Aero formulas

From NPrize
Revision as of 02:44, 10 April 2012 by Vincent (talk | contribs) (more entropy and gibbs energy)
Jump to navigationJump to search

Resources on physics related to aerodynamics

The List of elementary physics formulae on wikipedia is useful.

List of variables

Variable Meaning Unit (SI)
γ (gamma) Surface tension N.m-1 (Newton per meter)
μ (mu) or η (eta) Viscosity Pa·s (Pascal second) or P (Poise, 1 Poise is 0.1 Pa.s)
H Enthalpy: total energy of a thermodynamic system. J (Joule)
heat_vap.png or L Vaporization heat or Latent heat of vaporization: energy required to vaporize a mole of liquid at a given temperature. J.mol-1 (Joule per mole)
Q Amount of Heat J (Joule)
T Temperature K (Kelvin)
S Entropy J.K-1 (Joule per Kelvin)
U Internal energy of a system (see first law of Thermodynamics below) J (Joule)
V Volume m3 (cubic meter)
W Work: mechanical constraints on the system. J (Joule)
n Quantity of matter mol (mole)
p Pressure Pa (Pascal)

List of constants

Constant Meaning Value Unit (SI)
NA or N Avogadro constant, number of atoms or molecules in a mole. 6.02214129.1023 mol-1
R ideal gas constant 8.3144621 J.K−1.mol−1
kB or k Boltzmann constant, gas constant R divided by Avogadro number. 1.3806488.10-23 J.K-1

List of equations

Equation Name Meaning
pvnrtk.png Ideal gas equation Relation between properties of an ideal gas (state equation). k is kB.
clausius-clapeyron.png Clausius-Clapeyron relation Relation between the pressure, latent heat of vaporization and temperature of a vapour at two temperatures (approximation, at low temperatures).
Qdefinition.png Definition of Heat for an ideal gas. The heat required to change the temperature of a system from an initial temperature T0, to a final temperature, Tf.
QeqmL.png Heat at state change for an ideal gas. The heat required to change the state of a some matter, L being the latent heat. Delta H equals Q only when pressure is constant (isobaric).
dUeqdQmindW.png First law of Thermodynamics Variations of internal energy of a system between two states is the sum of the received heat and work (minus the given work).
enthalpy.png Enthalpy Total amount of energy of a system, defined as the sum of the internal energy U and pressure * volume.
workExpand.png Work of gas expansion. Work done by expanding an ideal gas.
entropy_dueqtdsmpdv.png Entropy Internal energy related to entropy variation for a closed system in thermal equilibrium (fundamental thermodynamic relation).
ΔSuniverse = ΔSsurroundings + ΔSsystem Entropy variation as a whole. Entropy variation of a system is generally compensated by the inverse variation of the surroundings not including losses.
gibbs.png Gibbs free energy / Free enthalpy Useful work obtainable from a system at isobaric and isothermal conditions.