The strongest wind tunnels in the world

Wind tunnels have become a mainstay in the aerospace industry, helping to test the aerodynamics of countless aircraft and rockets.

Top 5 most powerful wind tunnels in the world today, according to Interesting Engineering

A wind tunnel is a machine that simulates the flow of air through objects. The system always consists of a long narrow pipe where the air flow is introduced using various methods such as powerful fans. The model or object to be tested is placed inside the pipe. The air flow will be controlled to study its effect on the object under different conditions such as changing wind speeds. First developed in the late 19th century, wind tunnels are now widely used in many industries. For example, wind tunnels used in the vehicle manufacturing industry test the aerodynamics of cars, race cars, trucks and other vehicles.

In civil engineering, wind tunnels test the structural soundness of buildings and infrastructure projects. They also help optimize aircraft and rocket designs for safer and more efficient flight.

1. JF-22

The JF-22 wind tunnel can simulate the environment when the spacecraft reenters the atmosphere. (Photo: CCTV)

JF-22 is the world's most powerful hypersonic wind tunnel. Built at the Institute of Mechanical Engineering of the Chinese Academy of Sciences (IMCAS) north of Beijing, the JF-22 can reach speeds of up to Mach 30 (37,044 km/h or 10.3 km/s).

The JF-22 does not use fans because fans cannot produce such high-speed airflow. Instead, this wind tunnel uses timed explosions to produce shock waves that reflect each other and converge at a point inside the 4 m diameter and 167 m long pipe. JF-22 can provide a capacity of 15 gigawatts (GW), equal to 70% of the capacity of the Three Gorges Dam, the world's largest hydroelectric dam in Yichang, China.

2. JF-12

The JF-12 is often considered the predecessor of the JF-22, which is an open-circuit wind tunnel. Like the latest JF-22 wind tunnel, the JF-12 uses shock waves to create flight conditions from Mach 5 (6,174 km/h) to Mach 9 (11,174 km/h), at altitudes from 25,000 m up to 50,000 m.

Built by IMCAS's Institute of Mechanical Engineering between 2008 and 2012, the JF-12 was important in the development of China's DF-ZF hypersonic glide vehicle (HGV), according to a report from the Aerospace Research Institute. Ttung Quoc headquarters. JF-12 is still operating in parallel with JF-22.

3. T-117 TsAGI supersonic wind tunnel

T-117 TsAGI wind tunnel. (Photo: TsAGI).

The T-117 TsAGI is a large supersonic wind tunnel built at the Central Institute of Hydrodynamics in Moscow, Russia, in the 1970s. The system operates according to the blowdown rule, in which high-pressure gas quickly dissipates. launched into the remaining area in the wind tunnel to create a stream of air. Two separate electric furnaces, removable depending on the experiment, heat the gas stream.

One furnace uses two arcs to deliver a maximum output of 25 megawatts, while the other uses a single arc to deliver a maximum output of 2.5 megawatts. Air in furnaces is heated between two electrodes aligned along the same axis, producing an electric arc. The electric arc then rotates thanks to the magnetic field, warming the air passing between the electrodes.

In this way, the T-117 TsAGI can simulate the high temperatures that hypersonic vehicles encounter in flight, while generating test speeds ranging from Mach 5 (6,174 km/h) to Mach 10 (12,348 km/h) H). In 2018, the T-117 TsAGI was used to test the hypersonic flight mode of the Federation spacecraft, a project of the Russian space agency Roscosmos to replace the Soyuz spacecraft in various low-orbit missions. Earth and Moon.

4. Hypersonic Tunnel Facility (HTF)

The Hypersonic Tunnel Facility (HTF) is located at NASA's Neil Armstrong Test Facility, within the Glenn Research Center in Sandusky, Ohio. Originally built to test nuclear thermal rocket nozzles in the Nuclear Engine Applications on Rocket Vehicles (NERVA) program, the facility now specializes in testing large-scale hypersonic aspirated propulsion systems at high speeds. altitude from Mach 5 (6,174 km/h) to Mach 7 (8,644 km/h), simulating actual altitude (36,500 m).

The testing area in the HTF is adjustable from 3.05 m to 4.27 m. There, a graphite-core thermoelectric furnace heats nitrogen gas, which then mixes it with room-temperature oxygen and nitrogen to create pollution-free artificial air in true proportions. The temperature of the artificial air is controlled to the specific requirements for the test. HTF can operate every 5 minutes, depending on operating conditions.

5. Unitary Plan Wind Tunnel (UPWT)

Space Launch System rocket model tested in the subsonic wind tunnel of the UPWT system. (Photo: NASA).

Unitary Plan (UPWT) is one of the largest operating wind tunnels in the world. The facility is located at NASA's Ames Research Center in Moffet Field, California. Since its completion in 1955, the Unitary Plan wind tunnel (UPWT) has helped test both conventional aircraft (commercial and military) and spacecraft (like NASA's retired space shuttle). This tunnel plays a key role in the development of Boeing's fleet of aircraft as well as the F-111 fighter jet and B-1 Lancer bomber.

UPWT includes 3 closed circuit wind tunnels: 3.4 x 3.4 m subsonic wind tunnel (TWT), 2.7 x 2.1 m supersonic wind tunnel and 2.4 x supersonic wind tunnel 2.1 m. The final wind tunnel can reach speeds of Mach 3.5 (4,321 m). It all operates thanks to 4 electromagnetic motors with wound rotors with a capacity of 65,000 horsepower, operating at 7,200 volts.