In this paper, a modified two-fluid model has been adopted to simulate the process of upward vertical subcooled flow boiling of refrigerant R-113 in a vertical annular channel at low pressure. The modified model considers temperature dependent properties and saturation temperature variation and was validated against a number of published low-pressure subcooled boiling experiments. The results s...

We compared three different tracheal wall pressure measuring techniques in vitro. Using a high-volume, low-pressure, cuffed tracheal tube with an internal diameter of 7.5 mm and a model trachea, the pressure difference technique, the wall pressure membrane technique and the microchip sensor probe technique with and without lubrication were studied. Wall pressures were measured after sequential ...

the purpose of this research is to numerically investigate the interaction of pulsatile flow of blood with an axisymmetric artery in various percentages of stenosis. the carreau non-newtonian model and the generalized maxwell rheological model were used to model the blood fluid and the viscoelastic wall of arterial, respectively. the innovation of the present research is modeling of viscoelasti...

inclined retaining walls with slopes less than perpendicular are appropriate candidates in several engineering problems. yet, to the knowledge of authors, only a few analytical solution for calculation of active earth pressure on such walls, which will be usually smaller than the same pressure on vertical ones, has been presented neither in research papers nor in design codes. considering limit...

volumetric techniques were employed to study the adsorption of co2 on a purified multi-wall carbon nanotubes (mwnt’s) sample, as a mesoporous material, at isothermal conditions of 288, 293 and 298 k and pressures ranging from 30 to 150 kpa. langmuir, freundlich and sips equations were used to represent the isotherms. also the parameters of these fitted isotherm models have been determined. the ...

This article reports the active control of base flows using the experimental procedure. Active control of base pressure helps in reducing the base drag in aerodynamic devices having suddenly expanded flows. Active control in the form of microjets having 0.5 mm radius placed at forty-five degrees apart is employed to control the base pressure. The Mach numbers of the present analysis are 1.7, 2....

the model fluids containing hard ellipses (hes) and gay-berne (gb) particles where their center is moving in one dimension and confined between two parallel walls with different interactions are investigated using monte carlo simulation, nvt ensemble. the dependency of fluid pressure with respect to the wall distances is studied. the oscillatory behaviors are seen in this quantity against wall ...

The two-fluid flow is produced by the combined effects of electroosmotic force in a conducting liquid and pressure gradient force in a non-conducting liquid. The Poisson-Boltzmann and Navier-Stokes equations are solved analytically; and the effects of governing parameters are examined. Poiseuille number increases with increasing the parameters involved. In the absence of pressure gradient, the ...

calculation of lateral earth pressure on retaining walls is one of the main issues in geotechnics. the upper and lower bound theorems of plasticity are used to analyze the stability of geotechnical structures include bearing capacity of foundations, lateral earth pressure on retaining walls and factor of safety of slopes. in this paper formulation of finite element limit analysis is introduced ...