Everyone who swam in his life will approve, that strokes underwater require a lot of strength. The amount of strength needed rises the faster you swim. If you want to dive very fast the strength required is at the top. The resistance of water ist a thousand times bigger than the one of air.

This problem is also known by naval architects. To minimize the contact points with the water and therefore to go faster different types of hulls were introduced. Furthermore to enhance the velocity naval architects mounted strong motors to the ships. The main goal is to reduce the contact points between the ship and water as listed above.

If an object moves underwater it’s in permanent contact with the liquid. Therefore the cinetic energy, which is responsible for the forward movement, decreases. This effect can be observed especially at the sharp edges. The faster the object moves, the higher its pressure gets. At the point where the pressure of the object equals the vapor pressure of water the liquid starts to vaporize and a gas bubble builds around the object. That’s the so called suvercaviation.

The characteristics of supercaviation

Supercaviation can be observed especially at the sharp edges of an object. The three main factors for supercaviation are the pressure surrounding the object, its inner pressure and the pressure of gravity. Naval architects try to eliminate this effect. The gas bubbles reduce the effectiveness of turbines, propeller and pumps. Furhtermore the shock waves of these bubbles benefit the oxidation of the metallic parts.

Supercaviation is an extreme form of caviation. By building these gas bubbles around the whole objects the objects can move almost as fast as in air. However the pressure within the bubble isn’t constant at all. That’s why the analyzation and mesuarements of the supercaviation is very difficult.

The gas bubble is alwayls longer than the surrounded object. Only the front part of the object are is in contact with the aqueous media. As listed above the pressure is the strongest at sharp edges which enables the possibility of the supercaviation. That’s why the shape of the top of the object is of high relevance.

The effect of supercaviation is used by the SuperPenetrator. Find all the information about the SuperPenetrator and many useful tips and tricks about big game hunting in Africa on grosswildjagd.de.

The military use of supercaviation

Of course supercaviation is also used for military actions. The Naval Undersea Warface Center in Newport, Rhode Island has developed a projectile which broke the sonic barrier for the first time underwater. In 1997 scientists injected air into the front part of the projectile in order to enable supercaviation. Supercaviation was first used during the gulf war for destroying harbour mines. The special projectiles were launched by helicopters and airplanes. Due to the fast underwater movement these weapons were able to destroy these mines from a safe distance.