Comprehension and Estimation of Windage Losses in Rotor Slotted Air Gaps of Electrical Machines using CFD-LES methods

Sadr, Sara; Abdelli, Abdenour; Ben-NachouaneIntuitive, Ayoub; Friedrich, Guy; Vivier, Stéphane

doi:10.1109/ecce.2019.8912698

Cited by 6 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The original calculation did not consider the air gap size, and losses were calculated for a certain range of loss coefficients. For these reasons, windage losses were calculated as in [20]:…”

Section: Methods Of Analysismentioning

confidence: 99%

See 1 more Smart Citation

Design and Optimization of a High-Speed Switched Reluctance Motor

et al. 2021

View full text Add to dashboard Cite

Currently, one of the most used motor types for high-speed applications is the permanent-magnet synchronous motor. However, this type of machine has high costs and rare earth elements are needed for its production. For these reasons, permanent-magnet-free alternatives are being sought. An overview of high-speed electrical machines has shown that the switched reluctance motor is a possible alternative. This paper deals with design and optimization of this motor, which should achieve the same output power as the existing high-speed permanent-magnet synchronous motor while maintaining the same motor volume. The paper presents the initial design of the motor and the procedure for analyses performed using analytical and finite element methods. During the electromagnetic analysis, the influence of motor geometric parameters on parameters such as: maximum current, average torque, torque ripple, output power, and losses was analyzed. The analysis of windage losses was performed by analytical calculation. Based on the results, it was necessary to create a cylindrical rotor shape. The rotor modification method was chosen based on mechanical analysis. Using thermal analysis, the design was modified to meet thermal limits. The result of the work was a design that met all requirements and limits.

show abstract

Section: Methods Of Analysismentioning

confidence: 99%

“…In this case, the Wendt method was chosen. The Wendt friction coefficient can be calculated for 400 < Re < 10 4 as [20]:…”

Section: Methods Of Analysismentioning

confidence: 99%

Design and Optimization of a High-Speed Switched Reluctance Motor

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Typically, the C d is determined empirically rather than through calculations [9,19]. In [20], the skin friction coefficient is calculated with the following expression.…”

Section: Fluid Damping Lossmentioning

confidence: 99%

“…Here, µ is the dynamic viscosity of the fluid and ϕ is the air gap length. There exist additional empirical calculations using various approaches [19]. However, these approaches consider the air gap to be a smooth cylinder and completely ignore the specific geometric characteristics of the air gap surface.…”

Section: Fluid Damping Lossmentioning

confidence: 99%

Investigating the Role of Stator Slot Indents in Minimizing Flooded Motor Fluid Damping Loss

Tekgun,

Tekgun

2023

Machines

View full text Add to dashboard Cite

This research examines how fluid damping loss affects the operation of a two-pole, 5.5 HP (4 kW) induction machine (IM) within the context of different slot opening configurations developed for downhole water pump applications. Since these motors operate with their cavities filled with fluid, the variations in fluid viscosity and density, compared to air, result in the occurrence of damping losses. Furthermore, this loss can be attributed to the motor’s stator and rotor surface geometry, as the liquid within the motor cavity moves unrestrictedly within the motor housing. This study involves the examination of the damping loss in a 24-slot IM under different stator slot indentations. The investigation utilizes computational fluid dynamics (CFD) finite element analysis (FEA) and is subsequently validated through experiments. The aim of this work is to emphasize the significance of fluid damping loss in submerged machines. Results reveal that the damping loss exceeds 8% of the motor output power when the stator surface has indentations, and it diminishes to 3.2% of the output power when a custom wedge structure is employed to eliminate these surface indentations.

show abstract

“…Sara Sadr et al [3] this article presents the use of CFD (Computational Fluid Dynamics) simulations to study air flows in very tight air spaces in high speed electric cars. For this purpose, the shear stress of the wall on the surface of the rotor, the coefficient of friction of the rotor skin and the losses due to the aging of the wind are numerically evaluated.…”

Section: Literature Reviewmentioning

confidence: 99%

Optimized Thermal Efficiency of Rotor and Stator Using CFD

Hussain

Pouranik

2020

IJOSCIENCE

View full text Add to dashboard Cite

The space between rotor and stator plays a very important role in the design and performance of rotating machinery. The thickness of the gap can vary considerably depending on the size and operating conditions for the different types of rotating machines. Analysis the air velocity and temperature distribution over the air flow gap in stator and motor. Changing the design of rotor to develop turbulence in air flow gap. Compare the velocity and temperature distribution of proposed design with previous studies. The simulation results pinpoint also the periodic heat transfer pattern from the rotor surface and this provides useful information for the prediction of the temperature distribution inside the rotating electrical machine. The simulation results of case-1 show about 117°C temperature inside the rotor machine. Then increase the number of slot inside the rotor machine the total temperature of the rotor machine decreases up to 76°C. Due to low temperature total efficiency of the system increases. And also reduces the loss due to heat. The turbulence effect inside the rotor increase in third case. Due to turbulence effect the air cover large amount of area inside the rotor. So total temperature of the rotor casing decreases. In a system where volume is held constant, there is a direct relationship between Pressure and Temperature. For this case, when the pressure increases then the temperature also increases. When the pressure decreases, then the temperature decreases. So pressure in third case decrease upto1.26Pa and temperature 76 °C.

show abstract

Comprehension and Estimation of Windage Losses in Rotor Slotted Air Gaps of Electrical Machines using CFD-LES methods

Cited by 6 publications

References 12 publications

Design and Optimization of a High-Speed Switched Reluctance Motor

Design and Optimization of a High-Speed Switched Reluctance Motor

Investigating the Role of Stator Slot Indents in Minimizing Flooded Motor Fluid Damping Loss

Optimized Thermal Efficiency of Rotor and Stator Using CFD

Contact Info

Product

Resources

About