RCAIDE.Library.Attributes.Gases.Steam

Steam#

class Steam(*args, **kwarg)[source]#

Bases: Gas

A class representing water vapor (steam) and its thermodynamic properties. Provides methods for computing various gas properties including density, speed of sound, and specific heat.

tag#

Identifier for the gas type (‘steam’)

Type:

str

molecular_mass#

Molecular mass of H2O in kg/kmol (18.0)

Type:

float

gas_specific_constant#

Specific gas constant in m²/s²-K (461.889)

Type:

float

composition#

Chemical composition of steam

  • H2Ofloat

    Mass fraction of water vapor (1.0)

Type:

Data

Notes

This class implements steam properties assuming ideal gas behavior for most calculations. All properties are for pure water vapor.

compute_density(T=300, p=101325)[source]#

Computes steam density using the ideal gas law.

Parameters:

  • T (float) – Temperature in Kelvin

  • p (float) – Pressure in Pascal

Returns:

rho – Density in kg/m³

Return type:

float

Notes

Major Assumptions * Steam behaves as an ideal gas

compute_speed_of_sound(T=300, p=101325, variable_gamma=False)[source]#

Computes speed of sound in steam.

Parameters:

  • T (float) – Temperature in Kelvin

  • p (float) – Pressure in Pascal

  • variable_gamma (bool) – If True, uses temperature-dependent specific heat ratio

Returns:

a – Speed of sound in m/s

Return type:

float

Notes

Major Assumptions

  • If variable_gamma is False, assumes γ = 1.33

  • Steam behaves as an ideal gas

compute_cp(T=300, p=101325)[source]#

Computes specific heat capacity at constant pressure using a 3rd-order polynomial fit.

Parameters:

  • T (float) – Temperature in Kelvin

  • p (float) – Pressure in Pascal

Returns:

cp – Specific heat capacity in J/(kg·K)

Return type:

float

Notes

Major Assumptions

  • Valid for temperature range: 300 K < T < 1500 K

Theory .. math:

c_p(T) = c_1T^3 + c_2T^2 + c_3T + c_4

References

[1] Carvalho, M. G., Lockwood, F. C., Fiveland, W. A., & Papadopoulos, C. (2022). Combustion Technologies for a clean environment: Selected papers from the proceedings of the first international conference, Vilamoura, Portugal, September 3-6, 1991. CRC Press.

compute_gamma(T=300, p=101325)[source]#

Returns the specific heat ratio for steam.

Parameters:

  • T (float) – Temperature in Kelvin

  • p (float) – Pressure in Pascal

Returns:

g – Specific heat ratio (gamma) [unitless]

Return type:

float

Notes

Major Assumptions

  • Valid for temperature range: 233 K < T < 1273 K

  • Uses constant value of 1.33

compute_absolute_viscosity(T=300, p=101325)[source]#

Returns the absolute (dynamic) viscosity of steam.

Parameters:

  • T (float) – Temperature in Kelvin

  • p (float) – Pressure in Pascal

Returns:

mu – Absolute viscosity in kg/(m·s)

Return type:

float

Notes

Major Assumptions

  • Uses constant value of 1e-6 kg/(m·s)