Thermodynamics Flashcards
Branch of engineering that deals with the energies possessed by gases and vapors
Thermodynamics
Definite area of a space where some thermodynamic process takes place
Thermodynamic system
System of fixed mass whose boundaries are determined by the space of the working substance occupied in it
Closed system
System where the working substance crosses the boundary
Open system
System of fixed mass where no heat or work cross the boundary
Isolated system
When no further changes are observed, a thermodynamic system is said to be in…
Thermal equilibrium
When two bodies are in thermal equilibrium with a third body, they are in…
Thermal equilibrium
(BLANK) can neither be created nor destroyed, though it can be transformed from one form to another
Energy
Mathematically, the first law of thermodynamics (energy can neither be created nor destroyed) is defined as:
Heat = work + internal energy
There is a definite limit to the amount of (BLANK), which can be obtained from a given quantity of heat energy
Mechanical work
State of substance whose evaporation from its liquid state is complete
Perfect gas
The absolute pressure of a given mass of a perfect gas varies (BLANK) as its volume, when the temperature remains constant
Inversely
The volume of a given mass of perfect gas varies (BLANK) as its absolute temperature, when the absolute pressure remains constant
Directly
The absolute pressure of a given mass of a perfect gas varies (BLANK) as its absolute temperature
Directly
The change in internal energy of a perfect gas is (BLANK) proportional to the change in temperature
Directly
Mathematically, the change in energy is related to change in temperature as…
dE = mcdT (c = specific heat)
(Isochoric process) when gas is heated at a constant pressure, its temperature and volume (BLANK)
Increase
Process in which the temperature of the working substance remains constant during its expansion or compression
Isothermal process
Process in which the working substance neither receives nor gives out heat to its surroundings
Adiabatic or isentropic process
Process that occurs when a fluid is allowed to expand suddenly into a vacuum chamber through an orifice of large dimensions. Heat remains constant.
Free expansion
Process in which a perfect gas is expanded through an aperture of minute dimensions
Throttling
Total heat content of a system, mathematically equal to the internal energy plus the product of pressure and volume
Enthalpy
Always increases or stays the same in a thermodynamic system
Entropy
Consists of a series of thermodynamic operations which take place in a certain order, and the initial conditions are restored at the end of the process
Thermodynamic cycle
A process in which some change in the reverse direction reverses the process completelyq
Reversible cycle
A process in which the change in the reverse direction does not reverse the process
Irreversible process
What the the common causes for an irreversible process?
Friction, radiation, conduction
The ratio of work done to the heat supplied during a cycle
Efficiency
A substance, which upon burning with oxygen in the atmospheric air, produces a large amount of heat
Fuel
The amount of heat generated by fuel
Calorific value
Type of fuel whose primary constituents are carbon and hydrogen
Hydrocarbon fuel
Almost all commercial liquid fuels are derived from (BLANK)
Natural petroleum (crude oil)
