One of the numerous German „Wunderwaffen” („wonder weapons”) was the obscure Windkanone, or Wind Cannon. Developed in Stuttgart, the Wind Cannon was essentially an anti-aircraft gun that used no solid ammunition. A mixture of hydrogen and oxygen would be ignited, creating a massive air blast that would fly out of an upward-pointing pipe, hopefully hitting and destabilizing low-flying Allied planes, such as ones on a strafing or rocket run. Early tests suggested that the air blast could cause some damage to an unarmored ground target, but the weapon's single actual deployment failed to shoot down any planes.
Nazi Germany also experimented with another wind-based weapon under the authority of Nazi chief architect Albert Speer, who was also Minister of Armaments at the time. The „vortex cannon” was supposed to launch a special mortar round into the air, which in turn would create a small whirlwind powerful enough to rip the wings off a plane. As you might expect, this project never got anywhere, either – but the idea lived on. The United States considered vortex- and wind machines for crowd and mob control in the early 70s, once again without any results, and similar ideas have surfaced several times since.