Experimental Studies on Savonius and Bach Type Rotors

In this work, experiments have been performed on different geometries and shapes of Savonius rotor and the most suited parameters have been found. The blade shape factor (p/q) for Bach type blades has been taken 0.4 and 0.2 by fixing the blade arc angle 124°. Experiments have been performed on them with different overlap ratios, from 10%, 15% and 25% and also use of concentrating arrangements has been made. Conventional Savonius rotors (single-stage and double-stage) have also been tested with end plates and without overlap variation. The comparison has been made among these rotors for coefficient of power and coefficient of torque. The effect of concentrator is also being studied to improve the performance parameters. Experimentation on the rotors reported that Bach type rotor having p/q=0.4 shows a maximum value of Cp and of Ct at 15%overlap with concentrator. The single-stage Bach type rotors of p/q=0.2 also showed values of the performance parameters at zero and 25% overlap variation. The double-stage Bach rotors having p/q =0.2 also showed the performance level at zero and 15% overlap variation.