Design obstruction of the air inside the model to generate high-turbulence air before entering the wind tunnel using COMSOL Multiphysics simulation

The objective of this research is to reduce the turbulent intensity and velocity of the air by designing the inlet (300 mm x 300 mm x 300 mm), the internal structure consists of the obstacle to the air by using computational fluid dynamics methods and the COMSOL Multiphysics program with the turbulence k-ɛ model, this research design obstacle is divided into three parts: shape, number, and diameter of the obstacle to the air. Design of obstacle in a rectangular and circular, number of pipes 12 and 14 pipes, diameters 20- 40 mm. The experimental results of the structure causing the turbulence at the obstacle to the air suitable design is a rectangular shape, 14 pipes, and 40 mm in diameter. In conclusion, the turbulence intensity is in the range of 0.20-0.43 which results in high turbulence intensity and uniformity.