Measurements of Diabatic Flow in an Annulus With an Inner Rotating Cylinder

Becker, K.M.; Kaye, Joseph

doi:10.1115/1.3684335

Cited by 180 publications

(95 citation statements)

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“…The vertical axis is defined as a dimensionless height (a) Air gap mesh with groove slots at stator and rotor surfaces that the slots increase the temperature gradients at the wails. This improves the rate of heat transfer [9] in the annular flow.…”

Section: Mesh Velocity Vectors and Temperature Proffiesmentioning

confidence: 96%

Numerical and experimental modelling of gas flow and heat transfer in the air gap of an electric machine. Part II: Grooved surfaces

et al. 2005

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The study deals with the cooling of a high-speed electric machine through an air gap with numerical and experimental methods. The rotation speed of the test machine is between 5000~40000 r/rain and the machine is cooled by a forced gas flow through the air gap. In the previous part of the research the friction coefficient was measured for smooth and grooved stator cases with a smooth rotor. The heat transfer coefficient was recently calculated by a numerical method and measured for a smooth stator-rotor combination. In this report the cases with axial groove slots at the stator and/or rotor surfaces are studied. Numerical flow simulations and measurements have been done for the test machine dimensions at a large velocity range. At constant mass flow rate the heat transfer coefficients by the numerical method attain bigger values with groove slots on the stator or rotor surfaces. The results by the numerical method have been confirmed with measurements. The RdF-sensor was glued to the stator and rotor surfaces to measure the heat flux through the surface, as well as the temperature.

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Section: Mesh Velocity Vectors and Temperature Proffiesmentioning

confidence: 96%

Numerical and experimental modelling of gas flow and heat transfer in the air gap of an electric machine. Part II: Grooved surfaces

et al. 2005

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“…The Nusselt number for tangential air flow between concentric cylinders is given by Becker and Kaye [15] as a function of the Taylor number:…”

Section: Figure 2 Axial and Radial Thermal Networkmentioning

confidence: 99%

Thermal Modeling of a Mini Rotor-Stator System

Dikmen

Hoogt

Boer

et al. 2009

Volume 9: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B and C

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“…Jeng et al (2007) performed heat transfer measurement over the inner cylinder for Re=60-2400 and Ta =0-2922 with and without ribs by using thermocouples. Becker and Kaye (1962) experimentally showed that for Re=0-5900 and Ta =65-1175 the Nusselt number declined along with the through-flow Reynolds number and reached minimum (at Re=1592) before it increased again. Simmers and Cony (1979) experimentally showed that the Nusselt number decreased with the increase of the through-flow Reynolds number and it was nearly constant beyond a certain value of the through-flow Reynolds number for Re=0-3000 and Ta =200-6500.…”

Section: Introductionmentioning

confidence: 99%

Through-flow effects on Nusselt number and torque coefficient in Taylor-Couette-Poiseuille flow investigated by large eddy simulation

Ohsawa

Murata

Iwamoto

2016

JTST

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Flow in a concentric annular passage with a rotating inner cylinder, which is called Taylor-Couette flow, is important in industrial applications, such as electric motor which requires not only effective cooling of rotating shaft but also saving power required for the axis rotation. When the through flow is superposed, which is called Taylor-Couette-Poiseuille flow, it affects the cooling efficiency and the torque required for the axis rotation. To the authors' knowledge, previous studies have been focused on either the Nusselt number or the torque coefficient in the Taylor-Couette-Poiseuille flow. Therefore, it is difficult to estimate the through-flow effects on both of them under the same geometry and flow conditions. In this study, the through-flow effects on both the Nusselt number and the torque coefficient in the Taylor-Couette-Poiseuille flow under the same geometry and flow conditions were investigated by performing large eddy simulation. The through-flow Reynolds number, Re, was varied from 500 to 8000 under constant Taylor and Prandtl numbers of Ta=4000 and Pr=0.71, respectively. The Nusselt number and the torque coefficient had similar trend to each other with the increase of Re. They decreased by 25% for the change of Re from 0 to 1000 and were nearly constant for the change of Re from 4000 to 8000. Contribution of the advection, turbulent transport and diffusion terms to the Nusselt number and the torque coefficient were evaluated by using the equations proposed by the authors. The contribution of the advection term was nearly zero for Re from 500 to 8000, which was contrary to the case without through-flow (Re=0). As Re increased, the contribution of the turbulent transport term decreased but that of the diffusion term did not change so much. The friction factor in the axial direction varied as Re -0.75 of which power was between laminar (Re -1 ) and turbulent (Re -0.25 ) correlations in a smooth stationary pipe flow.

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Measurements of Diabatic Flow in an Annulus With an Inner Rotating Cylinder

Cited by 180 publications

References 0 publications

Numerical and experimental modelling of gas flow and heat transfer in the air gap of an electric machine. Part II: Grooved surfaces

Numerical and experimental modelling of gas flow and heat transfer in the air gap of an electric machine. Part II: Grooved surfaces

Thermal Modeling of a Mini Rotor-Stator System

Through-flow effects on Nusselt number and torque coefficient in Taylor-Couette-Poiseuille flow investigated by large eddy simulation

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