The role of particle collisions in pneumatic transport

We analyse the dilute, steady, fully developed flow of relatively massive particles in a turbulent gas in the context of a vertical pipe. The idea is that the exchange of momentum in collisions between the grains and between the grains and the wall plays a significant role in the balance of forces in the particle phase. Consequently, the particle phase is considered to be a dilute system of colliding grains, in which the velocity fluctuations are produced by collisions rather than by the gas turbulence. The balance equations for rapid granular flow are modified to incorporate the drag force from the gas, and boundary conditions, based on collisional exchanges of momentum and energy at the wall, are employed. The turbulence of the gas is treated using a one-equation closure. A numerical solution of the resulting governing equations provides velocity and turbulent energy profiles in agreement with the measurements of Tsuji et al. (1984).

[1]  Said Elghobashi,et al.  A two‐equation turbulence model for two‐phase flows , 1983 .

[2]  Yoshinobu Morikawa,et al.  LDV measurements of an air-solid two-phase flow in a vertical pipe , 1984, Journal of Fluid Mechanics.

[3]  Donald L. Koch,et al.  Kinetic theory for a monodisperse gas–solid suspension , 1990 .

[4]  F. Pourahmadi,et al.  Modelling solid-fluid turbulent flows with application to predicting erosive wear , 1983 .

[5]  L. G. Gibilaro,et al.  A fully predictive criterion for the transition between particulate and aggregate fluidization , 1984 .

[6]  W. Reynolds.  Computation of Turbulent Flows , 1975 .

[7]  J. Jenkins,et al.  A theory for the rapid flow of identical, smooth, nearly elastic, spherical particles , 1983, Journal of Fluid Mechanics.

[8]  A. Berker,et al.  Hydrodynamics of gas-solid flow in a catalytic cracker riser: Implications for reactor selectivity performance , 1986 .

[9]  Said Elghobashi,et al.  Two-component LDA measurement in a two-phase turbulent jet , 1983 .

[10]  T. G. Cowling,et al.  The mathematical theory of non-uniform gases , 1939 .

[11]  K. Min.  Intensity of Particle Motion in Solid—Gas Suspension Flow , 1967 .

[12]  Franz Durst,et al.  On the motion of particles in turbulent duct flows , 1982 .

[13]  C. A. Depew,et al.  Experimentally Determined Mean Flow Characteristics of Gas-Solid Suspensions , 1972 .

[14]  Geoffrey F. Hewitt,et al.  Particle motion in a turbulent pipe flow , 1989 .

[15]  J. Hinze,et al.  TURBULENT FLUID AND PARTICLE INTERACTION , 1972 .

[16]  C. P. Chen,et al.  A turbulence closure model for dilute gas‐particle flows , 1985 .

[17]  R. Jackson,et al.  Gas‐particle flow in a vertical pipe with particle‐particle interactions , 1989 .

[18]  S. L. Soo,et al.  PIPE FLOW OF SUSPENSIONS , 1969 .

[19]  Z. Genchev,et al.  Effects of the motion of dust particles on turbulence transport equations , 1980, Journal of Fluid Mechanics.

[20]  H. K. Ihrig,et al.  Experimental Determination of Statistical Properties of Two-Phase Turbulent Motion , 1958 .

[21]  Jamshid M. Nouri,et al.  Particle motion and turbulence in dense two-phase flows , 1987 .