Thermo Flashcards
Work
dW = Fdl
Potential Energy
PE = (mgz)/ gc
Kinetic Energy
KE = (mv^2)/2gc
Work in fluid system
dW = -PdV
Ideal Gas Constants (R)
8.314 J/mol K or Pa m3/mol K
0.08205 L atm/mol K
1.987 cal/mol K
10.73 ft3 psi/lbmol R
0.73 ft3 atm/lbmol R
Work done on the system
Endergonic
Work done by the system
Exergonic
Heat absorbed by the system
Endothermic
Heat release by the system
Exothermic
Gibbs Phase Rule
F = 2 - pi + N
pi - # of phases (liq solid gas)
N - # of components (water, alcohol etc)
Joule’s Experiment
Win = Qout
delta PE = mCp(deltaT)
Heat Capacity Cp water
4.184 kJ/kg K
1 BTU/lbm F
Internal Energy
delta U = Q + W
Enthalpy
delta H = delta U + delta (PV)
dH = dU + d(PV)
Heat Capacity C
C = dQ/dT
Isochoric (V=k)
W = 0
Cp = dU/dT
Q = delta U = integral CvdT
Isobaric (P=k)
W = -PdV = -RdT (for ideal gas)
Q = delta H = integral CpdT
Introduced Zeroth Law of Thermodynamics
Ralph Howard Fowler
State that exists between two subsystems of equal temperature
Thermal Equilibrium
Introduced the First Law of Thermodynamics
Rudolf Julius Emmanuel Clausius
Energy conserved after the transfer of heat or work
Internal Energy
Energies in transit. Only exists when energy is being transferred from one system to the next
Heat and Work
Functions that depend on the current state of the system and not on how the system reaches that state
State / Point Function
H S T P V
Functions that depend on the path followed during the process
Path Function
W Q
Closed System Energy Balance (Non-flow)
delta U = Q + W
Open System Energy Balance (Steady Flow)
delta H + delta PE + delta KE = Q + Ws
Isothermal (T=k)
W = RT ln(V1/V2)
= RT ln(P2/P1)
Q = -W
delta U = 0
delta H = 0
Adiabatic
Q = 0
W = delta U
Pump Work
Wact = W/eff
Turbine Work
Wact = W x eff
Density of Water
1000 kg/m3
62.4 lb/ft3
