Fluid flow, heat transfer and entropy generation characteristics of micro-pipes are investigated computationally by considering the simultaneous effects of pipe diameter, wall heat flux and Reynolds number in detail. Variable fluid property continuity, Navier-Stokes and energy equations are numerically handled for wide ranges of pipe diameter (d = 0.50–1.00 mm), wall heat flux ( ' ' q = 1000–20...

This paper pRisents nwneric:a.l analysis of the incompressible turbulent flow field in a single cavity of the stepped multi-cavity seal. The dimensionless bulk pressure drop for the cavity with and without groove has been investigated for four different Reynolds numbers and three different shaft ro~ating speeds. SIMPLER algoritlun is applied to solve the NavierStokes equation and lowReynolds nu...

tion with laboratory experiment, can provide valuable insight into complex biological systems that involve the interaction of an elastic structure with a viscous, incompressible fluid. This biological fluid-dynamics setting presents several more challenges than those traditionally faced in computational fluid dynamics—specifically, dynamic flow situations dominate, and capturing time-dependent ...

The use of an artificial roughness on a surface of absorber plate is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. This paper presents a comparison of parameters that enhance the heat transfer coefficient thus efficiency ofa solar air heater for different artificially roughened geometries for the Reynolds number from 2500 -18000. Th...

Inertial microfluidics has emerged as an important tool for manipulating particles and cells. For a better design of inertial microfluidic devices, we conduct 3D direct numerical simulations (DNS) and experiments to determine the complicated dependence of focusing behaviour on the particle size, channel aspect ratio, and channel Reynolds number. We find that the well-known focusing of the parti...

A finite difference/front tracking method is used to study the motion of three-dimensional deformable drops suspended in plane Poiseuille flow at non-zero Reynolds numbers. A parallel version of the code was used to study the behavior of suspension on a reasonable grid resolution (grids). The viscosity and density of drops are assumed to be equal to that of the suspending medium. The effect of ...

The flow of viscoelastic liquids with constant shear viscosity through symmetric sudden expansions is studied by numerical means. The geometry considered is planar and the constitutive model follows the modified FENE-CR equation, valid for relative dilute solutions of polymeric fluids. For Newtonian liquids in a 1:3 expansion we predict the result that the flow becomes asymmetric for a Reynolds...

Stokes Paradox, Fluid dynamics, Stokes flow, Stream function, Biharmonic equation, Helmholtz equation, Low Reynolds number This paper proposes a solution to Stokes’ paradox for asymptotically uniform viscous flow around a cylinder. The existence of a global stream function satisfying a perturbative form of the two-dimensional Navier–Stokes equations for low Reynolds number is established. This ...

The path to turbulence in the wake of cylinders with square crosssection is investigated by means of direct numerical simulation, employing a two-dimensional spectral element method and Floquet linear stability analysis. The critical Reynolds number for the onset of the three-dimensional instability modes A, B, C and QP are reported for cylinder incidence angles between 0° and 45°. The Strouhal...

An entirely new approach to the large-eddy simulation (LES) of high-speed compressible turbulent flows is presented. Subgrid scale stress models are proposed that are dimensionless functions of the computational mesh size times a Reynolds stress model. This allows a DNS to go continuously to an LES and then a Reynolds-averaged Navier-Stokes (RANS) computation as the mesh becomes successively mo...