• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.472-481
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• 2006

In the conventional SRM with multi-rotor teeth, the air gap must be very small in order to drive the SRM in the saturation region that is necessary for high output torque. However, this leads to the problem of overheating; particularly in the case of a small-size SRM This paper discusses the design of a new type of SRM, namely the rolled rotor SRM. This new type does not require more than a single region of a very small airgap. This solves the overheating problem in the small size SRM. Moreover, the use of the rolled rotor, instead of the conventional toothed rotor, grades the airgap region in a fashion that gives a smooth variation in the reluctance and smooth shapes of both current and torque. The latter functional behavior is required in many applications such as servo applications. The paper first addresses general design steps of the rolled rotor SRM then proceeds to the simulation results of the new SRM in order to evaluate the advantages gained from the new design. In addition, this paper compares the torque ripples obtained from the new design to its equivalent conventional one.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.165-173
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• 2017

The aeromechanics predictions of HART I rotor obtained using a computational structural dynamics (CSD) code are evaluated against the wind tunnel test data. The flight regimes include low speed descending flight at an advance ratio of ${\mu}=0.151$ and cruise condition at ${\mu}=0.229$. A lifting-line based unsteady airfoil theory with C81 table look-up is used to calculate the aerodynamic loads acting on the blade. Either rolled-up free wake or multiple-trailer wake with consolidation (MTC) model is employed for the free vortex wake representation. The measured blade properties accomplished recently are used to analyze the rotor for the up-to-date computations. The comparison results on airloads and structural loads of the rotor show good agreements for descent flight and fair for cruise flight condition. It is observed that MTC model generally improves the correlation against the measured data. The structural loads predictions for all measurement locations of HART I rotor are investigated. The dominant harmonic response of the structural loads is clearly captured with MTC model.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.629-632
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• 2009

The polymeric desiccant rotor is made from the super absorbent polymer by ion modification. The moisture sorption capacity of the super desiccant polymer(SDP) is 4 to 5 times larger than those of common desiccant meterials such as silica gel or zeolite. It is also known that SDP can be regenerated even at the relatively low temperature. To fabricate the desiccant rotor, firstly the SDP was laminated by coating the SDP on polyethylene sheet. Then corrugated and rolled up into a rotor. The diameter, the depth, the dimensions of the corrugated channel, etc. were pre-determined from numerical simulation on the heat and mass transfer in the desiccant rotor. The dehumidification performance was tested in a climate chamber. The relevant tests were carried out at the process air inlet temperature of $32^{\circ}C$, the regeneration air inlet temperature of $60^{\circ}C$ and the inlet dew-point temperature of both the process air and the regeneration air of $18.5^{\circ}C$, when the rotation period is long, the moisture sorption is not effective. In the desiccant rotor developed in this study, the optimum rotation period is found about 350s at the regeneration temperature of $60^{\circ}C$. It was found from further experiments that the optimum rotation tends to decreases as the regeneration temperature increases. Meanwhile, the outlet temperature of the process air deceases monotonically as the rotation period increases.

• Journal of the Korean Magnetics Society
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• v.16 no.4
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• pp.211-215
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• 2006

Measurement methods in order to measure the mechanical properties nondestructively have been studied. The mechanical properties of the structural and turbine rotor steels are related with their magnetic properties. If the magnetic properties of the cold rolled carbon steel sheet (CR) for a car are measured nondestructively, its mechanical properties are analogized by their magnetic properties. And then the mechanical properties are monitored on-line by measuring the magnetic properties. We prepared three CR materials, CBQ 3060, CBQ 3041, and CBQ 3036, were prepared in order to measure their mechanical and magnetic properties. The Vickers hardness,yield strength, and tensile strength were measured by ASTM E 8M, and the reversible magnetic permeability was measured by the surface type probe. The coercivity calculated by the peak interval of reversible magnetic permeability increased linearly with the increase of Vickers hardness, yield strength, and tensile strength. The amplitude of the peak interval of reversible magnetic permeability drastically decreased when the lift-off was increased.