IAPWS95_T

This function inverts the IAPWS-95 formulation to estimate water temperature from pressure and density. It is useful for state reconstruction when pressure and density are measured inputs.

The inverse state mapping is:

T = f^{-1}(P, \rho)

where P is pressure and \rho is mass density.

Excel Usage

=IAPWS95_T(P, rho)

• P (float, required): Water pressure (Pa).
• rho (float, required): Water mass density (kg/m^3).

Returns (float): Water temperature corresponding to the specified pressure and density (K).

Example 1: Invert compressed-water state

Inputs:

P	rho
1000000	995

Excel formula:

=IAPWS95_T(1000000, 995)

Expected output:

306.462

Example 2: Moderate pressure dense state inversion

Inputs:

P	rho
5000000	975

Excel formula:

=IAPWS95_T(5000000, 975)

Expected output:

351.482

Example 3: Low density vapor-side inversion

Inputs:

P	rho
200000	1.5

Excel formula:

=IAPWS95_T(200000, 1.5)

Expected output:

350.651

Example 4: Near critical dense inversion

Inputs:

P	rho
22000000	350

Excel formula:

=IAPWS95_T(22000000, 350)

Expected output:

646.862

Python Code

Show Code

from chemicals.iapws import iapws95_T as chemicals_iapws95_t

def iapws95_t(P, rho):
    """
    Compute water temperature from pressure and density using IAPWS-95.

    See: https://chemicals.readthedocs.io/chemicals.iapws.html#chemicals.iapws.iapws95_T

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

    Args:
        P (float): Water pressure (Pa).
        rho (float): Water mass density (kg/m^3).

    Returns:
        float: Water temperature corresponding to the specified pressure and density (K).
    """
    try:
        return chemicals_iapws95_t(P, rho)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

P *

Water pressure (Pa).

rho *

Water mass density (kg/m^3).