In this paper, the scale effects are specifically addressed by conducting experiments with air flow in different microtubes. Three stainless steel tubes of 962, 308, and 83 μm inner diameter (ID) are investigated for friction factor, and the first two are investigated for heat transfer. Viscous heating effects are studied in the laminar as well as turbulent flow regimes by varying the air flow ...

bendway weirs are an important tool in multi-purpose erosion control and are implemented to control erosion, restore streams, and improve habitat. these structures create a hydraulic effect that reduces erosion on the outer bank of a bend by reducing flow velocities near the outer bank and reduce the concentration of currents on the outer bank creating better current alignment through the bend....

The inertial migration of spherical particles in a circular Poiseuille flow is numerically investigated for the tube Reynolds number up to 2200. The periodic boundary condition is imposed in the streamwise direction. The equilibrium positions, the migration velocity, and the angular velocity of a single particle in a tube cell are examined at different Reynolds numbers, particle-tube size ratio...

this paper presents a three-dimensional numerical investigation carried out in turbulent forced convection in a tube with helical ribs. enhancement of heat transfer using helically corrugated tubes has beenstudied experimentally by many researchers but there exist a few published numerical analyses results. the paper also introduces the results of heat transfer and friction factor data for inco...

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...

A two-dimensional transient axi-symmetric model was developed to study the effects of various thermal and geometric parameters on cyclic heating and cooling modes of a phase-change thermal energy storage system. The high-temperature thermal energy storage device utilizes LiH for heat sink applications to store the waste heat generated during power-burst periods. The stored heat is then discharg...

The complexity of the mechanics involved in the mammalian reproductive process is evident. Neither an ovum nor an embryo is self-propelled, but move through the oviduct or uterus due to the peristaltic action of the tube walls, imposed pressure gradients, and perhaps ciliary motion. Here we use the method of regularized Stokeslets to model the transport of an ovum or an embryo within a peristal...

This study compares three different nozzle flow configurations—central liquid jet with surrounding gas phase, sheet central and inner outer phases. To guarantee constant velocities, as well momentum flows at the orifice, a identical orifice areas (a tube slits) was utilized in experiments. The influence of velocity (GLR), dynamic viscosity liquid, configuration on resulting droplet sizes (D32, ...

Two-phase flow regimes are affected by conduit position, alignment, geometry, flow direction, physical characteristics, and flow rate of each phase as well as the heat flux toward the boundaries. Due to the importance of two-phase flow, numerous regimes have been identified. The first step in studying micro-bubble formation inside a venturi tube is to recognize the type of flow regimes. In this...

A detailed investigation of the Raman response of the inner tube radial breathing modes (RBMs) in double-wall carbon nanotubes is reported. It revealed that the number of observed RBMs is two to three times larger than the number of possible tubes in the studied frequency range. This unexpected increase in Raman lines is attributed to a splitting of the inner tube response. It is shown to origi...