Molecular dynamics simulations are carried out to investigate the dynamic behavior of the slip length in thin polymer films confined between atomically smooth thermal surfaces. For weak wall-fluid interactions, the shear rate dependence of the slip length acquires a distinct local minimum followed by a rapid growth at higher shear rates. With increasing fluid density, the position of the local ...

Abstract: In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using simulated annealing algorithm. First, the simulation of a distillation column was performed by using the shortcut results and irreversibility in each tray was obtained. The area beneath the exergy loss profile was used as Irreversibility Index in the whole column. Then, First Opti...

This paper reports the numerical determination of the entropy generation due to heat transfer, mass transfer and fluid friction in steady state for laminar double diffusive convection, in an inclined enclosure with heat and mass diffusive walls, by solving numerically the mass, momentum, species conservation and energy balance equations, using a Control Volume FiniteElement Method. The influenc...

The friction coefficient was measured for developed flow of drag-reducing polymer solutions in tubes of 2, 5, 10, 20 and 52 mm i.d. Our results were processed along with other authors' data in terms of different parameters in order to investigate the possibility of developing a simple empirical method for the prediction of the pipe diameter effect on friction. We found that the drag-reduction c...

In order to increase the efficiency of the conveyance of the granular solids, a new experimental set-up is designed. The test rig has longitudinal trapezoidal slots in its conveying pipes. Through experimentation, a correlation for friction factor in terms of solid mass flow rate, fluid flow rate and Froude number is presented. It is shown that the mixture friction factor for pipes with inn...

The axial stress and deformation of high temperature high pressure deviated gas wells are studied. A new model is multiple nonlinear equation systems by comprehensive consideration of axial load of tubular string, internal and external fluid pressure, normal pressure between the tubular and well wall, and friction and viscous friction of fluid flowing. The varied temperature and pressure fields...

In this study, the three-dimensional magnetohydrodynamic (MHD) boundary layer of stagnation-point flow in a nanofluid was investigated. The Navier–Stokes equations were reduced to a set of nonlinear ordinary differential equations using a similarity transform. The similarity equations were solved for three types of nanoparticles: copper, alumina and titania with water as the base fluid, to inve...

In this paper, the axial stress and deformation of high temperature high pressure super-deep deviated gas wells are studied. A new model presents multiple nonlinear equation systems, which comprehensively consider the axial load of the tubular string, internal and external fluid pressure, normal pressure between the tube and well wall, friction and the viscous friction of fluid flowing under va...

This paper presents the effect of friction on the performance of spark ignition engine using gas mixture as working fluid. The results were compared to frictionless engine. Engine parameters that were studied include equivalence ratio, engine speed, break mean effective pressure (BMEP), and cycle thermal efficiency. It was found for the frictionless engine operating at 6000 rev min and stoichio...

Long-range hydrodynamics between colloidal particles or fibers is modelled by the fluid particle model. Two methods are considered to impose the fluid boundary conditions at colloidal surfaces. In the first method radial and transverse friction forces between particle and solvent are applied such that the correct friction and torque follows for moving or rotating particles. The force coefficien...