Experimental investigations on single stage, two stage and three stage conventional Savonius rotor

Abstract

SUMMARYThe 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.

Effect of blade installation angle on power efficiency of resistance type VAWT by CFD study

“…In accordance with the simulation of Savonius wind turbine [13][14][15][16][17][18][19][20][21][22], it could draw lessons from the effective digging to the ''external potentiality'' for improving the power efficiency. In fact, the ''inner potential'' for improving power efficiency is still need to dig.…”

Computational assessment of the influence of the overlap ratio on the power characteristics of a Classical Savonius wind turbine

“…In order to investigate the in uence of the overlap ratio on the power characteristics of a Classical Savonius wind turbine, full scale threedimensional (3D) simulations were carried out together with a series of two-dimensional (2D) simulations. Dimensions of a numerical model directly correspond to a low aspect ratio turbine examined experimentally by Kamoji et al [5,6]. In this way, it was possible to verify obtained results and check the in uence of di erent task con gurations (2D or 3D solutions) on the prediction quality.…”

“…For the purposes of these investigations the model was composed of two domains ( Figure 3). The rst one (rotating) comprised the wind turbine blades and endplates and the second (stationary), simulated the wind tunnel with dimensions in accordance with the experimental test stand data [5,6]. The rotating domain radius was twice as big as the rotor radius.…”

“…This velocity corresponds to Re = 120 000. Additionally, low turbulence intensity (1%) was set as in [6]. At the outlet atmospheric pressure was imposed ( Pa).…”

Numerical Investigation on the Flow Noise Characteristics of the Hybrid Vertical-axis Wind Turbine

“…이 외에도, Fujisawa, [2] Akwa et al, [3] Mohamed et al, [4] Kamoji et al [5] 와 같은 많은 연구들이 수행되고 있다. 또한, Kim et al [6,7] 은 김상현, 정철웅 [8] 이 일정한 풍속에서의 초기구동에 관한 실험 적･수치적 연구를 수행한 바 있으며, Rossetti et al, [9] Beri et al [10] 와 같은 연구도 이루어진바 있다.…”