in this paper, an approximate axisymmetric method is developed which can reliably calculate fully viscous hypersonic flow over blunt-nosed bodies. in this method, a maslen’s second-order pressure expression is used instead of the normal momentum equation. the combination of maslen’s second-order pressure expression and viscous shock layer equations is developed to accurately and efficiently com...

one of the most problems that limits use of turbomachines at high speed applications is cavitation. cavitation can damage casing and blades of turbopump, also can make unstability in system. inducer that was installed in front of main impeller can improve cavitation characteristic of system and increase static pressure just before entrance of centrifugal pump. specially in fuel feed system of l...

We tested the hypothesis that reductions of perfusion pressure distal to a flow-limiting coronary artery stenosis can directly impair perfusion of the subendocardial myocardium. Dogs were instrumented with an electromagnetic flowmeter probe and a variable occluder on the proximal left circumflex coronary artery. Coronary perfusion pressure was measured with a catheter distal to the occluder. Co...

in the present study, turbulent flow in channels of a plate heat exchanger with corrugated chevron plates has been simulated numerically using the commercial cfd package, fluent. unstructured mesh is used for discretizing the computational domain and simple algorithm is utilized to solve the pressure and velocity equations. there is a wide selection of different plate heat exchangers within the...

Abstract: During solidification and casting in metallic molds, the heat flow is controlled by the thermal resistance at the casting-mold interface. Thus heat transfer coefficient at the metal- mold interface has a predominant effect on the rate of heat transfer. In some processes such as low pressure and die-casting, the effect of pressure on molten metal will affect the rate of heat transfer a...

myocardial fractional flow reserve (ffr) is a new index of the functional significance of intermediate coronary stenoses that is calculated from pressure measurements made during coronary arteriography. the aim of this study was to evaluate the correlation between non-hyperemic coronary pressure dicrotic notch and fractional flow reserve (ffr). a consecutive of 114 patients (73 men and 41 women...

in this work, the feasibility study for design of a laboratory sample rde which has an annular geometry with diameter of 76 mm and length of 101 mm has been performed. detonation engines are expected to be used as propulsion system in aerospace applications in the future. several types of detonation engines are currently under examination, including the rotating detonation engine (rde). first, ...

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...

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...

Introduction: Arterial stiffness is an important predictor of cardiovascular risk. Several indices have been  introduced to estimate the arterial stiffness based on the changes in the brachial blood pressure. Since the  substitution  of  the  blood  pressure  changes  in  the  central  arteries  such  as  carotid  with  the  blood  pressure  changes in the brachial results in error in the blood...