A viscous force and inertial force b inertial force and gravity c pressure force and inertial force d pressure force and viscous force
Answers
Answer:
regularly heard of the terms like viscous force and the inertial force.
Now the viscous forces are the forces due to to the friction between the the layers of any real fluid. In fluid mechanics we take the fluid as in the continuum condition, which means fluid particles are very closely packed so necessarily there is friction between layers of fluid.
Inertial force, as the name implies is the force due to the momentum of the fluid. This is usually expressed in the momentum equation by the term ρ(du/dt) or (ρv)v. So, the denser a fluid and is, and the higher its velocity, the more momentum (inertia) it has. As in classical mechanics, a force that can counteract or counterbalance this inertial force is the force of friction (shear stress) or viscous force. In the case of fluid flow, this is represented by Newtons law, τx=μdvdy. This is only dependent on the viscosity and gradient of velocity. Then, Re=ρvLμ, is a measure of which force dominates for a particular flow.
Inertial force (in the direction of flow) and viscous force (in the reverse direction of flow) act in opposite direction.
What is convective inertial force and unsteady inertial force, what they physically mean
Inertial force (per fluid unit volume) is simply the name of the term to the left of the equal sign in the above equation. The justification usually given for this nomenclature is related to the fact that the term is proportional to fluid inertial mass, via fluid density. Then, the left hand side can be written as [ local (or unsteady) inertial force + convective inertial force ] / fluid unit volume.