Non-uniform Airflow Analysis of a Greenhouse Extractor Axial with Conical Diffusers using CFD Simulation

Interest in wind energy use has increased in recent years, specifically in the study field of protected agriculture. To harness residual wind energy produced in an air exhaust system, a wind energy recovery system could be installed using a horizontal axis wind turbine, designed according to airflow conditions at the system outlet. For this reason, airstream in a greenhouse exhaust system was analyzed, wherefore a set of extractors with different number and blades wide, air attack angle, angular velocity and geometry exhaust duct were designed. Subsequently, some simulations were performed by Computational Fluid Dynamics based on different boundary conditions and according two pipeline geometric configurations: with simple and double conical diffuser. 3D model resolution was based on numerically solving the Navier-Stokes equations by means of a finite volume discretization method. With this information 36 2D images of velocity contours and another 36 in 3D of the output airflow streamlines were obtained, also speed and power curves were constructed with respect to geometric model and exhaust system. Moreover, air flow, torque, and power of exhaust system were determined. Finally, opening and flow angle values inside and outside the exhaust system airstream were estimated. By implementing a waste wind energy recovery system at a greenhouse extraction system outlet, will be possible to improve the use of generated airstream, which in most cases is expelled to the outside.