Momentum Equation

If you just have the continuity equation, it is still dead water. Momentum term of the Navier-Stokes equations describes how the fluid reacts to force:

It means the change of velocity is the combined result caused by following effects:

Advection – fluid can transport along its own velocity field.

Pressure – force from pressure gradient. For example, wind blows from high pressure area to where pressure is lower.

External Force applied per unit mass. For example, stirring a cup of tea will cause it to move. Gravity will cause ink to sink in water.

Viscous force due to friction. Sticking glue has more resistance to flow than clean water.

Momentum equation can taken as the fluid version of F = ma.

more information

Advertisements

Leave a comment

Filed under Fluid

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s