MARITIME – PROPULION & PERFORMANCE CALCULATOR
Propeller Induced Velocity
A precise tool.
What is the Propeller Induced Velocity & How does it work?
Actuator disc theory treats a propeller as an infinitely thin, uniformly loaded disk that imparts a pressure jump to the surrounding fluid. By applying conservation of mass and momentum across the disk, the theory links thrust, fluid density, and the velocity increase induced by the propeller. The induced velocity, often denoted vi, represents the additional axial speed imparted to the water as it passes through the propeller disk. This velocity is directly related to the thrust generated and inversely related to the product of fluid density and propeller area. In ship design, knowing vi helps engineers estimate propeller slip, required shaft power, and overall propulsion efficiency. The simple relationship derived from actuator‑disc theory provides a quick first‑order estimate before detailed CFD or experimental testing.
vi = sqrt{ frac{T}{2 rho A} }
vi = induced velocity (m/s)
Parameters
Result
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Frequently Asked Questions
What is propeller induced velocity?
Propeller induced velocity is the additional axial speed imparted to water by a propeller, directly related to thrust and fluid dynamics.
How does actuator disc theory apply to propellers?
Actuator disc theory treats a propeller as an infinitely thin disk that imparts pressure jumps to surrounding fluid, linking thrust, density, and induced velocity.
What factors affect the induced velocity of a propeller?
Induced velocity is affected by thrust, fluid density, and the size and efficiency of the propeller.
Why is induced velocity important in maritime navigation?
Induced velocity affects the performance and efficiency of ships, influencing speed and fuel consumption.
Can you explain the relationship between thrust and induced velocity?
Thrust generates induced velocity by accelerating water through the propeller, creating a pressure difference that pushes the ship forward.
How do I calculate induced velocity using this calculator?
Input the thrust, fluid density, and other relevant parameters into the calculator to determine the induced velocity of the propeller.
What are the units for induced velocity in this calculation?
Induced velocity is typically measured in meters per second (m/s) or knots.
Results are for informational purposes only and do not constitute professional advice.