In Tom Clancy's book The Hunt for Red October a Russian submarine is described which uses...

Transcribed Image Text:

In Tom Clancy's book The Hunt for Red October a Russian submarine is described which uses a silent "caterpillar" drive (a magnetohydrodynamic drive with no moving parts) instead of a propeller. Even though the propulsion system is very quiet, the submarine may still make a lot of noise if it goes too fast. The reason is that, if the speed of the submarine is too high, the static pressure at the point of maximum velocity over the submarine will drop below the saturated water vapor pressure and the water will boil, or cavitate. When the bubbles that form collapse, they make a lot of noise, making it easy to detect the submarine. The flow will not cavitate as long as the static pressure is greater than the saturated water vapor pressure, pv. For the purposes of this problem, assume the ocean has a uniform kg density p = 1000 atmospheric pressure acting on the surface of the ocean is p² = 101 kPa m3° (1.01 x 105, the acceleration due to gravity is g = 9.81, the saturated water vapor pressure at 12°C is p = 1.4 kPa, and that the entire ocean has a uniform temperature of 12°C. a) If the maximum velocity over the surface of the submarine is 2.0 times the freestream velocity, how fast can the submarine go at a depth of 100 m without cavitation? b) In order to go faster without being detected, should the submarine increase or decrease its depth? 1 Explain your answer. In Tom Clancy's book The Hunt for Red October a Russian submarine is described which uses a silent "caterpillar" drive (a magnetohydrodynamic drive with no moving parts) instead of a propeller. Even though the propulsion system is very quiet, the submarine may still make a lot of noise if it goes too fast. The reason is that, if the speed of the submarine is too high, the static pressure at the point of maximum velocity over the submarine will drop below the saturated water vapor pressure and the water will boil, or cavitate. When the bubbles that form collapse, they make a lot of noise, making it easy to detect the submarine. The flow will not cavitate as long as the static pressure is greater than the saturated water vapor pressure, pv. For the purposes of this problem, assume the ocean has a uniform kg density p = 1000 atmospheric pressure acting on the surface of the ocean is p² = 101 kPa m3° (1.01 x 105, the acceleration due to gravity is g = 9.81, the saturated water vapor pressure at 12°C is p = 1.4 kPa, and that the entire ocean has a uniform temperature of 12°C. a) If the maximum velocity over the surface of the submarine is 2.0 times the freestream velocity, how fast can the submarine go at a depth of 100 m without cavitation? b) In order to go faster without being detected, should the submarine increase or decrease its depth? 1 Explain your answer.

Answer rating: 100% (QA)

Ans a To determine the maximum speed at which the submarine can travel at a depth of 100 meters with... View the full answer