What are parts of a wind tunnel?

A wind tunnel typically consists of several key components: the test section, where the model or object being tested is placed; the contraction section, which narrows the airflow to increase its speed before entering the test section; and the diffuser section, which helps to gradually expand the airflow after it exits the test section. Additionally, there are fans or blowers for generating airflow, and measurement instruments to assess the aerodynamic forces acting on the test model. Some wind tunnels also include control systems for regulating airflow and ensuring accurate testing conditions.