput. Part. Mech. 3(3), 349–365 (2016)

    Article  Google Scholar 

  39. Goldhirsch, I.: Stress, stress asymmetry and couple stress: from discrete particles to continuous fields. Granul. Matter 12(3), 239–252 (2010)

    Article  MATH  Google Scholar 

  40. Ries, A., Brendel, L., Wolf, D.E.: Coarse graining strategies at walls. Comput. Part. Mech. 1(2), 177–190 (2014)

    Article  Google Scholar 

  41. Silbert, L.E., Grest, G.S., Plimpton, S.J., Levine, D.: Boundary effects and self-organization in dense granular flows. Phys. Fluids 14(8), 2637–2646 (2002)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  42. Saha, S., Alam, M.: Normal stress differences, their origin and constitutive relations for a sheared granular fluid. J. Fluid Mech. 795, 549–580 (2016)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  43. Kumaran, V.: Dynamics of dense sheared granular flows. Part II. The relative velocity distributions. J. Fluid Mech. 632, 145–198 (2009)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  44. Pasini, J.M., Jenkins, J.T.: Aeolian transport with collisional suspension. Philos. Trans. R. Soc. Lond. A Math. Phys. Eng. Sci. 363(1832), 1625–1646 (2005)

    Article  ADS  MATH  Google Scholar 

  45. Jenkins, J.T., Hanes, D.M.: The balance of momentum and energy at an interface between colliding and freely flying grains in a rapid granular flow. Phys. Fluids A Fluid Dyn. 5(3), 781–783 (1993)

    Article  ADS  Google Scholar 

  46. Carnahan, N.F., Starling, K.E.: Equation of state for non-attracting rigid spheres. J. Chem. Phys. 51(2), 635–636 (1969)

    Article  ADS  Google Scholar 

  47. Louge, M.Y.: Computer simulations of rapid granular flows of spheres interacting with a flat, fractional boundary. Phys. Fluids 6(7), 2253–2269 (1994)

  48. Jenkins, J.T.: Boundary conditions for collisional grain flows at bumpy, frictional walls. In: Pöschel, T., Luding, S. (eds.) Granular gases, pp. 125–139. Springer, Berlin (2001)

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Acknowledgements

The first author is supported by an Engineering and Physical Sciences Research Council (EPSRC) DTA Scholarship. We would like to thank Prof. James T. Jenkins for several fruitful discussions related to this work.

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Correspondence to Devis Gollin.

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Gollin, D., Berzi, D. & Bowman, E.T. Extended kinetic theory applied to inclined granular flows: role of boundaries. Granular Matter 19, 56 (2017). https://doi.org/10.1007/s10035-017-0738-1

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