3.1. Flow visualization
When doing flow visualization, we come to understand better the patterns of horizontal flows. When airflow from outside goes through the turbine ventilators, the flow is divided into two streams on the horizontal plane. The flow on the left goes in the same direction with the rotation of the turbine and naturally becomes the force to push on the rotation of the turbine. The left-hand side flow then flows along the turbine ventilator to the wake region. The direction of the flow on the right is contrary to that of the rotating turbine, and thus becomes the defected field of airflow that blocks the turbine from rotating.