IAPWS97_RHO

This function computes the mass density of water or steam from temperature and pressure using the IF-97 industrial formulation. It is suited for fast property evaluation in engineering calculations.

The mapping is:

\rho = f(T, P)

where \rho is mass density, T is temperature, and P is pressure.

Excel Usage

=IAPWS97_RHO(T, P, use_ninety_five_boundary)

T (float, required): Water temperature (K).
P (float, required): Water pressure (Pa).
use_ninety_five_boundary (bool, optional, default: false): Use IAPWS-95 vapor-pressure boundary instead of IF-97 boundary (-).

Returns (float): Water density at the specified state (kg/m^3).

Example 1: Compressed water density

Inputs:

T	P	use_ninety_five_boundary
330	800000	false

Excel formula:

=IAPWS97_RHO(330, 800000, FALSE)

Expected output:

985.105

Example 2: Near critical state density

Inputs:

T	P	use_ninety_five_boundary
648.6	22500000	false

Excel formula:

=IAPWS97_RHO(648.6, 22500000, FALSE)

Expected output:

353.061

Example 3: Superheated steam density

Inputs:

T	P	use_ninety_five_boundary
823	14000000	false

Excel formula:

=IAPWS97_RHO(823, 14000000, FALSE)

Expected output:

40.3929

Example 4: High temperature region-five density

Inputs:

T	P	use_ninety_five_boundary
2000	30000000	true

Excel formula:

=IAPWS97_RHO(2000, 30000000, TRUE)

Expected output:

32.1146

Python Code

Show Code

from chemicals.iapws import iapws97_rho as chemicals_iapws97_rho

def iapws97_rho(T, P, use_ninety_five_boundary=False):
    """
    Compute water density from temperature and pressure using IAPWS-97.

    See: https://chemicals.readthedocs.io/chemicals.iapws.html#chemicals.iapws.iapws97_rho

    This example function is provided as-is without any representation of accuracy.

    Args:
        T (float): Water temperature (K).
        P (float): Water pressure (Pa).
        use_ninety_five_boundary (bool, optional): Use IAPWS-95 vapor-pressure boundary instead of IF-97 boundary (-). Default is False.

    Returns:
        float: Water density at the specified state (kg/m^3).
    """
    try:
        return chemicals_iapws97_rho(T, P, use_95_boundary=use_ninety_five_boundary)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

T *

Water temperature (K).

P *

Water pressure (Pa).

use_ninety_five_boundary

Use IAPWS-95 vapor-pressure boundary instead of IF-97 boundary (-).