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 it is attempted to investigate the behavior of an inviscid flow in the meridional plane of an axial flow compressor. for this purpose the 3-d unsteady euler equations in cylindrical coordinate are averaged in tangential direction. therefore, the equations are reduced to a 2-d system. by averaging the tangential component of momentum equation, a blade force will result. axial and r...

In this work, the feasibility of flow pattern and oil hold up the prediction for vertical upward oil–water two–phase flow using pressure fluctuation signals was experimentally investigated. Water and diesel fuel were selected as immiscible liquids. Oil hold up was measured by Quick Closing Valve (QCV) technique, and five flow patterns were identified using high-speed photo...

this paper presents a numerical simulation of developing flow and heat transfer of a viscoelastic fluid in a rectangular duct. in fully developed flow of a viscoelastic fluid in a non-circular duct, secondary flows normal to the flow direction are expected to enhance the rate of heat and mass transfer. on the other hand, properties such as viscosity, thermal conductivity, specific heat and rela...

Orifice flow meter is one of the most common devices in industry which is used for measuring the gas flow. This system includes an orifice plate, temperature and pressure transmitters, and a flow computer. The flow computer is used for collecting information related to temperature, pressure, and their differences under various conditions. Also the flow computer can calculate the flow rate of ga...

Background: The mechanisms underlying cerebral hypercapnic vasodilatation are not fully understood. Objective: To investigate the role of nitric oxide (NO) and ATP-sensitive potassium (KATP) channels in basal blood flow regulation and hypercapnia-induced vasodilatation in rabbit cerebral blood vessels. Methods: The change in cerebral blood flow was measured by a laser Doppler flowmeter in 18 Ne...

In this investigation, a mathematical model for studying oscillatory flow of blood in a stenosed artery under the influence of transverse magnetic field through porous medium has been developed. The equations of motion of blood flow are solved analytically. The analytical expressions for axial velocity, volumetric flow rate, pressure gradient, resistance to blood flow and shear stress have been...

mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. in this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numeri...