... friction multiplier is shown to decrease as channel diameter decreases due to the influence of viscous and surface tension forces. 06 09 2010 10 05 2011 15 08 2011 15 08 2011 air drag forced convection microchannel flow pattern formation surface tension two-phase flow...

... 2010 19 03 2011 04 04 2011 01 08 2011 01 08 2011 drag flow simulation forced convection laminar flow natural convection pipe flow turbulence viscosity buoyancy-influenced flow EVM heat loading mixed convection RANS “Mixed” convection flows occur where...

... 10 4 ≤ Ra m ≤ 10 8 . The Nu values are compared with values in the absence of the form drag term. The form drag due to the porous medium is found to influence Nu considerably. The effect of the form drag on Nu is studied by using a form drag modified Rayleigh number Ra C (extended from Ra m...

..., the effects of different forces (e.g., drag, thermophoretic, Brownian, and Saffman’s lift force) are also studied. None of the models is a good predictor for all the flow regions from near the stagnation region to far-field downstream of the jets. Overall speaking, both standard k - ε and Reynolds stress...

..., drag force accretion seems to be inevitable. A standard formula for estimating the drag force F d exerted on the flat plate is available from the fluid dynamics literature. The descriptive equations for the heat transfer rate Q mix and drag force F d , mix associated with the seven binary gas mixtures...

...D. A. Nield The alternative ways of modeling form drag in a porous medium saturated by a power-law fluid in current usage are discussed. It is argued that the best alternative is to use the same expression as that used in the case of a Newtonian fluid, but with a modified Forchheimer coefficient...

... of the initial wall heat flux into cooled rotor blades. During the spinning-up period, the rotor is spun up to nearly its nominal speed (from 0 rpm to 6200 rpm) resulting in preheating due to drag losses. The long duration of this experiment ( ∼ 450 s ) and the magnitude of the wall temperature increase result...

... out for laminar multidirectional thermofluid flow in an idealized pore geometry of foams with a wide range of geometry parameters. Semiheuristic models for pressure drop and heat transfer are developed from the results of simulations. A simplified solid-body drag equation with an extended high inertia...

...A. Nouri-Borujerdi; Arash M. Lavasani Pressure drag coefficient and heat transfer are experimentally investigated around a single noncircular cylinder in cross-flow under angle of attack 0 deg < α < 360 deg and Reynolds number 1.5 × 10 4 < Re eq < 4.8 × 10 4 based on equivalent diameter...

... as the vortex viscosity increases. Moreover, the study showed that there is a threshold value for vortex viscosity above which the flow over the cylinder never responds to perturbation and stays symmetric without vortex shedding. Regarding drag coefficient, the results have revealed that within the selected...

... to 3.594 cm for the wing-shaped tubes. Based on the recorded time distributions of velocity u f ( t ) and temperature T f ( t ) , time average Reynolds number Re ¯ , drag coefficient C ¯ d , and Stanton number St ¯ were calculated. In general, the drag coefficient and the Stanton number are smaller...

...Jinjia Wei; Yasuo Kawaguchi; Bo Yu; Ziping Feng Turbulent friction drag and heat transfer reductions and rheological characteristics of a very dilute cationic surfactant solution, cetyltrimethyl ammonium chloride (CTAC)/sodium salicylate ( NaSal ) aqueous solution, were experimentally investigated...

... are obtained for the drag and heat transfer coefficients that can be used for a wide range of the power-law index, and generalized Reynolds and Prandtl numbers. It is found that pseudoplastic fluids offer less skin friction and higher heat transfer coefficients than dilatant fluids. As a result, the drag...

... gradient. This variation can be traced directly to the governing equations for momentum and energy which dictate a more direct influence of pressure gradient on wall shear than on energy (heat) transfer. Surface roughness introduces a large pressure drag component to the net skin friction measurement...

... the bulk of the resistance is assumed to be in the continuous phase. Results show that the external Nusselt number significantly increases with electric field strength at all Reynolds numbers. Also, the drag coefficient increases with electric field strength. The enhancement in heat transfer is higher...

... for the drag and the average heat transfer coefficients which can be used for a wide range of Reynolds and Prandtl numbers. The results for both drag and heat transfer coefficients are in good agreement with experimental/numerical data for a circular cylinder. Drag coefficient as a function of Re D...

... small-diameter, thin-walled polymer tubes and this route is being pursued by industry. We propose the use of unique shaped tubes that are easily extruded using polymeric materials. The shaped tubes are streamlined to reduce form drag yet the inside flow passage is kept circular to maintain the pressure...

... are also given, which are somewhat lower in the ribbed channel than in channels with dimples and/or protrusions mostly because of higher rib form drag and friction factors. Contributed by the Heat Transfer Division for publication in the JOURNAL OF HEAT TRANSFER . Manuscript received by the Heat...

... transfer coefficient. It has been found that the principal axes of the permeability tensor (which controls the viscous drag in the low Reynolds number range) differ significantly from those of the Forchheimer tensor (which controls the form drag in the high Reynolds number range), The study also reveals...

... at the average bulk temperature, (2) fluid viscosity determined at the log-mean bulk temperature and (3) fluid viscosity replaced by a channel-length averaged fluid viscosity. The HDD model is inadequate because the temperature dependent fluid viscosity surprisingly affects both, viscous and form, global drag...