BACKGROUND Guidewire (GW) size and stenosis dimensions are the two major factors affecting the translesional pressure drop. Studying the combined effect of these parameters on the mean pressure drop (Δp) across the stenosis is of high practical importance. METHODS In this study, time averaged mass and momentum conservation equations are solved analytically to obtain pressure drop-flow, Δp-Q, ...

in this work, three-dimensional turbulent forced convection flow through a b-type section pipe, which porous material inserted at the bottom wall, is investigated numerically. the b-type section pipe are used in cooling systems, such as cars’ radiators. the main purpose of this research is to enhance heat transfer and to reduce the scales of such systems. the governing equations are formulated ...

conclusions results indicated that annular fluidized bed reactor’s adsorbers are useful techniques for vocs adsorption. comparison of two particle ranges indicates that in all concentrations and all flow rates of the experiments, smaller particle size adsorption are better. in superficial velocity above the minimum fluidization velocity, pressure drop of fluidized beds are less than the pressur...

In the region from arterial trunks to pial arterioles anatomical characteristics of the cerebral artery as revealed by quantitative treatment of the arterial cast consist in the predominance of the length of large arterial branches over that of the arterioles. Theoretical analysis of blood pressure drop based on the above result demonstrates a large pressure drop in the region of large arterial...

In this study, the air-side pressure drop and heat transfer performance of plate-fin and microchannel coils were tested under clean and fouled conditions. The heat exchangers were tested with two different types of dust, ASHRAE dust and Arizona Road Test Dust. The ASHRAE dust was found to have a very significant impact on the pressure drop of the microchannel heat exchanger, increasing the air-...

In this study, the air-side pressure drop and heat transfer performance of plate-fin and microchannel coils were tested under clean and fouled conditions. The heat exchangers were tested with two different types of dust, ASHRAE Standard Dust and Arizona Road Test Dust. The ASHRAE dust was found to have a very significant impact on the pressure drop of the microchannel heat exchanger, increasing...

The present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at Isfahan power plant. The difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. Distilled water/ silver ...

The peak pressure drop across the aortic valve in aortic stenosis has been measured by Doppler ultrasound. Maximum velocity in the Doppler signal from the aortic jet was recorded using a maximum frequency estimator. With an angle close to zero between ultrasound beam and maximal velocity in the jet, peak pressure drop can be calculated from the maximal velocity measured; a larger angle will und...

This second part of a two-part study explores the performance of a new cooling scheme in which the primary working fluid flowing through a micro-channel heat sink is indirectly cooled by a refrigeration cooling system. The objective of this part of study is to explore the pressure drop and heat transfer characteristics of the heat sink. During single-phase cooling, pressure drop decreased with ...

Nowadays, UnderBalanced Drilling (UBD) technology is widely applicable in the petroleum industry due to its advantages to an overbalanced drilling operation. UBD success depends on maintaining the drilling fluid circulating pressure below the reservoir pore pressure during operations. One of the main prerequisites of a successful UBD operation is the correct estimation of the pressure profi...