The flow of atmospheric air over obstacles such as isolated islands or mountains sometimes gives rise to von Kármán vortex streets. When a cloud layer is present at the corresponding altitude, streets become visible. Such cloud layer vortex lanes have been photographed from satellites.[2]​ The vortex lane can reach more than 400 km from the obstacle and the diameter of the vortices is typically 20-40 km.[3]​.

The periodic forces established in this way can be very undesirable and it is therefore important to consider the potential effects of vortex production in the design of various types of structures,[4]​ such as periscopes, submarines or industrial chimneys, especially for concrete cooling towers, particularly when built in groups. In fact, this phenomenon caused some of the chimneys of the Ferrybridge thermal power station to collapse,[5]​[6]​[7]​ in northern England, in 1965 during strong winds.

In low turbulence, tall buildings can produce a Kármán street, as long as the structure is uniform throughout its height. In urban areas where there are many other tall structures nearby, the turbulence produced by them prevents the formation of coherent vortices.[8] The periodic crosswind forces established by vortices along the sides of objects can be highly undesirable, so it is important for engineers to take into account the possible effects of vortex shedding when designing a wide range of structures.

When considering a long circular cylinder, the frequency of vortex production is determined according to the following empirical relationship "Phenomenology (science)"):

This formula is generally correct for ranges 250 < Re < 2 × 10. The dimensionless parameter fd/V is known as the Strouhal number and is named after the Czech physicist, Vincenc Strouhal (1850-1922), who first investigated the constant humming or singing of telegraph cables in 1878.

Some studies have shown that when flying, insects such as bees take energy from the vortices around them, because by generating these drags "Drag (physics)") they can improve their speed.[9]​.

• - Wikimedia Commons hosts a multimedia gallery on Von Kármán vortex street.

• - Animation of a von Kármán vortex street and explanation.

• - Instabilities of vortex streets and Strouhal.

• - How insects fly.

The flow of atmospheric air over obstacles such as isolated islands or mountains sometimes gives rise to von Kármán vortex streets. When a cloud layer is present at the corresponding altitude, streets become visible. Such cloud layer vortex lanes have been photographed from satellites.[2]​ The vortex lane can reach more than 400 km from the obstacle and the diameter of the vortices is typically 20-40 km.[3]​.

The periodic forces established in this way can be very undesirable and it is therefore important to consider the potential effects of vortex production in the design of various types of structures,[4]​ such as periscopes, submarines or industrial chimneys, especially for concrete cooling towers, particularly when built in groups. In fact, this phenomenon caused some of the chimneys of the Ferrybridge thermal power station to collapse,[5]​[6]​[7]​ in northern England, in 1965 during strong winds.

In low turbulence, tall buildings can produce a Kármán street, as long as the structure is uniform throughout its height. In urban areas where there are many other tall structures nearby, the turbulence produced by them prevents the formation of coherent vortices.[8] The periodic crosswind forces established by vortices along the sides of objects can be highly undesirable, so it is important for engineers to take into account the possible effects of vortex shedding when designing a wide range of structures.

When considering a long circular cylinder, the frequency of vortex production is determined according to the following empirical relationship "Phenomenology (science)"):

This formula is generally correct for ranges 250 < Re < 2 × 10. The dimensionless parameter fd/V is known as the Strouhal number and is named after the Czech physicist, Vincenc Strouhal (1850-1922), who first investigated the constant humming or singing of telegraph cables in 1878.

Some studies have shown that when flying, insects such as bees take energy from the vortices around them, because by generating these drags "Drag (physics)") they can improve their speed.[9]​.

• - Wikimedia Commons hosts a multimedia gallery on Von Kármán vortex street.

• - Animation of a von Kármán vortex street and explanation.

• - Instabilities of vortex streets and Strouhal.

• - How insects fly.