Question

A 1:50 scale model of a ship is towed at 4.8 km/hr using a force of 9 N. If we assume the same fluid in the model as in the prototype, calculate the corresponding speed and force in the prototype if the flow is dominated by:________. (a) density and gravity (b) density and surface tension (c) density and viscosity (d) Which of the assumptions in (a)-(c) do you think is most appropriate

Answer 1

Answer:

A: density and gravity

Explanation:

The Froude Number is defined as a dimensionless parameter that measures the ratio of the force of inertia on an element of fluid to the weight of the fluid element. In simple terms, it's the force of inertia divided by the gravitational force.

Froudes number is usually expressed as;

Fr = v/√(gd)

Where;

Fr = froude number

v = velocity

g = gravitational acceleration = specific weight/density

d = depth of flow

Now, to calculate the corresponding speed and force in the prototype, it means we have to use equal froude number and thus this will mean that it has to be dominated by gravity and density.