Thermodynamics 1 Equations Flashcards
Sign Convention for Heat
Heat IN is +ive
Sign Convention for Work
Work OUT is +ive
Displacement Work
W = int P dV
Isothermal PV relationship
P V = m R T
Isentropic PV relationship
P V^γ = k
First Law of Thermodynamics
Q - W = ΔU (for a closed system)
Enthalpy Definition
h = u + P v
Ideal Gas Law
P v = R T
Specific Heat (constant volume)
Cv = du/dT
Change in u
u2 - u1 = Cv * ( T2 - T1 )
Specific Heat (constant pressure)
Cp = dh/dT
Change in h
h2 - h1 = Cp * ( T2 - T1 )
Specific Heat Relationship
R = Cp - Cv
γ in terms of specific heats
γ = Cp / Cv
Dryness fraction from specific volume
x = (v - vf) / (vg - vf)
Dryness fraction from specific enthalpy
x = (h - hf) / (hg - hf)
Dryness fraction from specific entropy
x = (s - sf) / (sg - sf)