The Savonius wind turbine stands out in the ever-changing renewable energy field. The vertical-axis Savonius turbine has practical and visual benefits over its conventional equivalents. Its stylish, curving blades efficiently harness wind power, indicating the delicate balance between human innovation and environmental responsibility. The Savonius turbine implies innovation and a greener, more sustainable future for future generations as we navigate sustainable energy generation.

This led us to come up with the idea of simulating Savonius wind turbine, the well-known drag-based vertical axis wind turbine worldwide. In this study, the paper entitled “PERFORMANCE CHARACTERISTICS OF VERTICAL-AXIS OFF-SHORE SAVONIUS WIND AND SAVONIUS HYDROKINETIC TURBINES” is selected as the base guidance.

Figure 1: Schematic view of Savonius turbine [1]

Simulation Process

Savonius blades with a diameter of nearly 200mm are designed using design modeler software. It consists of a stationary and rotating domain. It is essential to perform an appropriate grid near the interface boundary and the blades. Later, Sliding mesh is employed to transmit values of cells into the rotating zone. This feature is also known as Mesh Motion. In addition, the K-omega SST turbulence model facilitates us in capturing fluid behavior near the blades and also in the wake areas behind. Time step size can also plays a prominent role in the simulation. Setting appropriate Reference Values has great importance to calculate correct Torque coefficient.

Figure 2: Boundary layer on Savonius blades

Post-processing

Many important conclusions follow from modeling the Savonius wind turbine and examining the resultant contours together with the torque coefficient plot. The contours show the complex flow patterns around the turbine blades, hence stressing high and low-pressure distribution zones. These lines provide helpful graphic indications about the turbine’s performance and efficiency. The turbine’s rotational performance under various wind conditions can be statistically informed by the torque coefficient plot meantime. This image gives important details on the turbine’s capacity to effectively convert wind energy into rotational motion. Since it takes some time to get working condition, the plot is only taken out for the fourth round and following. The torque coefficient is computed, by the way, using the equation:

Figure 3: Torque coefficient as a function of round for Savinous wind turbine

The velocity contour visualization reveals complex wake characteristics behind the Savonius rotor, with velocities ranging from 0.005 to 1.634 m/s in the stationary reference frame. The immediate wake region shows distinct vortex shedding patterns, characterized by alternating high and low-velocity zones. The circular interface boundary clearly captures the interaction between the rotating domain and the stationary field, where maximum velocity gradients occur near the blade tips. This wake structure, extending approximately 3-4 rotor diameters downstream, demonstrates the typical momentum deficit characteristic of drag-based vertical axis wind turbines.

Figure 4: Wake region behing the Savonius wind turbine given in the velocity pattern contour