We determined effects of augmented inspiratory and expiratory intrathoracic pressure or abdominal pressure (Pab) excursions on within-breath changes in steady-state femoral venous blood flow (Qfv) and net Qfv during tightly controlled (total breath time = 4 s, duty cycle = 0.5) accessory muscle/"rib cage" (DeltaPab <2 cmH2O) or diaphragmatic (DeltaPab >5 cmH2O) breathing. Selectively augmenting...

A numerical modeling study is presented concerning the role of total pressure in gas-phase nucleation. We consider a generic self-clustering mechanism for particle production in which the cluster transport properties are assumed to scale with monomer properties. A steady-state isothermal plug flow reactor model is considered in which axial diffusion of gas species is allowed. Species conservati...

This paper explains some of the convergence behaviour of iterative implicit and defect correction schemes for the solution of the discrete steady Euler equations. Such equations are also commonly solved by (pseudo) time integration, the steady solution being achieved as the limit (for t ! 1) of the solution of a time-dependent problem. Implicit schemes are then often chosen for their favourable...

An infinite-server queueing model with state-dependent arrival process and exponential distribution of service time is analyzed. It assumed that the difference between value rate total becomes positive starting from a certain number customers in system. In this paper, until reaching by system called pseudo steady-state period (PSSP). Distribution duration PSSP, its raw moments simple approximat...

Abstract Two-dimensional numerical simulations were performed to study concurrent-flow flame spread over a thin solid in microgravity. The main variable is the ambient flow velocity. Results validated against recent microgravity experiments (Saffire) where samples 41?cm wide burned two different velocities. results showed that, when velocity increases, average radiative heat flux out of surface...

plate heat exchangers are widely used in industries due to their special characteristics, such as high thermal efficiency, small size, light weight, easy installation, maintenance, and cleaning. the purpose of this study is to consider the effect of depth, angle, and pitch of hemispheric chevrons on the convective heat transfer coefficient and pressure drop. in the simulation of the heat exchan...

in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...