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S V Prabhu - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of Static Torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the coefficient of Static Torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides positive coefficient of Static Torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The coefficient of Static Torque variations decrease with the increase in the number of stages. However, the coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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experimental investigations on single stage modified savonius rotor
Applied Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius or modified forms of the conventional Savonius rotors are being investigated in an effort to improve the coefficient of power and to obtain uniform coefficient of Static Torque. To achieve these objectives, the rotors are being studied with and without central shaft between the end plates. Tests in a closed jet wind tunnel on modified form of the conventional Savonius rotor with the central shaft is reported to have a coefficient of power of 0.32. In this study, modified Savonius rotor without central shaft between the two end plates is tested in an open jet wind tunnel. Investigation is undertaken to study the effect of geometrical parameters on the performance of the rotors in terms of coefficient of Static Torque, coefficient of Torque and coefficient of power. The parameters studied are overlap ratio, blade arc angle, aspect ratio and Reynolds number. The modified Savonius rotor with an overlap ratio of 0.0, blade arc angle of 124° and an aspect ratio of 0.7 has a maximum coefficient of power of 0.21 at a Reynolds number of 1,50,000, which is higher than that of conventional Savonius rotor (0.19). Correlation is developed for a single stage modified Savonius rotor for a range of Reynolds numbers studied.
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high coefficient of Static Torque at certain rotor angles and a negative coefficient of Static Torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in Static Torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of Static Torque, coefficient of Torque and coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have positive coefficient of Static Torque at all the rotor angles. The helical rotors with shaft have lower coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same coefficient of power when compared with the conventional Savonius rotor. Correlation for coefficient of Torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
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experimental investigations on single stage two stage and three stage conventional savonius rotor
International Journal of Energy Research, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The performance of single stage (rotor aspect ratio of 1.0), two stage Savonius rotor with rotor aspect ratios of 1.0 and 2.0 (stage aspect ratios of 0.50 and 1.0) and three stage Savonius rotor with rotor aspect ratios of 1.0 and 3.0 (stage aspect ratios of 0.33 and 1.0) are studied at different Reynolds numbers and compared at the same Reynolds number. The results show that the coefficient of power and the coefficient of Torque increase with the increase in the Reynolds numbers for all the rotors tested. The coefficient of Static Torque is independent of the Reynolds number for all the rotors tested. The performance of two stage and three stage rotors remains the same even after increasing the stage aspect ratio and the rotor aspect ratio by a factor of two and three, respectively. For the same rotor aspect ratio of 1.0, by increasing the number of stages (stage aspect ratio decreases), the performance deteriorates in terms Cp and Ct. However, at the same stage aspect ratio of 1.0 and same Reynolds number, two and three stage rotors show the same performance in terms of coefficient of power and coefficient of Torque. The variation in coefficient of Static Torque is lower for a three stage rotor when compared with the variation of coefficient of Static Torque for two stage or single stage rotor. Copyright © 2008 John Wiley & Sons, Ltd.
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experimental investigations on the effect of overlap ratio and blade edge conditions on the performance of conventional savonius rotor
Wind Engineering, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The Torque of a conventional Savonius rotor is studied experimentally for overlap ratio from 0.10 to 0.70, blade edge condition (flat and round) and the change in Reynolds number. The results indicate that the coefficient of Static Torque improves marginally for round edged rotors for rotor angles up to 45°. The coefficient of Static Torque decreases as the overlap ratio is increased to 0.70 from 0.50 and is independent of the Reynolds numbers studied in the range between 120000 to 200000. Wind tunnel blockage ratio is studied. The power coefficient increases with the increase in the Reynolds number, whereas the coefficient of Static Torque is independent of the Reynolds number in the range studied. The coefficient of power, Torque coefficient and coefficient Static Torque are independent of blockage ratios at a given Reynolds number.
B P Singh - One of the best experts on this subject based on the ideXlab platform.
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Detent Torque from the soft magnetic stator stack of a hybrid stepper motor
Journal of Applied Physics, 2003Co-Authors: Karthikeyan Rajagopal, B P SinghAbstract:The residual magnetism present in the stator stack of a hybrid stepper motor, which will be of the last excited polarity, will develop a detent Torque, similar to the Static Torque of the last excited phase, but with reduced excitation. The predominant component is fundamental. Even though this Torque is the result of the stator excitation, it can be considered as a detent Torque as it is available when the stator excitation is withdrawn. This detent Torque is in addition to the inherent one due to the rotor permanent magnet, and it will be present until the next phase is switched ON. Once the excitation is removed from the second phase, because of the hysteresis the detent Torque will be available, similar to the Static Torque profile for phase 2, but with less excitation. This means because of the hysteresis the detent Torque follows the Static Torque of the phases. The magnitude of this detent Torque will depend upon the level to which the phase was excited. Experiments have been carried out on a 0.5° hybrid stepper motor to study the effects of the excitation on the detent Torque profiles. Harmonic analyses of the measured detent Torque curves had been carried out and it is seen that the fundamental detent Torque increases with the excitation and also follows the respective phases. Therefore, the residual flux density and the coercive force of the soft magnetic material used for the stator stack have to be as small as possible to get rid of this effect. Controlling a hybrid stepper motor by a suitable switching scheme for a given application requires the measured Static Torque profiles of the motor for all the phases at the exact working voltage (or voltages in case of a variable voltage supply) and detent Torque profiles both before and after excitation. Harmonic spectrum of the measured Static and detent Torque profiles have to be accounted for while simulating stepping behavior of the motor, from which an appropriate switching scheme can be arrived at.
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Static Torque profiles of a hybrid stepper motor having relative eccentricity between stator and rotor axes
Journal of Applied Physics, 2003Co-Authors: Karthikeyan Rajagopal, Bhim Singh, B P SinghAbstract:A smooth and controlled driving load for a hybrid stepper motor requires detailed knowledge of the motor’s Static and detent Torque profiles. Uncertainties to measured Torque profiles may be due to rotor/stator concentric misalignment as one possible factor. This article presents the results of a detailed experimental analysis on a stepper motor’s relative eccentricity between the rotor and stator axes. The nonuniform airgap not only introduces a position-dependent fundamental detent Torque along with the conventional fourth harmonic detent Torque, but also changes the Static Torque profile. The sum effect on Static Torque is a changed Torque equilibrium point, dependent both on rotor position and motor phase. Detent Torque harmonic component analysis of a set of 0.5° hybrid stepper motors, with rotor-to-stator eccentricity as the control variable, showed how increased eccentricity exceeding a given limit will cause a loss of stable equilibrium of the detent Torque at each step position.
Karthikeyan Rajagopal - One of the best experts on this subject based on the ideXlab platform.
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Effects of nonuniform airgap on the Torque characteristics of a switched reluctance motor
IEEE Transactions on Magnetics, 2004Co-Authors: N.k. Sheth, Karthikeyan RajagopalAbstract:In this paper, the results of a two-dimensional (2-D) finite element (FE) analysis carried out on a 8/6 switched reluctance motor for studying the effects of nonuniform airgap on the Torque profiles are presented. Results of harmonic analysis of the Static Torque profiles for various nonuniform airgap conditions are presented. Effects of nonuniform airgap produced by relative eccentricity between the stator and rotor axes, concentricity error in the rotor geometry and motor with elliptical shape of rotor are presented. It is observed that nonuniform airgap results in different Static Torque profiles for different phases of the motor. With the increase in the relative eccentricity there is increase in the fundamental, 8/sup th/, 10/sup th/, 14/sup th/, and 15/sup th/ harmonic Torques. It is also observed that for positive concentricity error, motor having elliptical rotor produces more Torque, compared to the motor with concentricity error in one half of the rotor.
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Detent Torque from the soft magnetic stator stack of a hybrid stepper motor
Journal of Applied Physics, 2003Co-Authors: Karthikeyan Rajagopal, B P SinghAbstract:The residual magnetism present in the stator stack of a hybrid stepper motor, which will be of the last excited polarity, will develop a detent Torque, similar to the Static Torque of the last excited phase, but with reduced excitation. The predominant component is fundamental. Even though this Torque is the result of the stator excitation, it can be considered as a detent Torque as it is available when the stator excitation is withdrawn. This detent Torque is in addition to the inherent one due to the rotor permanent magnet, and it will be present until the next phase is switched ON. Once the excitation is removed from the second phase, because of the hysteresis the detent Torque will be available, similar to the Static Torque profile for phase 2, but with less excitation. This means because of the hysteresis the detent Torque follows the Static Torque of the phases. The magnitude of this detent Torque will depend upon the level to which the phase was excited. Experiments have been carried out on a 0.5° hybrid stepper motor to study the effects of the excitation on the detent Torque profiles. Harmonic analyses of the measured detent Torque curves had been carried out and it is seen that the fundamental detent Torque increases with the excitation and also follows the respective phases. Therefore, the residual flux density and the coercive force of the soft magnetic material used for the stator stack have to be as small as possible to get rid of this effect. Controlling a hybrid stepper motor by a suitable switching scheme for a given application requires the measured Static Torque profiles of the motor for all the phases at the exact working voltage (or voltages in case of a variable voltage supply) and detent Torque profiles both before and after excitation. Harmonic spectrum of the measured Static and detent Torque profiles have to be accounted for while simulating stepping behavior of the motor, from which an appropriate switching scheme can be arrived at.
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Static Torque profiles of a hybrid stepper motor having relative eccentricity between stator and rotor axes
Journal of Applied Physics, 2003Co-Authors: Karthikeyan Rajagopal, Bhim Singh, B P SinghAbstract:A smooth and controlled driving load for a hybrid stepper motor requires detailed knowledge of the motor’s Static and detent Torque profiles. Uncertainties to measured Torque profiles may be due to rotor/stator concentric misalignment as one possible factor. This article presents the results of a detailed experimental analysis on a stepper motor’s relative eccentricity between the rotor and stator axes. The nonuniform airgap not only introduces a position-dependent fundamental detent Torque along with the conventional fourth harmonic detent Torque, but also changes the Static Torque profile. The sum effect on Static Torque is a changed Torque equilibrium point, dependent both on rotor position and motor phase. Detent Torque harmonic component analysis of a set of 0.5° hybrid stepper motors, with rotor-to-stator eccentricity as the control variable, showed how increased eccentricity exceeding a given limit will cause a loss of stable equilibrium of the detent Torque at each step position.
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Optimum pole arcs for a switched reluctance motor for higher Torque with reduced ripple
IEEE Transactions on Magnetics, 2003Co-Authors: N.k. Sheth, Karthikeyan RajagopalAbstract:In this paper, the results of a two-dimensional (2-D) finite element (FE) analysis carried out on a 8/6 switched reluctance motor with a view to arrive at the optimum pole arcs for the stator and rotor teeth are presented. The authors have put forward a new method for calculating the average Torque for comparison of Static Torque profiles to identify the optimum one. In this new method, 15/spl deg/ of the Static Torque profile, where the developed Torque is nearly constant is considered for calculating the average Torque. Operating the motor in this range instead of the first quarter cycle of the Static Torque profile will ensure higher average Torque with minimum ripple. This average Torque is considered as the parameter for comparison of different Torque profiles of various pole arcs for the stator and rotor. It is observed that the geometry with the existing stator pole arc of 20.2/spl deg/ and a changed rotor pole arc of 30/spl deg/, instead of the existing 23.5/spl deg/ will be the optimum for this motor, as it gives the highest average Torque with the minimum ripple.
M A Kamoji - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of Static Torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the coefficient of Static Torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides positive coefficient of Static Torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The coefficient of Static Torque variations decrease with the increase in the number of stages. However, the coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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experimental investigations on single stage modified savonius rotor
Applied Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius or modified forms of the conventional Savonius rotors are being investigated in an effort to improve the coefficient of power and to obtain uniform coefficient of Static Torque. To achieve these objectives, the rotors are being studied with and without central shaft between the end plates. Tests in a closed jet wind tunnel on modified form of the conventional Savonius rotor with the central shaft is reported to have a coefficient of power of 0.32. In this study, modified Savonius rotor without central shaft between the two end plates is tested in an open jet wind tunnel. Investigation is undertaken to study the effect of geometrical parameters on the performance of the rotors in terms of coefficient of Static Torque, coefficient of Torque and coefficient of power. The parameters studied are overlap ratio, blade arc angle, aspect ratio and Reynolds number. The modified Savonius rotor with an overlap ratio of 0.0, blade arc angle of 124° and an aspect ratio of 0.7 has a maximum coefficient of power of 0.21 at a Reynolds number of 1,50,000, which is higher than that of conventional Savonius rotor (0.19). Correlation is developed for a single stage modified Savonius rotor for a range of Reynolds numbers studied.
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high coefficient of Static Torque at certain rotor angles and a negative coefficient of Static Torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in Static Torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of Static Torque, coefficient of Torque and coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have positive coefficient of Static Torque at all the rotor angles. The helical rotors with shaft have lower coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same coefficient of power when compared with the conventional Savonius rotor. Correlation for coefficient of Torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
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experimental investigations on single stage two stage and three stage conventional savonius rotor
International Journal of Energy Research, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The performance of single stage (rotor aspect ratio of 1.0), two stage Savonius rotor with rotor aspect ratios of 1.0 and 2.0 (stage aspect ratios of 0.50 and 1.0) and three stage Savonius rotor with rotor aspect ratios of 1.0 and 3.0 (stage aspect ratios of 0.33 and 1.0) are studied at different Reynolds numbers and compared at the same Reynolds number. The results show that the coefficient of power and the coefficient of Torque increase with the increase in the Reynolds numbers for all the rotors tested. The coefficient of Static Torque is independent of the Reynolds number for all the rotors tested. The performance of two stage and three stage rotors remains the same even after increasing the stage aspect ratio and the rotor aspect ratio by a factor of two and three, respectively. For the same rotor aspect ratio of 1.0, by increasing the number of stages (stage aspect ratio decreases), the performance deteriorates in terms Cp and Ct. However, at the same stage aspect ratio of 1.0 and same Reynolds number, two and three stage rotors show the same performance in terms of coefficient of power and coefficient of Torque. The variation in coefficient of Static Torque is lower for a three stage rotor when compared with the variation of coefficient of Static Torque for two stage or single stage rotor. Copyright © 2008 John Wiley & Sons, Ltd.
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experimental investigations on the effect of overlap ratio and blade edge conditions on the performance of conventional savonius rotor
Wind Engineering, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The Torque of a conventional Savonius rotor is studied experimentally for overlap ratio from 0.10 to 0.70, blade edge condition (flat and round) and the change in Reynolds number. The results indicate that the coefficient of Static Torque improves marginally for round edged rotors for rotor angles up to 45°. The coefficient of Static Torque decreases as the overlap ratio is increased to 0.70 from 0.50 and is independent of the Reynolds numbers studied in the range between 120000 to 200000. Wind tunnel blockage ratio is studied. The power coefficient increases with the increase in the Reynolds number, whereas the coefficient of Static Torque is independent of the Reynolds number in the range studied. The coefficient of power, Torque coefficient and coefficient Static Torque are independent of blockage ratios at a given Reynolds number.
Shireesh B. Kedare - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of Static Torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the coefficient of Static Torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides positive coefficient of Static Torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The coefficient of Static Torque variations decrease with the increase in the number of stages. However, the coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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experimental investigations on single stage modified savonius rotor
Applied Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius or modified forms of the conventional Savonius rotors are being investigated in an effort to improve the coefficient of power and to obtain uniform coefficient of Static Torque. To achieve these objectives, the rotors are being studied with and without central shaft between the end plates. Tests in a closed jet wind tunnel on modified form of the conventional Savonius rotor with the central shaft is reported to have a coefficient of power of 0.32. In this study, modified Savonius rotor without central shaft between the two end plates is tested in an open jet wind tunnel. Investigation is undertaken to study the effect of geometrical parameters on the performance of the rotors in terms of coefficient of Static Torque, coefficient of Torque and coefficient of power. The parameters studied are overlap ratio, blade arc angle, aspect ratio and Reynolds number. The modified Savonius rotor with an overlap ratio of 0.0, blade arc angle of 124° and an aspect ratio of 0.7 has a maximum coefficient of power of 0.21 at a Reynolds number of 1,50,000, which is higher than that of conventional Savonius rotor (0.19). Correlation is developed for a single stage modified Savonius rotor for a range of Reynolds numbers studied.
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high coefficient of Static Torque at certain rotor angles and a negative coefficient of Static Torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in Static Torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of Static Torque, coefficient of Torque and coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have positive coefficient of Static Torque at all the rotor angles. The helical rotors with shaft have lower coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same coefficient of power when compared with the conventional Savonius rotor. Correlation for coefficient of Torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
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experimental investigations on single stage two stage and three stage conventional savonius rotor
International Journal of Energy Research, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The performance of single stage (rotor aspect ratio of 1.0), two stage Savonius rotor with rotor aspect ratios of 1.0 and 2.0 (stage aspect ratios of 0.50 and 1.0) and three stage Savonius rotor with rotor aspect ratios of 1.0 and 3.0 (stage aspect ratios of 0.33 and 1.0) are studied at different Reynolds numbers and compared at the same Reynolds number. The results show that the coefficient of power and the coefficient of Torque increase with the increase in the Reynolds numbers for all the rotors tested. The coefficient of Static Torque is independent of the Reynolds number for all the rotors tested. The performance of two stage and three stage rotors remains the same even after increasing the stage aspect ratio and the rotor aspect ratio by a factor of two and three, respectively. For the same rotor aspect ratio of 1.0, by increasing the number of stages (stage aspect ratio decreases), the performance deteriorates in terms Cp and Ct. However, at the same stage aspect ratio of 1.0 and same Reynolds number, two and three stage rotors show the same performance in terms of coefficient of power and coefficient of Torque. The variation in coefficient of Static Torque is lower for a three stage rotor when compared with the variation of coefficient of Static Torque for two stage or single stage rotor. Copyright © 2008 John Wiley & Sons, Ltd.
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experimental investigations on the effect of overlap ratio and blade edge conditions on the performance of conventional savonius rotor
Wind Engineering, 2008Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:The Torque of a conventional Savonius rotor is studied experimentally for overlap ratio from 0.10 to 0.70, blade edge condition (flat and round) and the change in Reynolds number. The results indicate that the coefficient of Static Torque improves marginally for round edged rotors for rotor angles up to 45°. The coefficient of Static Torque decreases as the overlap ratio is increased to 0.70 from 0.50 and is independent of the Reynolds numbers studied in the range between 120000 to 200000. Wind tunnel blockage ratio is studied. The power coefficient increases with the increase in the Reynolds number, whereas the coefficient of Static Torque is independent of the Reynolds number in the range studied. The coefficient of power, Torque coefficient and coefficient Static Torque are independent of blockage ratios at a given Reynolds number.