Nabla1
Electrical
- Dec 26, 2007
- 32
After looking at some fluid dynamics basics, the maths seems to be centered around three main (partial differential) equations:
The continuity equation (rate of mass flow)
The Navier-Stokes equations (rate of change of momentum)
The energy equations (rate of energy transfer)
These equations treat the various properties of fluid (velocity, density, momentum etc..) as physical scalar (e.g. density) or vector (e.g. momentum) fields. The fluid is treated as a continuum, and is hence differentiable, which is why the above equations work.
My question: If fluids are CONTINUOUSLY variable in all of their properties, then why do many sources talk about fluid being LAYERED? This suggests that the fluid is not continuous and differentiable, but is actual DISCRETE.
(Many sources I have read talk about things like "layered flow", "boundary layers", and "random particle movement between layers")
Thanks, help is much appreciated.
The continuity equation (rate of mass flow)
The Navier-Stokes equations (rate of change of momentum)
The energy equations (rate of energy transfer)
These equations treat the various properties of fluid (velocity, density, momentum etc..) as physical scalar (e.g. density) or vector (e.g. momentum) fields. The fluid is treated as a continuum, and is hence differentiable, which is why the above equations work.
My question: If fluids are CONTINUOUSLY variable in all of their properties, then why do many sources talk about fluid being LAYERED? This suggests that the fluid is not continuous and differentiable, but is actual DISCRETE.
(Many sources I have read talk about things like "layered flow", "boundary layers", and "random particle movement between layers")
Thanks, help is much appreciated.