The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
B G Fernandes - One of the best experts on this subject based on the ideXlab platform.
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Axial flux segmented srm with a higher number of Rotor segments for electric vehicles
IEEE Transactions on Energy Conversion, 2013Co-Authors: Raghu Madhavan, B G FernandesAbstract:Motors for in-wheel electric vehicle application should have high specific torque. In addition, these motors should be rugged, insensitive to vibration, and temperature variation. Therefore, segmented Rotor switched reluctance motor (SSRM) could be an attractive alternative to permanent magnet-based motors, which are being used for this application. A limitation of SSRM is that it requires full pitch winding for its operation. Since, in-wheel motors have high diameter to axial length (D/L) ratio, SSRM of these dimensions would be bulky and has high copper loss due to full pitch winding. Hence, in this paper, a novel SSRM with nonoverlapping winding is proposed. This motor is an axial flux SSRM (AFSSRM) with toroidal winding arrangement. It has single-stator, dual-Rotor configuration with 12 stator poles and 16 Rotor segments on each Rotor Disc. Design procedure for AFSSRM is developed and a flowchart describing the design algorithm is presented. A finite element method-based simulation is carried out to verify the performance of the proposed AFSSRM. In order to validate the performance of the motor, a prototype is fabricated and experimental results are presented.
Patrick Hayden - One of the best experts on this subject based on the ideXlab platform.
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Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: S. Aubrun, P. E. Hancock, Sylvain Loyer, Patrick HaydenAbstract:Experimental results on the wake properties of a non-rotating simplified wind turbine model, based on the actuator Disc concept, and a rotating model, a three-blade wind turbine, are presented. Tests were performed in two different test sections, one providing a nominally decaying isotropic turbulent inflow (turbulence intensity of 4% at Rotor Disc location) and one providing a neutral atmospheric boundary layer above a moderately rough terrain at a geometric scale of 1:300 (determined from the combination of several indicators), with 13% of turbulence intensity at hub height. The objective is to determine the limits of the simplified wind turbine model to reproduce a realistic wind turbine wake. Pressure and high-order velocity statistics are therefore compared in the wake of both Rotor Discs for two different inflow conditions in order to quantify the influence of the ambient turbulence. It has been shown that wakes of rotating model and porous Disc developing in the modeled atmospheric boundary layer are indistinguishable after 3 Rotor diameters downstream of the Rotor Discs, whereas few Discrepancies are still visible at the same distance with the decaying isotropic turbulent inflow.
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Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: S. Aubrun, P. E. Hancock, Sylvain Loyer, Patrick HaydenAbstract:Experimental results on the wake properties of a non-rotating simplified wind turbine model, based on the actuator Disc concept, and a rotating model, a three-blade wind turbine, are presented. Tests were performed in two different test sections, one providing a nominally decaying isotropic turbulent inflow (turbulence intensity of 4% at Rotor Disc location) and one providing a neutral atmospheric boundary layer above a moderately rough terrain at a geometric scale of 1:300 (determined from the combination of several indicators), with 13% of turbulence intensity at hub height. The objective is to determine the limits of the simplified wind turbine model to reproduce a realistic wind turbine wake. Pressure and high-order velocity statistics are therefore compared in the wake of both Rotor Discs for two different inflow conditions in order to quantify the influence of the ambient turbulence. It has been shown that wakes of rotating model and porous Disc developing in the modeled atmospheric boundary layer are indistinguishable after 3 Rotor diameters downstream of the Rotor Discs, whereas few Discrepancies are still visible at the same distance with the decaying isotropic turbulent inflow. copy; 2013 Elsevier Ltd.
Kavuluri Venkata Ramana - One of the best experts on this subject based on the ideXlab platform.
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Theoretical Investigation of Stresses Induced at Blade Mounting Locations in Steam Turbine Rotor System
International Journal of Applied Mechanics and Engineering, 2019Co-Authors: D. Kiran Prasad, Kavuluri Venkata RamanaAbstract:Abstract One of the most common incipient losses of integrity in mechanical structures is the development and propagation of cracks. Especially in rotating members like steam turbine Rotors etc. cracks, because of their potential, cause catastrophic failures and are a grave threat to an uninterrupted operation and performance. A crack may propagate from some small imperfections on the surface of the body or inside of the material and it is most likely to appear in correspondence to high stress concentration. Crack propagation path is generally determined by the direction of maximum stress or by the minimum material strength. Hence determination of stresses induced has been the focus of attention for many researchers. In the present work, development of a mathematical model to determine the stresses induced in a rotating Disc of varying thickness is studied. This model is applied to a steam turbine Rotor Disc to determine the induced stresses and radial deflection. The mathematical modeling results are validated with the results obtained using Ansys package. The results of the present study will be useful in diagnosing the location and magnitude of maximum stress induced in the turbine Rotor Disc and stress intensity factor due to the presence of crack.
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Weight Function Approach for Semi Elliptical Crack at Blade Mounting Locations in Steam Turbine Rotor System
Periodica Polytechnica Mechanical Engineering, 2018Co-Authors: Damarla Kiran Prasad, Kavuluri Venkata RamanaAbstract:This paper presents analysis of stress intensity factors at blade mounting locations of steam turbine Rotor system. General expressions for the stresses induced in a rotating Disc are derived and these equations are applied to steam turbine Rotor Disc. It is observed that the radial stress increases instantly at blade mounting location which indicates the probability of crack initiation and growth. A semi elliptical crack is considered at that location and weight function approach is used to determine the stress intensity factors. The results are validated with the influence coefficient approach. The differences of present approach with influence coefficient approach are less than 3 %. Hence the present approach is suitable for determination of stress intensity factors in a semi elliptical crack at blade mounting locations of a steam turbine Rotor Disc.
Raghu Madhavan - One of the best experts on this subject based on the ideXlab platform.
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Axial flux segmented srm with a higher number of Rotor segments for electric vehicles
IEEE Transactions on Energy Conversion, 2013Co-Authors: Raghu Madhavan, B G FernandesAbstract:Motors for in-wheel electric vehicle application should have high specific torque. In addition, these motors should be rugged, insensitive to vibration, and temperature variation. Therefore, segmented Rotor switched reluctance motor (SSRM) could be an attractive alternative to permanent magnet-based motors, which are being used for this application. A limitation of SSRM is that it requires full pitch winding for its operation. Since, in-wheel motors have high diameter to axial length (D/L) ratio, SSRM of these dimensions would be bulky and has high copper loss due to full pitch winding. Hence, in this paper, a novel SSRM with nonoverlapping winding is proposed. This motor is an axial flux SSRM (AFSSRM) with toroidal winding arrangement. It has single-stator, dual-Rotor configuration with 12 stator poles and 16 Rotor segments on each Rotor Disc. Design procedure for AFSSRM is developed and a flowchart describing the design algorithm is presented. A finite element method-based simulation is carried out to verify the performance of the proposed AFSSRM. In order to validate the performance of the motor, a prototype is fabricated and experimental results are presented.
S. Aubrun - One of the best experts on this subject based on the ideXlab platform.
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Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: S. Aubrun, P. E. Hancock, Sylvain Loyer, Patrick HaydenAbstract:Experimental results on the wake properties of a non-rotating simplified wind turbine model, based on the actuator Disc concept, and a rotating model, a three-blade wind turbine, are presented. Tests were performed in two different test sections, one providing a nominally decaying isotropic turbulent inflow (turbulence intensity of 4% at Rotor Disc location) and one providing a neutral atmospheric boundary layer above a moderately rough terrain at a geometric scale of 1:300 (determined from the combination of several indicators), with 13% of turbulence intensity at hub height. The objective is to determine the limits of the simplified wind turbine model to reproduce a realistic wind turbine wake. Pressure and high-order velocity statistics are therefore compared in the wake of both Rotor Discs for two different inflow conditions in order to quantify the influence of the ambient turbulence. It has been shown that wakes of rotating model and porous Disc developing in the modeled atmospheric boundary layer are indistinguishable after 3 Rotor diameters downstream of the Rotor Discs, whereas few Discrepancies are still visible at the same distance with the decaying isotropic turbulent inflow.
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Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: S. Aubrun, P. E. Hancock, Sylvain Loyer, Patrick HaydenAbstract:Experimental results on the wake properties of a non-rotating simplified wind turbine model, based on the actuator Disc concept, and a rotating model, a three-blade wind turbine, are presented. Tests were performed in two different test sections, one providing a nominally decaying isotropic turbulent inflow (turbulence intensity of 4% at Rotor Disc location) and one providing a neutral atmospheric boundary layer above a moderately rough terrain at a geometric scale of 1:300 (determined from the combination of several indicators), with 13% of turbulence intensity at hub height. The objective is to determine the limits of the simplified wind turbine model to reproduce a realistic wind turbine wake. Pressure and high-order velocity statistics are therefore compared in the wake of both Rotor Discs for two different inflow conditions in order to quantify the influence of the ambient turbulence. It has been shown that wakes of rotating model and porous Disc developing in the modeled atmospheric boundary layer are indistinguishable after 3 Rotor diameters downstream of the Rotor Discs, whereas few Discrepancies are still visible at the same distance with the decaying isotropic turbulent inflow. copy; 2013 Elsevier Ltd.
