This article addresses the analysis of the mechanism of natural air flow around the residential buildings  and the effect of the form of residential buildings on air flow among four building forms in Tehran. The aim of this research is to study the effect of the form of residential buildings on the mechanism of natural air flow with the purpose of optimally utilizing clean air. The research me...

In this paper, size distribution of nano-bubbles was measured by the reliable and fast method of laser diffraction technique. Nano-bubbles were produced using a nano-bubble generator designed and made based on hydrodynamic cavitation phenomenon in Venturi tubes. A Central Composite Design with Response Surface Methodology was used to conduct a five factor, five level factorial experimental desi...

In this work, the effects of the types of frother (MIBC, pine oil, and A65) and operational parameters (impeller speed and air flow rate) on the flotation of quartz coarse particles was investigated using nano bubbles (NBs). Quartz particles of the size of -425+106 mm and three types of frother were used for the flotation experiments. Also the impeller speed was 600 to 1300 rpm, and the air flo...

High speed wind tunnels are widely used in the study of fluid flow behavior around various objects. The air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. To arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

In this paper, numerical investigation of upward two phase flow of air-water has been studied. Different conditions of flow regimes including annular, wispy annular, slug, churn and bubbly are simulated based on Hewitt and Roberts map, and a good agreement between the experimental data of the map and the numerical simulation has been observed. Accordingly, a proper CFD model in CFD software of ...

green fig, which is usually consumed as dry fruit, is one of the important non-oil export agricultural commodities of iran. in this study, some important physical properties of green figs including geometric mean diamter, sphericity, porosity, particle and bulk density and pressure drop across a thin bed were measured at constant moisture content of 6% (dry basis). air flow ranges used in this ...

The results of measurements of peak flow made on 2,891 office workers and others attending a public health exhibition in the City of London have been analysed. After standardizing for height, peak flow was found to increase with age into the third decade before declining again, and there was evidence of a more rapid decline among continuing smokers than among those who had never smoked or had g...

A drop impacting a solid surface with sufficient velocity will splash and emit many small droplets. However, lowering the ambient air pressure suppresses splashing completely. This effect, robustly found for different liquid and substrate properties, raises the fundamental question of how air affects a spreading drop. In a combined experimental and numerical study we characterize the flow of ai...