SUAVE.Attributes.Gases.Air.Air Class Reference

Inheritance diagram for SUAVE.Attributes.Gases.Air.Air:

Public Member Functions
def	__defaults__ (self)
def	compute_density (self, T=300., p=101325.)
def	compute_speed_of_sound (self, T=300., p=101325., variable_gamma=False)
def	compute_cp (self, T=300., p=101325.)
def	compute_gamma (self, T=300., p=101325.)
def	compute_absolute_viscosity (self, T=300., p=101325.)
def	compute_thermal_conductivity (self, T=300., p=101325.)
def	compute_prandtl_number (self, T=300.)

Public Attributes
	tag
	molecular_mass
	gas_specific_constant
	specific_heat_capacity
Public Attributes inherited from SUAVE.Attributes.Gases.Gas.Gas
	tag
	molecular_mass
	gas_specific_constant
	composition

Detailed Description

Holds constants and functions that compute gas properties for air.

Assumptions:
None

Source:
None

Member Function Documentation

__defaults__()

def SUAVE.Attributes.Gases.Air.Air.__defaults__

(

self

)

This sets the default values.

Assumptions:
None

Source:
Values commonly available

Inputs:
None

Outputs:
None

Properties Used:
None

Reimplemented from SUAVE.Attributes.Gases.Gas.Gas.

compute_absolute_viscosity()

def SUAVE.Attributes.Gases.Air.Air.compute_absolute_viscosity	(		self,
			T = 300.,
			p = 101325.
	)

Compute the absolute (dynamic) viscosity
    
Assumptions:
Ideal gas

Source:
https://www.cfd-online.com/Wiki/Sutherland's_law

Inputs:
T                  [K]       - Temperature

Outputs:
absolute viscosity [kg/(m-s)]

Properties Used:
None

compute_cp()

def SUAVE.Attributes.Gases.Air.Air.compute_cp	(		self,
			T = 300.,
			p = 101325.
	)

Computes Cp by 3rd-order polynomial data fit:
cp(T) = c1*T^3 + c2*T^2 + c3*T + c4

Coefficients (with 95% confidence bounds):
c1 = -7.357e-007  (-9.947e-007, -4.766e-007)
c2 =    0.001307  (0.0009967, 0.001617)
c3 =     -0.5558  (-0.6688, -0.4429)
c4 =        1074  (1061, 1086) 
    
Assumptions:
123 K < T < 673 K 

Source:
Unknown, possibly Combustion Technologies for a Clean Environment 
(Energy, Combustion and the Environment), Jun 15, 1995, Carvalhoc

Inputs:
T              [K]       - Temperature
p              [Pa]      - Pressure

Outputs:
cp             [J/kg-K]

Properties Used:
None

compute_density()

def SUAVE.Attributes.Gases.Air.Air.compute_density	(		self,
			T = 300.,
			p = 101325.
	)

Computes air density given temperature and pressure

Assumptions:
Ideal gas

Source:
Common equation

Inputs:
T         [K]  - Temperature
p         [Pa] - Pressure

Outputs:
density   [kg/m^3]

Properties Used:
self.gas_specific_constant

compute_gamma()

def SUAVE.Attributes.Gases.Air.Air.compute_gamma	(		self,
			T = 300.,
			p = 101325.
	)

Computes Cp by 3rd-order polynomial data fit:
gamma(T) = c1*T^3 + c2*T^2 + c3*T + c4

Coefficients (with 95% confidence bounds):
c1 =  1.629e-010  (1.486e-010, 1.773e-010)
c2 = -3.588e-007  (-3.901e-007, -3.274e-007)
c3 =   0.0001418  (0.0001221, 0.0001614)
c4 =       1.386  (1.382, 1.389)
    
Assumptions:
233 K < T < 1273 K 

Source:
Unknown

Inputs:
T              [K]       - Temperature
p              [Pa]      - Pressure

Outputs:
g              [-]

Properties Used:
None

compute_prandtl_number()

def SUAVE.Attributes.Gases.Air.Air.compute_prandtl_number	(		self,
			T = 300.
	)

Compute the prandtl number 
    
Assumptions: 

Source:
N/A

Inputs:
specific_heat_capacity [J/kgK]
absolute viscosity     [kg/(m-s)]
thermal conductivity   [W/(m-K)]

Outputs:
prandtl number         [unitless]

Properties Used:
None

compute_speed_of_sound()

def SUAVE.Attributes.Gases.Air.Air.compute_speed_of_sound	(		self,
			T = 300.,
			p = 101325.,
			variable_gamma = False
	)

Computes speed of sound given temperature and pressure

Assumptions:
Ideal gas with gamma = 1.4 if variable gamma is False

Source:
Common equation

Inputs:
T              [K]       - Temperature
p              [Pa]      - Pressure
variable_gamma <boolean> - Determines if gamma is computed

Outputs:
speed of sound [m/s]

Properties Used:
self.compute_gamma() (if variable gamma is True)
self.gas_specific_constant

compute_thermal_conductivity()

def SUAVE.Attributes.Gases.Air.Air.compute_thermal_conductivity	(		self,
			T = 300.,
			p = 101325.
	)

Compute the thermal conductivity
    
Assumptions:
Properties computed at 1 bar (14.5 psia)

Source:
https://www.engineeringtoolbox.com/air-properties-viscosity-conductivity-heat-capacity-d_1509.html 

Inputs:
T                  [K]       - Temperature

Outputs:
thermal conductivity [W/(m-K)]

Properties Used:
None

---

The documentation for this class was generated from the following file:

• /Users/emiliobotero/Dropbox/SUAVE/SUAVE/trunk/SUAVE/Attributes/Gases/Air.py