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Solids moving with a gas stream in a pipeline can be found in many industrial processes, such as power generation, chemical, pharmaceutical, food and commodity transfer processes. A mass flow rate of the solids is important characteristic that is often required to be measured (and controlled) to achieve efficient utilization of energy and raw materials in pneumatic conveying systems. The methods of measuring the mass flow rate of solids in a pneumatic pipeline can be divided into direct and indirect (inferential) measurements. A thermal solids' mass flow-meter, in principle, should ideally provide a direct measurement of solids flow rate, regardless of inhomogeneities in solids' distribution and environmental impacts. One key issue in developing a thermal solids' mass flow-meter is to characterize the heat transfer between the hot pipe wall and the gas-solids dense phase flow. The Eulerian continuum modeling with gas-solid two phases is the most common method for pneumatic transport. To model a gas-solid dense phase flow passing through a heated region, the gas phase is described as a continuous phase and the particles as the second phase. This study aims to describe the heat transfer characteristics between the hot wall and the gas-solids dense phase flow in pneumatic pipelines by modeling a turbulence gas-solid plug passing through the heated region which involves several actual and crucial issues: selections of interphase exchange coefficient, near-wall region functions and different wall surface temperatures. A sensitivity analysis was discussed to identify the influence on the heat transfer characteristics by selecting different interphase exchange coefficient models and different boundary conditions. Simulation results suggest that sensitivity analysis in the choice of models is very significant. The simulation results appear to show that a combination of choosing the Syamlal-O'Brien interphase exchange coefficient model and the standard k-ℇ model along with the standard wall function model might be the best approach, by which, the simulation data seems to be closest to the experimental results. [ABSTRACT FROM AUTHOR]

A new model to estimate the flow in a fracture has been developed in this paper. This model used two sinusoidal-varying walls with different phases to replace the flat planes in the cubic law model. The steady laminar flow between non-symmetric sinusoidal surfaces was numerically solved. The relationships between the effective hydraulic apertures and the phase retardation for different amplitudes and wavelengths are investigated respectively. Finally, a formula of the effective hydraulic aperture of the fracture was carried out based on the numerical results. [ABSTRACT FROM AUTHOR]

Resistance problem of the overland flow on complex microrelief is intricated. The difficulty in evaluating the resistance mainly comes from the variety of flow status and the complex composition of the resistance. Finding out the correlation between resistance components and influence factors is believed valuable to this problem. Because experimental data in which the resistance components could be distinguished is dramatically short, the numerical Monte-Carlo method is employed. After several representative complex microrelief, surfaces are generated randomly with Monte-Carlo method. Series of detailed numerical simulations is carried out to discuss the resistance composition of the overland flow. Numerical experiments with different flow discharges and slopes are carried out on the generated surfaces. The resistance constitution regularity shown in these simulation results is discussed. Statistics of correlation between resistance component and its influence factors are obtained. [ABSTRACT FROM AUTHOR]

This paper numerically investigated the two-dimensional motion of a bead in shallow water down a steep rough bed via smoothed particle hydrodynamics (SPH). The motivation of this work is to study the mechanism of particle transport in shallow flows. The simulated results show agreement with the experimental data which also verifies the validity of SPH. Moreover, a series of numerical experiments are carried out to discuss the influences of bead material, slope gradient on the characteristics of bead motion and the state of shallow flow. [ABSTRACT FROM AUTHOR]

This paper considers supersymmetric fifth order evolution equations. Within the framework of symmetry approach, we give a list containing six equations, which are (potentially) integrable systems. Among these equations, the most interesting ones include a supersymmetric Sawada-Kotera equation and a novel supersymmetric fifth order KdV equation. For the latter, we supply some properties such as a Hamiltonian structures and a possible recursion operator. [ABSTRACT FROM AUTHOR]