Notations

We use the following notations:

Notation	Value	Type	Unit
emm	effective molecular mass of vapor	parameter	g/mol
P	fluid current pressure	variable	PaA
Patm	atmospheric pressure: 1.013.105 PaA	constant	PaA
	high saturated vapor pressure	parameter	PaA
	low saturated vapor pressure	parameter	PaA
Ru	universal gas constant: 8.314	constant	J/mol/K
T	fluid current temperature	parameter	K
T0	reference fluid temperature: 273.15 K (0 degC)	constant	K
V	volume	variable	m3
x	volumetric air/gas content	parameter	%
θ	volumetric fraction of vapor	variable	null
	absolute viscosity of air/gas	parameter	cP
	fluid absolute viscosity at current P and T	variable	cP
	absolute viscosity of vapor	parameter	cP
	density of air at Patm and 273 K	constant	kg/m3
	fluid density at current pressure P and T	variable	kg/m3
	reference density of the liquid part at Patm and 273K	constant	kg/m3
y	isentropic polytropic index	parameter	null
Γ		parameter	null
ф	Volumetric fraction of free air/gas	variable	null

All the pressures (or Bulk modulus) and temperatures in the following formulae are taken to be absolute (PaA and K).

Warning

Remark about the notations, to avoid misunderstanding for people who would compare this Technical Bulletin N°118 for HYD Bosch Fuel Properties and the Technical Bulletin N°117 for HYD Advanced Fluid Properties:

Be careful: The volumetric fraction of free air/gas is noted ф in this technical bulletin (TB118) and in the C code of HYD Bosch fuel properties, whereas it is noted θ in the technical bulletin (TB117) and in the C code of HYD advanced fluid properties.

Additionally the volumetric fraction of vapor is noted θ in this technical bulletin (TB118) and in the C code of HYD Bosch fuel properties, whereas we consider a mass fraction of vapor which is noted ф in the Technical Bulletin N°117 and in the C code of HYD Advanced Fluid Properties.