Register to reply

Force of Moving Water

by Ideologue
Tags: force, moving, water
Share this thread:
Jun26-06, 01:39 AM
P: 21
Does anyone know of an equation I may use to calculate the force of moving water? I am trying to theoretically workout the resistive force a vehicle would meet if it were to drive upstream (hydrodynamic drag).

I am assuming the main parameters such an equation would include are water depth, water speed, water density and the surface area of the exposed parts of the vehicle such as the portion of its tyres submerged in the stream.

Phys.Org News Partner Physics news on
'Squid skin' metamaterials project yields vivid color display
Team finds elusive quantum transformations near absolute zero
Scientists control surface tension to manipulate liquid metals (w/ Video)
Jun26-06, 02:01 AM
P: 209
Force=v*rate of change of mass
F=Apv^2, where p = density of water, v=velocity of water, A=surface area
Jun26-06, 02:19 AM
P: 21
Thank you very much, Harmony.

Jun26-06, 02:55 AM
P: 21
Force of Moving Water

I am wondering now if it is possible to use exactly the same equation for calculating aerodynamic drag as is used for calculating hydrodynamic drag?

Instead of using a figure for air density, a figure for water density is employed. The coefficient of drag remains the same.

What do you think?

Aerodynamic drag is: F = 0.5PV²Cdf


P = air density
V = velocity
Cd = coefficient of drag
f = frontal area

Edit: Of course the coefficient of drag would be specific to the part of the vehicle subjected to the flowing water.

Register to reply

Related Discussions
Waves moving in shallow water General Physics 5
Moving Water General Physics 2
Electromagnetic energy of moving water! General Physics 2
Moving water... General Engineering 8
Moving water... General Physics 1