SUAVE.Components.Energy.Converters.Expansion_Nozzle.Expansion_Nozzle Class Reference

Inheritance diagram for SUAVE.Components.Energy.Converters.Expansion_Nozzle.Expansion_Nozzle:

Public Member Functions
def	__defaults__ (self)
def	compute (self, conditions)

Public Attributes
	tag
	polytropic_efficiency
	pressure_ratio
Public Attributes inherited from SUAVE.Components.Energy.Energy_Component.Energy_Component
	inputs
	outputs
Public Attributes inherited from SUAVE.Components.Physical_Component.Physical_Component
	tag
	mass_properties
	origin
	symmetric
Public Attributes inherited from SUAVE.Components.Component.Component
	tag
	origin
	generative_design_max_per_vehicle
	generative_design_characteristics
	generative_design_special_parent

Static Public Attributes
	gamma = conditions.freestream.isentropic_expansion_factor
	Cp = conditions.freestream.specific_heat_at_constant_pressure
	Po = conditions.freestream.pressure
	Pto = conditions.freestream.stagnation_pressure
	Tto = conditions.freestream.stagnation_temperature
	R = conditions.freestream.gas_specific_constant
	Mo = conditions.freestream.mach_number
	Tt_in = self.inputs.stagnation_temperature
	Pt_in = self.inputs.stagnation_pressure
	pid = self.pressure_ratio
	etapold = self.polytropic_efficiency
	Pt_out = Pt_in*pid
	Tt_out = Tt_in*pid**((gamma-1)/(gamma)*etapold)
	ht_out = Cp*Tt_out
	Mach = np.sqrt((((Pt_out/Po)**((gamma-1)/gamma))-1)*2/(gamma-1))
float	i_low = Mach < 1.0
float	i_high = 1.0
float	P_out = 1.0 *Mach/Mach
	T_out = Tt_out/(1+(gamma-1)/2*Mach*Mach)
	h_out = Cp*T_out
	u_out = np.sqrt(2*(ht_out-h_out))
float	rho_out = P_out/(R*T_out)
tuple	area_ratio = (fm_id(Mo,gamma)/fm_id(Mach,gamma)*(1/(Pt_out/Pto))*(np.sqrt(Tt_out/Tto)))
	stagnation_temperature
	stagnation_pressure
	stagnation_enthalpy
	mach_number
	static_temperature
	density
	static_enthalpy
	velocity
	static_pressure
	area_ratio

Detailed Description

This is a nozzle component intended for use in expansion.
Calling this class calls the compute function.

Assumptions:
Pressure ratio and efficiency do not change with varying conditions.
Subsonic or choked output.

Source:
https://web.stanford.edu/~cantwell/AA283_Course_Material/AA283_Course_Notes/

Member Function Documentation

__defaults__()

def SUAVE.Components.Energy.Converters.Expansion_Nozzle.Expansion_Nozzle.__defaults__

(

self

)

This sets the default values for the component to function.

Assumptions:
None

Source:
N/A

Inputs:
None

Outputs:
None

Properties Used:
None

Reimplemented from SUAVE.Components.Energy.Energy_Component.Energy_Component.

compute()

def SUAVE.Components.Energy.Converters.Expansion_Nozzle.Expansion_Nozzle.compute	(		self,
			conditions
	)

This computes the output values from the input values according to
equations from the source.

Assumptions:
Constant polytropic efficiency and pressure ratio
If pressures make the Mach number go negative, these values are corrected

Source:
https://web.stanford.edu/~cantwell/AA283_Course_Material/AA283_Course_Notes/

Inputs:
conditions.freestream.
  isentropic_expansion_factor         [-]
  specific_heat_at_constant_pressure  [J/(kg K)]
  pressure                            [Pa]
  stagnation_pressure                 [Pa]
  stagnation_temperature              [K]
  specific_gas_constant               [J/(kg K)] 
  mach_number                         [-]
self.inputs.
  stagnation_temperature              [K]
  stagnation_pressure                 [Pa]

Outputs:
self.outputs.
  stagnation_temperature              [K]  
  stagnation_pressure                 [Pa]
  stagnation_enthalpy                 [J/kg]
  mach_number                         [-]
  static_temperature                  [K]
  static_enthalpy                     [J/kg]
  velocity                            [m/s]
  static_pressure                     [Pa]
  area_ratio                          [-]
  denisty                             [kg/m^3]

Properties Used:
self.
  pressure_ratio                      [-]
  polytropic_efficiency               [-]

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

• /Users/emiliobotero/Dropbox/SUAVE/SUAVE/trunk/SUAVE/Components/Energy/Converters/Expansion_Nozzle.py