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In an effort to put more eyeballs on television sets, and in an attempt to reinvigorate a sport long beleaguered by doping scandals, recent questions surrounding female sponsorships, and a vanishing audience, the International Association of Athletic Federations unveiled a new camera designed by Seiko during the September 2019 World Championships held in Doha, Quatar. The idea was to add to an immersive experience, offering unparalleled views of sprinters at the moment they exploded from the starting blocks. Like many things during the Doha meet, the effort became an ending to a bad joke. Rather than getting to the heart of the event, the camera's focus was a bit lower; the Seiko angle became known derisively as the crotch shot. After objections by two female German sprinters the positioning of the camera angle (specifically what would be shown when) was reconsidered, reframed, and essentially retired. Control of the body, including how it is observed, and the closely related idea of the control of one's image are bound by certain ethical dimensions, particularly when that control is violated or profited from by outside parties. This paper interrogates how those concerns may be ameliorated by embracing an ethics of care. [ABSTRACT FROM AUTHOR]

In this paper, the determination of the end space induction motor heat transfer coefficients is presented, and the methodologies used are examined closely. Two 'ad hoc' prototypes have been built and a test bench completed. This paper reports the setup of the test procedures and results obtained in detail. As the end windings are the hottest points of the motor, particular care has been devoted to the determination of the heat transfer coefficient concerning the end-winding structure. The results obtained are of fundamental importance for the determination of the thermal resistances between end windings and end caps. These can then be used in thermal networks usually adopted in thermal model analysis. Index Terms--Heat transfer coefficients, induction motors, parameter identification, thermal model.

In this paper, the authors present an extended survey on the evolution and the modern approaches in the thermal analysis of electrical machines. The improvements and the new techniques proposed in the last decade are analyzed in depth and compared in order to highlight the qualities and defects of each. In particular, thermal analysis based on lumped-parameter thermal network, finite-element analysis, and computational fluid dynamics are considered in this paper. In addition, an overview of the problems linked to the thermal parameter determination and computation is proposed and discussed. Taking into account the aims of this paper, a detailed list of books and papers is reported in the references to help researchers interested in these topics. Index Terms--Computed fluid dynamic, electrical machines, finite-element analysis (FEA), lumped-parameter thermal network (LPTN), thermal model, thermal parameter identification.

This paper deals with the formulations used to predict convection cooling and flow in electric machines. Empirical dimensionless analysis formulations are used to calculate convection heat transfer. The particular formulation used is selected to match the geometry of the surface under consideration and the cooling type used. Flow network analysis, which is used to study the ventilation inside the machine, is also presented. In order to focus the discussion using examples, a commercial software package dedicated to motor cooling optimization (Motor-CAD) is considered. This paper provides guidelines for choosing suitable thermal and flow network formulations and setting any calibration parameters used. It may also be considered a reference paper that brings together useful heat transfer and flow formulations that can be successfully applied to thermal analysis of electrical machines. Index Terms--Dimensionless correlations, electrical machines, flow analysis, thermal model.

In this paper, the authors discuss the problem concerning the determination of some thermal parameters which are very complex to compute. These parameters play an important role in thermal networks usually adopted for electrical machine thermal analysis. In particular, in this paper, the following thermal parameters are analyzed: equivalent thermal resistance between external frame and ambient, equivalent thermal conductivity between winding and lamination, forced convection heat transfer coefficient between end winding and end-caps, radiation heat transfer coefficient between external frame and ambient, interface gap between lamination and external frame, air cooling speed, and the bearings effective thermal resistance. While the information given in this paper is mainly related to induction motors, it is also of general use for the designers of other types of machine. The reported results have been validated using induction motors with power ranges from a few kilowatts up to 1 MW. Index Terms--Electrical machines, induction motors, parameter identification, thermal model.

With the increasing pressures on electric motor manufacturers to develop smaller and more efficient electric motors, there is a trend to carry out more thermal analysis in parallel with the traditional electromagnetic design. It has been found that attention to thermal design can be rewarded by major improvements in the overall performance. Thus, there is a requirement for accurate and reliable thermal analysis models that can be easily incorporated into motor design software. In this paper, emphasis is given to thermal sensitivity analysis of totally enclosed fan-cooled induction motors. In particular, thermal parameters are modified and their effects on the temperature rise shown. The results are useful for identifying the most important thermal parameters and enable robust designs to be developed that are insensitive to manufacturing tolerances. Index Terms--Induction motors, sensitivity analysis, thermal analysis, thermal models.

The flux-MMF diagram has recently been used to predict torque ripple in different machine types. This paper describes a simple and elegant method, based on this technique, for predicting the effect of skew on torque ripple in permanent-magnet machines. Although it is well known that skewing minimizes torque ripple, the paper quantifies the difference in the extent of minimization between the electromagnetic torque ripple and the cogging torque. Index Terms - Skew, cogging, torque ripple.

An improved approach to predicting cogging torque in permanent magnet motors using the flux-MMF diagram technique is presented and validated. A brief review of cogging torque calculation and minimization techniques is included. It is shown that the flux-MMF diagram can be constructed for any one pole of a permanent magnet machine using the demagnetization characteristic of the permanent magnet; then by applying the principle of virtual work, cogging torque can be predicted. It is also shown that the flux-MMF diagram technique is a truly universal technique of cogging torque prediction and gives greater insight into many of the methods used for cogging torque minimization.

This paper uses the flux-MMF diagram to compare and contrast the torque production mechanism in seven common types of electric motor. The flux-mmf diagram is a generalized version of the flux-linkage versus current ([Psi]-i) diagram for switched-reluctance motors. It is illustrated for switched-reluctance, synchronous-reluctance, induction, brushless ac, brushless dc, interior PM and dc commutator motors. The calculated flux-MMF diagrams for motors with the same electromagnetic volume, airgap, slotfill, and total copper loss are shown and are used to compare the low-speed torque and torque ripple performance. The motor designs used were reasonably optimized using a combination of commercially available motor CAD packages and finite-element analysis.

The author considers a trio of films of recent vintage in which the primary narrator is sight impaired and consider the role memory and recollection play in the telling of their accounts. Each film – Notes on Blindness, Blue, and The Diving Bell and the Butterfly – are biographical and depicted in documentary or hybrid/stylised documentary format. Common threads and themes unite the seemingly disparate characters and these focus on water and waiting. How a 'sightless' scene is recreated for film is at the heart of this article. [ABSTRACT FROM AUTHOR]

A summary of the design theory associated with dc commutator motors is presented. This is followed by a detailed description of a Computer Aided Design program written specifically for this class of motor. The software engineering content is extremely important: Once the engineering design equations are developed and validated, the productivity of the design engineer depends critically on the efficiency and user-friendliness of the software itself. The program described in the main text permits the integration of the motor design with the design of the electronic controller, together with the simulation of the whole system. When sizing motors for a particular application, speed of execution and the flexibility to evaluate a wide range of design options and parameter variations are essential, while absolute accuracy is only of secondary importance.

The design of a new type of axially-laminated interior permanent magnet motor drive showing an extremely wide constant-power speed range which exceeds 7.5:1 is described. The effect on the field-weakening performance of the number of poles, the pole-piece material, the rotor bolt holes, the airgap size, the rotor insulation ratio, and the magnet type are analyzed using analytical and finite-element techniques. A 7.5-kW synchronous reluctance and a 7.5-kW interior permanent magnet axially-laminated rotor were built for a commercial induction motor stator and experimental low-speed and field-weakening results are presented.

A method is described for calculating the average and instantaneous torque of the synchronous reluctance motor from a knowledge of the trajectory of the phase flux-linkage versus phase current [i-[Psi]] waveform, i.e., the same method as used with the switched reluctance motor. This allows a direct comparison between torque production in the two motors to be made. Analytical and finite-element analysis both show that the [i-[Psi]] loci of the synchronous reluctance motor are ellipsoidal in shape and are not limited to the first and third quadrants as in the switched reluctance motor. The [i-[Psi]] loci of the synchronous reluctance motor are not bounded by the magnetization curves in the same sense as in the switched reluctance motor and rely upon mutual coupling between phases for correct operation.