2.2.4 Fluid Dynamics Flashcards
What is density?
How closely packed particles are in a solid, liquid or gas.
What is the formula for density?
mass x volume
To convert density from kg/m³ to g/cm³?
Divide by 1000
What is SG?
Specific gravity
What is specific gravity?
Relative density, used to compare densities of two substances.
How are the densities of liquids and solids compared?
Compared with water at 4 degrees.
How are the densities of gasses compared?
Compared with air at room temp.
What is the unit for SG?
There isn’t one as it is a ratio.
What can the SG of liquids be measured with?
A hydrometer.
What is viscosity?
Resistance of a fluid to change in shape.
What viscosity do cold heavy oils have?
High viscosity.
What happens to the viscosity of liquids as the temperature increases?
Decreases.
What happens to the viscosity of gases as the temperature increases?
Increases.
What is fluid resistance?
Resistance to motion in a fluid when a solid travels through a gas or liquid.
What determines the resistance on a fluid?
Viscosity
Surface texture
Shape of object
What is the speed of sound at sea level?
340m/s
What is ISA?
International standard atmosphere
If a liquid is compressible, what would happen when the pressure is increased?
Raise temp, lower viscosity, increase velocity.
What is pascals law?
When pressure is applied to a liquid in a container, it exerts pressure at right angles.
What is static pressure?
It exists in addition to any dynamic factors that are already there.
What is dynamic pressure?
The pressure that emerges from velocity of fluid in motion.
What is total pressure?
The sum of dynamic and static pressure.
Which type of pressure does pascals law apply too?
Static
What is Bernoulli’s theorem?
When energy is neither added or taken from a fluid in motion, the potential energy and pressure decrease when the kinetic and velocity increase.
What did Bernoulli realise?
The potential energy is created by the fluids pressure, whereas the kinetic energy is caused by the fluids movement.
