What Research About Motors Can Teach You
February 4, 2017
What is Underwater Propulsion?
In order to increase the range underwater of scuba and rebreather divers, they use an item of diving equipment called underwater propulsion vehicle, also known as underwater scooter or diver propulsion vehicle or DPV.
Range is described under three conditions, and these are the limited amount of breathing gas that can be carried, the rate at which the breathing gas is used under efforts while diving, and the limited time imposed by dive tables to prevent decompression sickness among divers.
A DPV has several structures, and these are a pressure-resistant watertight casing that contains a battery-operated electric motor, which drives a propeller. Some factors are considered in the design of this vehicle, and these are that it cannot harm the diver, diving equipment, marine life, and that it cannot run away from the diver or accidentally started, and the vehicle is to remain neutrally buoyant while being used underwater.
DPVs are typically used in cave diving and technical diving where the vehicles serve as a help in moving bulky equipment and thus allowing the diver to make better use of the limited underwater time as stated by the decompression requirements for deep diving. There are also DPV accessories that can be attached onto the DPV accessory board and these can make the DPV more useful. The accessories that can be mounted on to the DPV are compasses, cameras, lobster sticks and even spear guns.
Military applications also use a DPV to deliver combat divers and their equipment at speeds and distances that seem impossible.
The operation of DPV requires more than situational awareness than mere simple swimming since its operation requires simultaneous depth control, buoyancy adjustment, monitoring of breathing gas and navigation.
There are several types of DPV, and the most common type is that which tows the diver while holding onto the handles on the stern or bow. With the diver placed parallel to and above the propeller wash, this tow-behind scooter is at its most efficient operation.
The next kind of DPV is termed manned torpedoes, shaped like a fish, where the one or more divers can sit typically astride on it or in hollows inside.
The next kind of DPV is called a subskimmer which is described as a rigid-hulled inflatable boat, powered by a petrol engine when on the surface, and when being submerged, the petrol engine is sealed and the vehicle runs on battery-electric thrusters being attached on a steerable cross arm.
By now, you would have realized that as DPVs get larger, they gradually become submarines. Small submarines are called wet subs where the pilot’s seat is flooded and thus has to wear a diving gear.
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