Just like aircraft use thrust to move along the sky, so too do ships and boats in the water. This thrust may be produced through multiple means, including those such as marine propeller systems, pump-jets, sails, and buoyancy. Throughout history, engineers have implemented many technologies to help improve upon the capabilities of thrust, each presenting different methods of marine propulsion. In this blog, we will discuss a few of the main types of marine propulsion systems and how they generate thrust for marine vessels.
One of the most common types of mechanical propulsion systems is the
marine propeller. Also known as screws, marine propellers are helically shaped devices that transform rotational motion into thrust as they operate, and such thrust is the result of a pressure difference formed between two surfaces. There are many types of propellers, and common examples include the twin, contra-rotating, controllable-pitch, and nozzle-style marine propeller. For the operation of a marine propeller, power is provided to the propeller shaft from the engine.
Pump-jets are another marine system that produces thrust, commonly used on small vessels, military vessels, and ferries. For the typical pump-jet, the process of producing thrust first begins by bringing water into the engines through induct valves. Depending on the desired speed of water throughout the pump, centrifugal or axial flow designs may be used. The pump then increases the pressure of the water within the inlet, and it is thrust out of the system through a nozzle to produce propulsion for the vessel. When braking, the vessel may utilize a reversing bucket, enabling it to slow down and have better maneuverability.
Sails are one of the oldest and most basic methods of producing thrust for
marine vessels, their first uses dating back to 5500 BCE. Sails are tensile structures that utilize power from the wind to move boats and ships. Commonly, sails are used for sailboats, ice boats, windsurfers, sailing ships, and sail-powered land vehicles. Through manipulating the sail's angle of attack, lift and drag can be controlled to adjust the velocity of the vessel. By aligning the sail's leading edge to the apparent wind, sails can produce propulsive force similar to that of how an aircraft wing creates lift. For the manufacturing of sails, common materials include polyester cloth, bonded filaments, canvas, and other fabrics and membrane materials.
Buoyancy is another property of vessels that some types can take advantage of to create thrust, such as underwater gliders. Underwater gliders are autonomous underwater vehicles (AUV) that utilize buoyancy for operation. In general, an underwater glide may use wings or their hull shape to convert buoyancy to thrust. Wings of the AUV, also known as hydrofoils, are used to create forward glide while the aircraft moves downwards. Once the vehicle reaches a certain depth, it then begins to climb forwards and upwards through reversing buoyancy. Through alternatively making buoyancy positive and negative, tooth-saw profiles are formed.
When it comes time to begin sourcing marine propeller and underwater glider components that you need for your operations, Aerospace Exchange has you covered with everything you are searching for from top marine propulsion parts manufacturers such as Kingsbury Inc., Twin Disc Inc., and more. Aerospace Exchange is owned and operated by ASAP Semiconductor, and we can help you find the aviation, NSN, and electronic parts that you are searching for, new or obsolete. As a premier supplier of parts for the aerospace, civil aviation, and defense industries, we're always available and ready to help you find all the parts and equipment you need, 24/7x365. ASAP Semiconductor is an FAA 0056B accredited and AS9120B, ISO 9001:2015 certified enterprise. For a quick and competitive quote, email us at sales@aerospaceexchange.com or call us at +1-714-705-4780.
