Vertical wind tunnel
A vertical wind tunnel ( VWT ) is a wind tunnel that, in contrast to a traditional wind tunnel for aerodynamic or aeroacoustic measurements, has a vertical measuring section (flight chamber). The first vertical wind tunnels were used as so-called spiral towers in the field of aviation research. Today vertical wind tunnels are mainly used in the sport and leisure sector as training facilities for parachutists . Starting from parachuting, so-called body flying or indoor skydiving has developed through the technical development of vertical wind tunnels since the 1960s .
Vertical wind tunnels enable human flight without aids (airplane, parachute) solely through the force of the vertically generated air flow. The air in the vertical wind tunnel reaches an average speed of 180 to 200 km / h. This corresponds to the average speed of fall of a human body in free fall in the prone position. Vertical wind tunnels are often referred to as indoor skydiving , body flying hall or free fall simulator .
Body flying
Bodyflying literally means “body flying” and stands for the art of moving the human body in a controlled manner in the air. Originally coming from parachuting, bodyflying stands for a training opportunity for skydivers, but increasingly also for an independent sport: flying a human body in a vertical wind tunnel.
In the vertical wind tunnel, the air flow speed corresponds to the free fall speed of the human body. Modern vertical wind tunnel systems can individually adjust the air speed depending on the body weight of the person flying. In body flying, the human body is moved relative to the wind. By appropriately tensing the body and using hands and feet as oars, the force of the air flow can be influenced and the body can be moved in different directions. Basic bodyflying figures include floating up and down, sideways movement in all four horizontal directions, and right and left turns.
Vertical wind tunnel systems
Classic vertical wind tunnels consist of one or more fans to generate the air flow, diffusers for the most even and turbulence-free flow, a nozzle to accelerate the air flow and the actual flight chamber. The flow in the flight chamber should be as uniform, parallel, and low in turbulence and noise as possible. There are two basic systems for vertical wind tunnels, which differ according to their air flow system:
- Closed vertical wind tunnels that recirculate the air in an annular air duct (recirculator) , e.g. B. Indoor Skydiving Bottrop, Germany.
- Open vertical wind tunnels that function according to a suction and discharge principle (open flow) , e.g. B. SkyVenture Arizona, Eloy, USA.
In addition, the term vertical wind tunnel has established itself for free fall simulators that do not correspond to the classic construction of a vertical wind tunnel, e.g. B. Bodyflying facility, Rümlang, Switzerland.
Closed vertical wind tunnels have a ring-shaped air flow (so-called Göttingen design ). Here the air flow taken up by the diffuser after the flight chamber is fed back to the blower or blowers. The advantage of the closed system is the independence from wind and weather. The system can be operated all year round in any weather, especially regardless of the outside temperature. Furthermore, closed systems usually convince with their significantly lower sound level and their energy efficiency. The air flow in closed systems is less turbulent than in other free fall simulators. The first, closed vertical wind tunnel in continental Europe according to the Göttingen design was opened in April 2009 in Bottrop, Germany and offers parachutists and laypeople the opportunity to experience the feeling of free flight all year round, free from fear of heights.
Open vertical wind tunnels have an air duct that is open on both sides. In these systems, air is sucked in from the environment, flows through the flight chamber and is expelled back into the open at the upper end of the channel. Due to the open construction, these systems are prone to weather. Wind, rain, extreme outside temperatures, but also dust and dirt can affect flight operations and sometimes require the facility to be temporarily closed.
Other free fall simulators usually consist of a grid-spanned propeller that generates a vertical air flow that is open on all sides. Since there is a lack of a closed flight chamber in these systems, there is a risk of falling out or involuntary flying out of the air stream, the safety net is surrounded by a cushion edge. This form of vertical wind tunnel can be found as a stationary as well as a transportable system. Since the speed of the air flow in these systems is lower than in classic vertical wind tunnels, wearing wide flight suits for additional lift is the rule. Furthermore, the air flow is more turbulent due to the lack of air guidance.
safety
Flying in the vertical wind tunnel is harmless and enables people with a fear of heights to experience the feeling of free fall beyond a skydiving machine. In the vertical wind tunnel, the human body flies, depending on ability, only a few centimeters to meters above a safe safety net. The air speed is adjusted to the individual ability of the flyer and usually varies between 180 and 200 km / h.
history
The first vertical wind tunnels were designed and built for aeronautical research in the 1930s. The building of one of the first spiral towers in the Berlin district of Adlershof can still be viewed today. Construction of the first vertical wind tunnel with sufficient air speed for human flight began in the United States in the 1940s at Wright Patterson Air Force Base, Dayton, Ohio. The airflow was propelled by a four-blade propeller, 16 feet (4.88 m) in diameter, via a 1,000 horsepower electric motor. The flight chamber had a diameter of 12 feet (3.66 m) and was used to study spin, especially of driverless, "staggering" aircraft and small parachutes. In 1964, a parachutist and then an employee of the Apollo program dared the first human flight in this vertical wind tunnel. In the early 1970s, the American Forces Precision Freefall Team, The Golden Knights , began training regularly at Wright Patterson Air Force Base.
In 1979 the first patent for a free fall simulator that does not correspond to the classic design of a vertical wind tunnel was registered by Jean St. Germain in Canada. The patent is for “levitationarium for air flotation of humans”. The first commercial free fall simulator opened in Las Vegas, USA in 1982.
The increased construction of classic open and closed vertical wind tunnel systems for a wide audience only began in the late 1990s with the opening of an open-flow vertical wind tunnel in Orlando, USA, in 1998. The world's largest indoor wind tunnel with a diameter of 10 m has been in operation since November 2019 in operation in Abu Dhabi. The largest German wind tunnel with a diameter of 5.2 m was opened in July 2017 in Schönefeld near Berlin .
Web links
Individual evidence
- ↑ Kyra Poh and Maja Kuczyńska aerial dance in the world's largest wind tunnel. Red Bull, December 13, 2019, accessed June 16, 2020 .
- ↑ Largest wind tunnel in Germany opened. Märkische Allgemeine, July 17, 2017, accessed on June 16, 2020 .