Lectures 1-3 Flashcards
Absolute Pressure is…
The actual pressure at a given position. Relative to Absolute Vacuum (absolute zero pressure)
Gage pressure is…
Equation is…
Difference between absolute pressure and local pressure
P (gage) = P (abs) - P (atm)
Vacuum pressure is…
Equation is…
Pressure difference that the absolute pressure is below the Atmospheric pressure
P (vac) = P (atm) - P (abs)
Pascal’s Law states that…
Pressure of a fluid in a confined space is the same throughout the fluid.
Atmospheric pressure is often referred to as…
Barometric pressure
Isothermic process is…
Constant TEMPERATURE
Isobaric process is…
Constant PRESSURE
Isochoric process is…
Constant VOLUME
Adiabatic system is…
What can cross the system boundary?
Insulated system where no heat is transferred to surroundings.
Work.
Macroscopic forms of energy are…
Examples
Energy that the system processes as a whole.
Kinetic and potential
Microscopic forms of energy are…
Energy that is at the molecular level
Sensible energy is…
Internal energy that is associated with the kinetic energy of the molecules in the system
Portion of internal energy
Internal energy is…
Denoted with the letter…
The sum of all microscopic forms of energy (molecular energy)
U
Latent energy is…
Internal energy that is associated with the phase of a system
Chemical energy is…
Internal energy associated with the atomic bonds in a molecule of a sytem
Nuclear energy is…
Internal energy associated with the strong bonds within the nucleus of an atom itself (huge amounts of energy)
State work…
The energy transfer due to a force acting through a distance
Examples of work interactions in thermodynamics…
Rising piston, rotating shaft, even an electric wire crossing the system boundaries
State a pure substance…
A substance with a fixed chemical composition throughout
Compressed liquid is…
Aka…
A substance that is not about to vaporize
Aka Subcooled liquid
Saturated liquid is…
A liquid that is about to vaporize, BUT still FULLY liquid
Saturated (liquid-vapor) mixture is…
The state at which the liquid and vapor coexist in equilibrium of […]
Saturated vapor is…
A vapor that is about to condense but remains fully gaseous
Superheated vapor is…
A vapor that is not about to condense as it has additional energy to maintain its state
What does the area under a vapour dome represent for the state of the substance?
It is in the process of boiling. As they coexist under the line of vapour/liquid saturation
On a steam table, if your value for any (specific volume, internal energy, enthalpy) fall between the given values for Sat Liquid and Sat Vapour, what state is the substance in?
Saturated mixture
On a steam table, if your value for any (specific volume, internal energy, enthalpy) falls below the given value for Sat Liquid, what state is the substance in?
Compressed liquid
On a steam table, if your value for any (specific volume, internal energy, enthalpy) falls above Sat Vapour, what state is the substance in?
Superheated vapour
On a steam table, if your value for any (specific volume, internal energy, enthalpy) is equal to the Sat Liquid, what state is the substance in?
Saturated Liquid
On a steam table, if your value for any (specific volume, internal energy, enthalpy) is equal to the Sat Vapour, what state is the substance in?
Saturated vapour
Why are there no compressed liquid steam tables?
We assume that the liquid is in a state of IMCOMPRESSIBILITY
Steam Quality is…
Denoted by the letter…
Ratio of mass in the vapour phase, relative to the total mass
x
Formula for steam quality
Quality = mass of vapour / total mass
Critical point is…
The temperature and pressure at which no phase change is observed
Supercritical is…
any point above the critical temperature where there is a very high pressure due to liquid and vapour mixing
