A periscope is installed on a on a submarine. It has a...

A periscope is installed on a on a submarine. It has a submerged length of $3 \mathrm{~m}$ and a diameter of $60 \mathrm{~mm}$. If the submarine is traveling at $10 \mathrm{~m} / \mathrm{s}$, determine the moment developed at the base of the periscope. The water is at a temperature of $20^{\circ} \mathrm{C}$. Consider the periscope to be a smooth cylinder.

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Hydrodynamic Drag

Hydrodynamic drag is the resistive force exerted by a fluid on an object moving through it. This force is influenced by the velocity of the object, the density and viscosity of the fluid, and the geometry of the object. For simple shapes like cylinders, experimental drag coefficients are used along with dynamic pressure to quantify this force.

Dynamic Pressure and Fluid Properties

Dynamic pressure represents the kinetic energy per unit volume of a moving fluid and is calculated using the expression ½ ?v², where ? is the fluid density and v is the velocity. It is an essential factor in determining the magnitude of the drag force experienced by an object submerged in a fluid, and fluid properties like density and viscosity (dependent on temperature) play a critical role in these calculations.

Moment (Torque) Calculation

A moment, or torque, is the product of a force and the distance from the point about which the moment is calculated, often referred to as the lever arm. In the context of hydrodynamic loads on submerged structures, the drag force acting on the object is applied at a certain distance from its pivot or base, generating a moment which must be considered in structural analysis and design.

Transcript

Please give Ace some feedback