67hat34c
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My Cousin answered a question for me and here is his answer. found this interesting and could possibly help answer some questions regarding our hulls etc.
The fluid dynamics are the same since both airplanes and boats are moving through a fluid (although with vastly different densities and reynoulds numbers at a given velocity). You’ve probably heard about the fluid dynamic effect on ships called “squat”. As a ship moves faster in the water, the bottom of the ship acts like an upside down airplane wing and pulls the ship down into the water. This effect was unfortunately discovered the hard way when a vessel moved at high speed through an area it normally would pass and struck bottom.
SHIP SQUAT AND ITS CALCULATION by Dr Charles B. Barrass
When a ship proceeds through water, she pushes water ahead of her. In order not to leave a "hole" in the water, this volume of water must return down the sides and under the bottom of the ship. The streamlines of return flow are speeded up under the ship. This causes a drop in pressure, resulting in the ship dropping vertically in the water. As well as dropping vertically, the ship generally trims forward or aft. The overall decrease in the static under keel clearance, forward or aft, is called Ship Squat.
This paper explains the phenomenon known as "Ship Squat". The dangers caused by ship squat and the factors governing the extend of ship squat is further explored. A practical calculation of the squat is explained and formulae are provided so as to predict the maximum ship squat for a given situation. The formulae quoted in this report would provide ship owners some firm guidelines in the extend of ship squat.
The fluid dynamics are the same since both airplanes and boats are moving through a fluid (although with vastly different densities and reynoulds numbers at a given velocity). You’ve probably heard about the fluid dynamic effect on ships called “squat”. As a ship moves faster in the water, the bottom of the ship acts like an upside down airplane wing and pulls the ship down into the water. This effect was unfortunately discovered the hard way when a vessel moved at high speed through an area it normally would pass and struck bottom.
SHIP SQUAT AND ITS CALCULATION by Dr Charles B. Barrass
When a ship proceeds through water, she pushes water ahead of her. In order not to leave a "hole" in the water, this volume of water must return down the sides and under the bottom of the ship. The streamlines of return flow are speeded up under the ship. This causes a drop in pressure, resulting in the ship dropping vertically in the water. As well as dropping vertically, the ship generally trims forward or aft. The overall decrease in the static under keel clearance, forward or aft, is called Ship Squat.
This paper explains the phenomenon known as "Ship Squat". The dangers caused by ship squat and the factors governing the extend of ship squat is further explored. A practical calculation of the squat is explained and formulae are provided so as to predict the maximum ship squat for a given situation. The formulae quoted in this report would provide ship owners some firm guidelines in the extend of ship squat.
