.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/thermodynamics/properties/plot_10_iapws_if97_region5.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_thermodynamics_properties_plot_10_iapws_if97_region5.py>`
        to download the full example code or to run this example in your browser via JupyterLite.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_thermodynamics_properties_plot_10_iapws_if97_region5.py:


IAPWS-IF97 region 5: steam in gas turbines (1997)
=================================================

Above 800 °C steam leaves the range of power-station boilers. It enters
gas-turbine combustors and steam-injected turbines, where water is sprayed
into the hot gas. IF97's region 5 covers 1073.15 K to 2273.15 K, at pressures
up to 50 MPa since the 2007 revision. Like region 2 it is a dimensionless
Gibbs function, of :math:`p/1\,\mathrm{MPa}` and :math:`1000\,\mathrm{K}/T`.
:func:`~engineeringkit.thermodynamics.steam_properties` switches to it
automatically and accepts arrays of states.

.. GENERATED FROM PYTHON SOURCE LINES 15-20

.. code-block:: Python

    import matplotlib.pyplot as plt
    import numpy as np

    from engineeringkit.thermodynamics import steam_properties








.. GENERATED FROM PYTHON SOURCE LINES 21-26

The release's verification values
----------------------------------

IF97 Table 42 lists three states; the implementation matches them to nine
digits.

.. GENERATED FROM PYTHON SOURCE LINES 26-34

.. code-block:: Python


    table = [(1500.0, 0.5e6, 5219.76855, 9.65408875), (1500.0, 30e6, 5167.23514, 7.72970133), (2000.0, 30e6, 6571.22604, 8.53640523)]
    states = steam_properties([p for _, p, _, _ in table], [T for T, _, _, _ in table])
    for (T, p, h, s), hh, ss in zip(table, states.h, states.s):
        print(f"{T:.0f} K, {p / 1e6:4.1f} MPa: h = {hh / 1e3:.5f} kJ/kg (table {h}), s = {ss / 1e3:.8f} kJ/(kg K) (table {s})")
    assert np.all(states.region == 5)
    np.testing.assert_allclose(states.h / 1e3, [h for *_, h, _ in table], rtol=1e-8)





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    1500 K,  0.5 MPa: h = 5219.76855 kJ/kg (table 5219.76855), s = 9.65408875 kJ/(kg K) (table 9.65408875)
    1500 K, 30.0 MPa: h = 5167.23514 kJ/kg (table 5167.23514), s = 7.72970133 kJ/(kg K) (table 7.72970133)
    2000 K, 30.0 MPa: h = 6571.22604 kJ/kg (table 6571.22604), s = 8.53640523 kJ/(kg K) (table 8.53640523)




.. GENERATED FROM PYTHON SOURCE LINES 35-41

Steam as a nearly ideal gas
---------------------------

Arrays sweep a whole isobar in one call. Across the 1073.15 K boundary
between regions 2 and 5 the specific heat continues smoothly, and at these
temperatures steam is close to an ideal gas, :math:`pv/RT \approx 1`.

.. GENERATED FROM PYTHON SOURCE LINES 41-56

.. code-block:: Python


    T = np.linspace(600.0, 2273.15, 200)
    fig, ax = plt.subplots(figsize=(6, 3.5))
    for p in (0.1e6, 5e6, 30e6):
        st = steam_properties(p, T)
        ax.plot(T - 273.15, st.cp / 1e3, label=f"{p / 1e6:g} MPa")
    ax.axvline(800.0, color="gray", ls=":")
    ax.set(xlabel="temperature [°C]", ylabel="c_p [kJ/(kg K)]", title="Superheated steam, IF97 regions 2 and 5")
    ax.legend()
    fig.tight_layout()
    z = 0.5e6 * steam_properties(0.5e6, 2000.0).v / (461.526 * 2000.0)
    print(f"compressibility of steam at 0.5 MPa and 2000 K: {z:.5f}")
    assert abs(z - 1) < 1e-3

    plt.show()



.. image-sg:: /api/gallery/thermodynamics/properties/images/sphx_glr_plot_10_iapws_if97_region5_001.png
   :alt: Superheated steam, IF97 regions 2 and 5
   :srcset: /api/gallery/thermodynamics/properties/images/sphx_glr_plot_10_iapws_if97_region5_001.png
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    compressibility of steam at 0.5 MPa and 2000 K: 1.00019





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.213 seconds)


.. _sphx_glr_download_api_gallery_thermodynamics_properties_plot_10_iapws_if97_region5.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: lite-badge

      .. image:: images/jupyterlite_badge_logo.svg
        :target: ../../../../lite/lab/index.html?path=api/gallery/thermodynamics/properties/plot_10_iapws_if97_region5.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_10_iapws_if97_region5.ipynb <plot_10_iapws_if97_region5.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_10_iapws_if97_region5.py <plot_10_iapws_if97_region5.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_10_iapws_if97_region5.zip <plot_10_iapws_if97_region5.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_