What is the Froude number?

The Froude number is a dimensionless number used to quantify the influence of gravity on the motion of a fluid. It is the ratio of the inertia forces to the gravitational forces related to the mass of water displaced by a floating boat.

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Frictional resistance of the hull (calculation)

The frictional resistance is a force that is generated when the underwater parts of the boat and the water around are in relative movement (the boat moves through the water, or, in other words, the water passes down the boat). Therefore, it is a hydrodynamic force, and as a resistance, it works in the opposite direction to the movement, trying to slow the boat down.

Frictional resistance of a boat or yacht (calculation)

Calculate the total frictional resistance of a yacht: hull, keel, and rudder. The frictional resistance is a force that is generated when the underwater parts of the boat and the water around are in relative movement. It is a hydrodynamic force, and as a resistance, it works in the opposite direction to the movement, trying to slow the boat down.

The Reynolds number

The Reynolds number is the ratio of inertia forces to viscous forces involved in the flow. Reynolds understood that while inertia forces were dominant in a turbulent flow, viscous forces were prevalent in a laminar one. In this way, the Reynolds number can be used to determine whether a flow is laminar or turbulent.

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What the hydrodynamic resistance is and why it matters

The motion of a sailing yacht through water requires energy to overcome resistance. It is essential to know the mechanisms behind the generation of this force that works against the movement so that we can make the resistance of a new design match the project's overall performance goals.

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Total hydrodynamic resistance (calculation)

Total hydrodynamic resistance (calculation)

Hull parameters check (calculation)

Hull parameters check (calculation)