What is the formula for pressure in a fluid column?
height*density*gravity Mass = kg density = rho gravity = 9.81m/s^2
Note that pressure is the same in all directions and is independent of the size of the object on which pressure is being exerted.
Explain Bernoulli's' equation
Bernoulli's' equation is about the conversation of energy in fluid flow. It states that as fluid flows into a narrowing pipe the velocity will increase which means that the pressure will decrease. When a fluid flows in an expanding pipe the opposite happens.
What does mu μ symbolise in fluid dynamics
What does V symbolise in fluid dynamics
Viscocity is a measure of a fluids resistance to deformation. The symbol is μ and it is measured in (kg/ms). This is a result of the friction between the different layers.
Explain Stokes law
Stokes law calculates the drag on an object as it travels through a fluid.
FD = 6πRμV
FD = Drag force on the sphere
R= radius of the sphere
μ = viscocity of the fluid
V = relative velocity of the sphere
What is the relationship between viscocity and the reynolds nubmer
Reynolds number = inertia force/ (viscouse force)
Explain terminal velocity in a sphere.
Terminal velocity is the balance between the acceleration of gravity and the countering forces. The primary oppositional force is drag followed by buoyancy.
For a sphere this is
(Sphere Density-Fluid density)*(Sphere Volume)*(Gravity)
Explain Pouseuille's equation for pressure drop in a
Note this applies for laminar flow of viscous fluid in a straight pipe only
Pressure drop = 32*viscocity*length*average velocity
ΔP = (32*μL)*V(Bar)/D2
Explain the fanning friction factor
This is a dimensionless number that relates to the fluid flow in a pipe.
In a round pipe it is taken to be 16/Reynolds number.
This can also be calculated as 16μ/ρVD
What is the hydrolic dyameter
It is a metric for creating an equivalent round diameter pipes for non round pipes. It is calculated from 4A/P
P is wetted perimeter.
Explain the velocity pressure equation.
4*Friction*Length*density*average velocity squared
2 * diameter
Explain the velocity profile in laminar fluid flow
Velocity is slower and the boundary of fluid flow than the centre of fluid flow. The difference is called the boundary profile.