Fluid Dynamics Flashcards
What’s the formula for density?
Mass / volume
Does density vary with pressure and temperature?
Yes.
How do you work out the specific gravity?
Density of substance / density of water
What’s a hydrometer used for?
Read directly the density of a liquid.
And calibrated to read specific gravity/ relative density
What are the units of viscosity?
Ns/m squared
How does kinematic viscosity change for a liquid and a gas?
Liquid- decrease with higher temperature
Gas- increase with higher temperature
What can the resistance to fluid flows be divided into?
Skin Friction
Turbulence
What’s the formula for fluid flow ?
Velocity x cross sectional area (metres cubed/ second)
What is the pressure of energy formula?
Pressure of fluid x volume of fluid displaced
What’s the pressure equation better known as?
Bernoulli’s thereom, can only be valid for incompressible flow.
What’s the relation between velocity and pressure in Bernoulli’s
?
Higher velocity = decrease in pressure
For divergent ducts, what happens to incompressible flow?
Dynamic pressure decreases, pressure increases
