OBJECTIVES In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow ...

Viscoelastic liquids with very small amounts of polymer/surfactant additives can, as well known since B.A. Toms’ observation in 1948, provide substantial reductions in frictional drag of wall-bounded turbulence relative to the corresponding Newtonian fluid flow. Friction reductions of up to 80% compared to the pure water flow can be occasionally achieved with smooth channel/pipe flow of viscoel...

Friction drilling Process is a rotating conical tool to penetrate the work piece and create a bushing in a single step without generating chips. This work investigates the finite element modeling (FEM) of large plastic strain and high-temperature work-material deformation in friction drilling. The workmaterial deformation is very large, and both the tool and work piece temperatures are high in ...

The Problem of peristaltic transport of a fluid with magnetic fluid with variable viscosity through the gap between coaxial tubes where the outer tube is non-uniform with sinusoidal wave traveling down is wall and the inner tube is rigid. The relation between the pressure gradient, friction force on the inner and outer tube are obtained in terms of magnetic fluid and viscosity. The numerical so...

Data of flume experiments with bed forms are used to analyze and compare different roughness predictors. In this study, the hydraulic roughness consists of grain roughness and form roughness. We predict the grain roughness by means of the size of the sediment. The form roughness is predicted by three approaches: Van Rijn (1984), Vanoni & Hwang (1967) and Engelund (1966). The total roughness val...

The aim of this paper is to introduce numerical procedures to calculate the flow parameters in the bladed space of a cylindrically bladed radial-flow fan-impeller. The characteristics of the flow belonging to different duty points of the fan were determined by the numerical procedure. In this calculation, the blade effects as well as the effects of the fluid friction and the turbulence were tak...

The damage caused by landslide disasters is very significant. Among them, landslides after forest fires have been widely concerned scholars in recent years due to their particular physical and chemical properties. This large-scale shear flow of particulate matter has similarities fluid systems. However, the discontinuity particle system, its process significant random characteristics. To invest...

The strength of granular material, specifically sand is of pivotal importance for understanding physical phenomena on other celestial bodies. However, relatively few experiments have been conducted to determine the dependence of strength properties on gravity. In this work, we experimentally investigated three measures of strength (peak, confined flow, and unconfined flow friction angle) in Ear...

Friction plays an important role in the behavior of flowing granular media. The effective friction coefficient is a description of shear strength in both slow and rapid flows of these materials. In this paper, we study the steady state effective friction coefficient μ in a granular material in two steps. First, we develop a new relationship between the steady state effective friction coefficien...