The Invelox system is an innovative technique to harness wind energy. It works by speeding up and guiding wind through a funnel-shaped construction, which makes windmills more efficient. This system directs wind through a number of concentrators, ducts, and diffusers, making it much faster before it hits the turbine blades. This is different from traditional wind turbines, which use big, open blades to collect wind energy. Smaller, ground-based windmills can be used with this design, which has less of an effect on the environment and looks better while still being able to collect energy from winds at slower speeds and in more places. In our latest try, based on the reference paper entitled “ INVELOX: Description of a new concept in wind power and its performance evaluation “, this newly proposed concept is simulated by means of ANSYS Fluent.

• Reference [1]: Allaei, Daryoush, and Yiannis Andreopoulos. “INVELOX: Description of a new concept in wind power and its performance evaluation.” Energy69 (2014): 336-344.

Figure 1: Invelox system in Wind Power

Simulation Process

The simulation used a pressure-based solver with 3D Reynolds-Averaged Navier-Stokes (RANS) equations, a workable k-epsilon turbulence model, and better wall treatment to correctly predict. For the momentum and turbulence equations, a steady-state method with second-order upwind discretization schemes was used to make sure that the numbers would stay stable and the solutions would be correct. For the boundary conditions, a steady inlet speed of 6.7 m/s (15 mph) with 5% turbulence intensity was set, and at the diffuser exit, a pressure outlet condition was put in place. The INVELOX-12-02 design is an omnidirectional double-nested cone that was scaled up to 18 meters in height to fit a 1.8-meter-diameter wind turbine at the Venturi section. It was carefully modeled, paying special attention to geometric details like the intake configuration and partition baffles that are positioned to capture the most wind from any direction.

Figure 2: Computational domains used in ANSYS

Post-processing

Based on the CFD modeling results, we can see how the INVELOX system works as a wind energy concentration device. The velocity contours show that the flow speeds up a lot through the system. The inlet speeds are around 0.4 to 0.6 m/s (blue regions at entry), but they reach over 1.85 m/s at the exit venturi section, which is a rise in velocity of about 3 to 4 times. This speeding up is made possible by an innovative omnidirectional intake design that successfully captures and funnels ambient wind from every angle, along with the cross-sectional area decreasing along the flow path. The pressure distribution image shows that there is a big difference in pressure, with higher pressure areas (orange-red, ~2.93e-01 Pa) at the intake and lower pressure areas (blue, ~-2.38e-02 Pa) at the venturi section. By putting a fan at the venturi section, this difference in pressure can be used to take advantage of the available energy and speed up the flow of air.

Figure 3: Distribution of a) velocity b) pressure around the Invelox wind power system