Experimental and CFD investigation of a lumped parameter thermal model of a single-sided, slotted axial flux generator

Haw, Lim Chin; Airoldi, G.; Bumby, J.R.; Dominy, Robert; Ingram, Grant; Mahkamov, Khamid; Brown, Neil L.; Mebarki, Abdeslam; Shanel, M.

doi:10.1016/j.ijthermalsci.2010.03.018

Cited by 21 publications

(10 citation statements)

References 17 publications

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“…was the convective heat transfer rate of rotating cylinder. The Grashof number, Gr Dc , and the other form of rotating Reynolds number, Re ω , [56] were defined as Equations (10) and (11).…”

Section: Heat-conduction Modelmentioning

confidence: 99%

“…To cope with the high power density, the forced convective cooling scheme was employed at the expense of external power consumption. In this respect, the thermal performances for the air-cooled [6][7][8][9][10][11][12][13][14], water-cooled [15][16][17] and oil-cooled [18] electric motors were numerically and, or, experimentally studied. In addition to the relative low cooling capacity of the forced convective airflow, the emission of acoustic noise from the fan was a major problem.…”

Section: Introductionmentioning

confidence: 99%

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Heat Transfer and Thermal Management of Interior Permanent Magnet Synchronous Electric Motor

Hsieh

Cai

et al. 2019

Inventions

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Geometric complexities and multi-physical phenomena add difficulties for predicting the thermal field and hence thermal management of an electric motor. A numerical design model that combined electromagnetic and thermal-fluid analysis was proposed for disclosing the detailed temperature distributions of each component in an electric motor. The thermal fluid analysis implemented ANSYS-Fluent code to unravel the thermal field of the interior permanent magnet synchronous electric motor fitted with a smooth or novel spirally twisted channel in the cooling water jacket of a stator with and without shaft cooling. In accordance with the thermal powers converted from the various electromagnetic losses of the electric motor, the complex heat conduction model with realistic thermal boundary conditions was formulated. Initially, the turbulent flow structures and channel averaged Nusselt numbers of the spiral channels without and with the sectional twist were comparatively examined for acquiring the convective thermal boundary conditions in the water jacket. With the high thermal conductivity of the aluminum water jacket, the heat-transfer improvements from the smooth-spiral-channel conditions by using the twisted spiral channel were effective for reducing the average temperatures by about 10% but less effective for altering the characteristic thermal field in the water jacket. At 1290 < Dn < 6455 or 5000 < Re < 25,000 for the spiral channel flows, the channel average Nusselt numbers ratios between the smooth and twisted spiral channels were elevated to 1.18–1.09 but decreased with the increase of Dn or Re. A set of heat-transfer correlations for estimating the Nusselt numbers of Taylor flow in the rotor-to-stator air gap was newly devised from the data available in the literature. While the cooling effectiveness of the water jacket and shaft was boosted by the sectional twists along the spiral channel of the water jacket, the presence of Taylor flow in the annual air gap prohibited the effective rotor-to-stator heat transmission, leading to hot spots in the rotor. By way of airflow cooling through the rotating hollow shaft, the high temperatures in the rotor were considerably moderated. As the development of Taylor flow between the rotor and stator was inevitable, the development of active or passive rotor cooling schemes was necessary for extending the power density of an electric motor. Unlike the previous thermal circuit or lumped-parameter thermal model that predicted the overall temperatures of motor components, the present coupled electromagnetic and thermal-fluid model can reveal the detailed temperature distributions in an electric motor to probe the local hot spots of each component in order to avoid overheating at the early design stage.

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Section: Heat-conduction Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Thermal Management of Interior Permanent Magnet Synchronous Electric Motor

Hsieh

Cai

et al. 2019

Inventions

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show abstract

“…At boundaries which have multiple layers of material, the thermal resistances are added in series. The total interface thermal resistance is used to calculate the interface thermal conductance matrix (K link ) and added to the overall thermal conductance matrix (K) according to equation (5). The calculated interface thermal resistance carries with it uncertainty because of the nature of heat transfer across such a boundary as discussed earlier.…”

Section: Model Developmentmentioning

confidence: 99%

“…Lumped parameter thermal networks have been used to predict both fluid and solid domain temperatures in AFPM machines [3][4][5]. These are fast to solve and widely used in electrical machine design.…”

Section: Introductionmentioning

confidence: 99%

Transient thermal modelling of an Axial Flux Permanent Magnet (AFPM) machine with model parameter optimisation using a Monte Carlo method

Hey

Howey

Martinez-Botas

et al. 2011

Vehicle Thermal Management Systems Conference and Exhibition (VTMS10)

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This paper presents the development of a transient thermal model of the EVO Electric AFM 140 Axial Flux Permanent Magnet (AFPM) machine based on a hybrid finite difference and lumped parameter method. A maximum deviation between simulated and measured temperature of 2.4°C is recorded after using a Monte Carlo simulation to optimise model parameters representing a 53% reduction in temperature deviation. The simulated temperature deviations are lower than the measurement error on average and the thermal model is computationally simple to solve. It is thus suitable for transient temperature prediction and can be integrated with the system control loop for feed forward temperature prediction to achieve active thermal management of the system.

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“…Numerical models such as those used in a Computational Fluid Dynamics (CFD) analysis are preferred to study the effects of convective cooling in electric machines [7]. On the other hand, lumped parameter models have proven to be useful for on-line temperature monitoring in electric machines but are insufficient in predicting the internal convection heat transfer accurately [8].…”

Section: Introductionmentioning

confidence: 99%

Conjugate heat transfer analysis of an energy conversion device with an updated numerical model obtained through inverse identification

Hey

Malloy²,

Martinez-Botas

et al. 2015

Energy Conversion and Management

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Experimental and CFD investigation of a lumped parameter thermal model of a single-sided, slotted axial flux generator

Cited by 21 publications

References 17 publications

Heat Transfer and Thermal Management of Interior Permanent Magnet Synchronous Electric Motor

Heat Transfer and Thermal Management of Interior Permanent Magnet Synchronous Electric Motor

Transient thermal modelling of an Axial Flux Permanent Magnet (AFPM) machine with model parameter optimisation using a Monte Carlo method

Conjugate heat transfer analysis of an energy conversion device with an updated numerical model obtained through inverse identification

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