3D Printing & Wind Energy: Refining the Elliptical Savonius Turbine

In the recently published ‘Experimental Study of the Performance of the Elliptical Savonius Turbine and New Design for Blade Shape Using A 3D Printing Technology,’ researchers from Malaysia and Iraq examine the efficiency of the Savonius wind turbine.

Concerned with the geometry of the blade shape here, the researchers point out that ‘a lot of research has been done on developing and improving this parameter,’ and in this study they strive to create a new design with better performance. The researchers remind us that wind energy is one of the most important elements in green technology today—especially due to the affordability factor and its plentiful nature.

Flowchart of study

Designed in 1925 by an engineer named Savonius, the turbine of the same name is currently simplistic and somewhat inefficient. For this study, the goal was to create a turbine blade that would increase positive torque, with dimensions adjusted in a manner similar to those of the cross-section used in the experimental work.

2D simulation domains

“The rotor domain (the Savonius turbine model) is placed at an appropriate distance from the stationary domain input. The boundary conditions for the 2D unstable simulation are established at the wind speed of the system at a constant value (U=6 m/s), while at the stationary domain outputs setup the pressure is equal to the atmospheric pressure,” state the researchers.

“The domain aspects are assumed to be symmetry walls. For the numerical 2D unsteady simulation of the disorder, four types of disturbance type are selected and tested to determine the type of disturbance that is most appropriate in this study, which are Standard k-ω, (SST) k-ω, Standard k-ϵ and Realizable k-ϵ. At U=6 m/s, 2D simulations are performed on the conventional elliptical Savonius turbine with an interference ratio of 0.15.”

The researchers created experiments to test their new elliptical Savonius rotary model, with dimensions of the wind tunnel at the total length of 610cm and the air intake area at 120m, 120cm. The sample testing area was 125 cm long with a test section of 40cm x 40 cm.

A- Schematic diagram of the wind tunnel, B-Test section

Wind speed values were controlled manually.

“To compare the performance efficiency of a new Savonius turbine for the experimental tests, the maximum torque coefficient and the power coefficient are calculated for each wind speed and versus with the tip speed ratio (TSR) as shown in Fig. 12 and Fig. 13 respectively, and comparison of the power coefficient of a new model with the classical model at (U=6 m/s) as shown in Fig. 14,” stated the researchers.

Comparison of the torque coefficient of a new model

Comparison of the power coefficient of a new model

Comparison of the power coefficient of a new model with classical model

3D printing and wind are often associated through research, development, and experimentation of different blades and turbines, from those created by student groups to researchers creating low-pressure blades, and improving gas turbines too. What do you think of this news? Let us know your thoughts; join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Velocity contours- elliptical Savonius rotor

Pressure contours- The elliptical Savonius rotor