Confined Granular Flow in Silos: Experimental and Numerical by Jacek Tejchman

By Jacek Tejchman

During constrained movement of bulk solids in silos a few attribute phenomena should be created, similar to: unexpected and critical bring up of wall stresses, assorted circulation styles, formation and propagation of wall and inside shear zones, fluctuation of pressures and, robust autogenous dynamic effects.

These phenomena haven't been defined or defined intimately but. the most goal of the experimental and theoretical examine provided during this e-book is to give an explanation for the above pointed out phenomena in granular bulk solids and to explain them with numerical FE types established by means of experimental results.

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Confined Granular Flow in Silos: Experimental and Numerical Investigations

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Extra resources for Confined Granular Flow in Silos: Experimental and Numerical Investigations

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29) has the general form σz = − γ mN + 1 z + Cz − mN . 31) γH   C = H mN σ z0 + . 32) Hence σz = − γ γ H H   z +  σ z0 +   mN + 1 mN + 1   z   mN . 34) and the solution (Eq. 33) has the form σz = − mN +1   H − 1 +   . e. e. 37) or If mN = –1, the following expression is the general solution of Eq. 27 σ z = −(C − γ ln z ) z . 38) By taking into account Eq. 40) σz =  If the upper solid boundary is unloaded (Eq. 34), Eq. 40 becomes σ z = γ z ln H. 41) In the silo apex (z = 0), the mean vertical normal stress is equal σz = 0 .

The calculated increase of the horizontal wall normal stress is assumed next along the whole height. Ad. b) If the silo has horizontal stiffeners at the bottom and at the top, the horizontal wall normal stress is increased uniformly along the silo height as χ × phe. 02β χ = 1 + 3β h d r t for for r/t ≤ 70, r/t ≥ 100. 65) 42 3 Analytical and Standard Approaches to Silos Notation: d – silo diameter, r – silo radius, A – cross-section area, u – internal circumference, a – outlet eccentricity, t – wall thickness, z – vertical co-ordinate, h – height, α – wall inclination in hopper to horizontal, ph – horizontal pressure, pv – vertical pressure, pn – pressure perpendicular to wall surface in hopper, pw– vertical friction traction, pb– vertical pressure on horizontal silo bottom, pL– overpressure, γ – volumetric weight, λ – pressure coefficient ph/pv, μ – wall friction coefficient pw/ph, δ – solid slope inclination, β – non-uniformity coefficient, ‘f ’ – filling, ‘e’– emptying.

E. the inclination of the tangential line to the MohrColoumb circle defining the major principal consolidation stress. For cohesionless bulk solids, this angle is equal to the internal friction angle (δ = φ). During filling, the vertical normal stress is higher than the horizontal normal stress, and during emptying the situation is inverse. 50) where δ is the effective internal friction angle (resistance measure against flow at stationary state). The distribution of the parameter M is depicted in Fig.

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