Update single droplet evaporation documentation

Docs/sphinx/Spray.rst

@@ -226,6 +226,27 @@ The procedure is as follows for updating the spray droplet:
 
     :math:`N_{d}` is the number of droplets per computational parcel, and :math:`V_{\rm{cell}}` is the volume for the cell of interest. Note that the cell volume can vary depending on AMR level and if an EB is present.
 
+
+.. warning::
+
+   **Dimensional Assumptions in the Spray Model**
+
+   The spray model assumes spherically symmetric droplets and is inherently three-dimensional. 
+   For two-dimensional simulations, the domain is treated as one cell wide in the :math:`z`-direction, 
+   with :math:`L_z = \Delta x`, so the volume in the gas-phase source terms is:
+
+   .. math::
+
+      V_{\rm{cell}} = \Delta x \, \Delta y \, \Delta x
+
+   For nominally single droplet cases, this effectively places an infinite array of droplets spaced :math:`\Delta x` apart in :math:`z`, 
+   exaggerating Stefan flow in the :math:`x`- and :math:`y`-directions and omitting flow in :math:`z`. While this has minimal impact on 
+   droplet diameter or temperature, it can distort the surrounding gas-phase flow, especially for low :math:`\text{Re}_d`.
+
+   For such cases, fully three-dimensional simulations are recommended.
+
+
+
 Spray Flags and Inputs
 ======================
 
@@ -303,7 +324,7 @@ Spray Flags and Inputs
 
     particles.SP_psat = 4.07857 1501.268 -78.67 1.E5
 
-  where the numbers represent :math:`a`, :math:`b`, :math:`c`, and :math:`d`, respectively in:
+  where the numbers represent coefficients :math:`a`, :math:`b`, :math:`c`, and unit conversion :math:`d`, respectively in:
 
   .. math::
      p_{\rm{sat}}(T) = d 10^{a - b / (T + c)}
@@ -442,60 +463,75 @@ one can use ``spray.jet_dpm.trans_matrix`` and ``spray.jet_dpm.translation`` to
    :align: center
    :figwidth: 60%
 
+.. _spray_validation:
+
 Spray Validation
 ================
 
 Single Droplet Tests
 --------------------
 
-Single droplet tests are performed and compared with computational or experimental results published in literature. These tests are setup in ``PeleProduction/PeleMPruns/single_drop_test``. To run a test case, simply open ``Validate.py`` and set the case name from the table below ::
+Single droplet tests are performed in 2D with PeleLMeX and compared with experimental results published in literature. These tests are setup in ``PeleLMeX/Exec/RegTests/SprayEvap``. To run a test case, simply open ``Validate.py`` and set the case name from the table below, for example ::
 
-  case = TestCaseName()
+  case = WongLin()
 
-then do ``python Validate.py``.
+then run ``python Validate.py``.
 The following table details the parameters of each test:
 
 .. table::
 
-   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+
-   |Test Case Name | :math:`T_g` [K] |:math:`p_g` [bar]|:math:`T_d` [K]  |:math:`d_d` [um] | :math:`\Delta u` [m/s]|Ref              |
-   |               |                 |                 |                 |                 |                       |                 |
-   +===============+=================+=================+=================+=================+=======================+=================+
-   |``Tonini_4_33``|1000             |1                |300              |200              |6.786                  |[#ton]_          |
-   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+
-   |``Abramzon``   |1500             |10               |300              |100              |15                     |[#abram]_        |
-   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+
-   |``Daif``       |348              |1                |294              |1334             |3.10                   |[#daif]_         |
-   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+
-   |``RungeHep``   |273              |1                |272              |500-570          |2.5                    |[#runge]_        |
-   |``RungeDec``   |                 |                 |                 |                 |                       |                 |
-   |``RungeMix``   |                 |                 |                 |                 |                       |                 |
-   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+
-
-.. figure:: /Visualization/ton_res.png
+   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+-----------------+
+   |Test Name      | :math:`T_g` [K] |:math:`p_g` [bar]|:math:`T_d` [K]  |:math:`d_d` [um] | :math:`\Delta u` [m/s]|Fuel             |Ref              |
+   |               |                 |                 |                 |                 |                       |                 |                 |
+   +===============+=================+=================+=================+=================+=======================+=================+=================+
+   |``Nomura``     |471              |1                |298              |700              |0.0                    |heptane          |[#nomura]_       |
+   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+-----------------+
+   |``WongLin``    |1000             |1.01325          |315              |1961             |0.385                  |decane           |[#wonglin]_      |
+   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+-----------------+
+   |``Daif``       |348              |1.01325          |291              |1334             |3.1                    |heptane/decane   |[#daif]_         |
+   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+-----------------+
+   |``RungeHep``,  |272              |1.01325          |272              |570-594          |2.5                    |heptane,         |[#runge]_        |
+   |``RungeDec``,  |                 |                 |                 |                 |                       |decane,          |                 |
+   |``RungeMix``   |                 |                 |                 |                 |                       |mix              |                 |
+   +---------------+-----------------+-----------------+-----------------+-----------------+-----------------------+-----------------+-----------------+
+
+
+.. figure:: /Visualization/nomura_res_2025.png
+   :align: center
+   :figwidth: 40%
+
+   Heptane droplet diameter comparisons with Nomura et al. [#nomura]_
+
+.. figure:: /Visualization/wonglin_res_2025.png
    :align: center
    :figwidth: 80%
 
-   Droplet diameter, temperature, and n-octane mass fraction comparisons with Figure 4.33 in [#ton]_
+   Decane droplet diameter and temperature comparisons with Wong & Lin [#wonglin]_
 
-.. figure:: /Visualization/abram_res.png
+.. figure:: /Visualization/daif_res_2025.png
    :align: center
    :figwidth: 80%
 
-   Droplet diameter and temperature comparisons with [#abram]_
+   Binary mixture of heptane and decane droplet diameter and temperature comparisons with Daı̈f et al. [#daif]_
 
-.. figure:: /Visualization/daif_res.png
+.. figure:: /Visualization/runge_simple_res_2025.png
    :align: center
    :figwidth: 80%
 
-   Droplet diameter and temperature comparisons with [#daif]_
+   Droplet evaporation of heptane, decane, and a binary mixture of heptane and decane compared to experimental measurements from with Runge et al. [#runge]_
 
-.. [#ton] "Fuel spray modeling in direct-injection diesel and gasoline engines", S. Tonini, Dissertation, City University London (2006)
+
+.. [#ton] "Fuel spray modeling in direct-injection diesel and gasoline engines", S. Tonini, Dissertation, City University London (2006), url: `https://openaccess.city.ac.uk/id/eprint/8486/ <https://openaccess.city.ac.uk/id/eprint/8486/>`_.
 
 .. [#abram] "Droplet vaporization model for spray combustion calculations", B. Abramzon and W. A. Sirignano, Int. J. Heat Mass Transfer, Vol. 32, No. 9, pp. 1605-1618 (1989)
 
-.. [#daif] "Comparison of multicomponent fuel droplet vaporization experiments in forced convection with the Sirignano model", A. Daı̈f and M. Bouaziz and X. Chesneau and A. Ali Chérif, Exp. Therm. Fluid Sci., Vol. 18, No. 4, pp. 282-290, Issn 0894-1777 (1998)
+.. [#Ge] "Development of a CPU/GPU portable software library for Lagrangian-Eulerian simulations of liquid sprays", W. Ge and R. Sankaran and J. H. Chen, Int. J. Multiph. Flow, Vol. 128 (2020), doi: `10.1016/j.ijmultiphaseflow.2020.103293 <https://doi.org/10.1016/j.ijmultiphaseflow.2020.103293>`_.
+
+.. [#nomura] “Experimental study on high-pressure droplet evaporation using microgravity conditions”, H. Nomura and Y. Ujiie and H. J. Rath and J. Sato and M. Kono, Symposium (International) on Combustion, vol. 26, no. 1, pp. 1267–1273 (1996), doi: `10.1016/S0082-0784(96)80344-4 <https://doi.org/10.1016/S0082-0784(96)80344-4>`_.
+
+.. [#wonglin] “Internal temperature distributions of droplets vaporizing in high-temperature convective flows”, S.-C. Wong and A.-C. Lin, J. Fluid Mech., vol. 237, pp. 671–687 (1992), doi: `10.1017/S0022112092003574 <https://doi.org/10.1017/S0022112092003574>`_.  
+
+.. [#daif] "Comparison of multicomponent fuel droplet vaporization experiments in forced convection with the Sirignano model", A. Daı̈f and M. Bouaziz and X. Chesneau and A. Ali Chérif, Exp. Therm. Fluid Sci., Vol. 18, No. 4, pp. 282-290, Issn 0894-1777 (1998), doi: `10.1016/S0894-1777(98)10035-3 <https://doi.org/10.1016/S0894-1777(98)10035-3>`_.
 
-.. [#runge] "Low-temperature vaporization of JP-4 and JP-8 fuel droplets", T. Runge and M. Teske and C. E. Polymeropoulos, At. Sprays, Vol. 8, pp. 25-44 (1998)
+.. [#runge] "Low-temperature vaporization of JP-4 and JP-8 fuel droplets", T. Runge and M. Teske and C. E. Polymeropoulos, At. Sprays, Vol. 8, pp. 25-44 (1998), doi: `10.1615/AtomizSpr.v8.i1.20 <https://doi.org/10.1615/AtomizSpr.v8.i1.20>`_.
 
-.. [#Ge] "Development of a CPU/GPU portable software library for Lagrangian-Eulerian simulations of liquid sprays", W. Ge and R. Sankaran and J. H. Chen, Int. J. Multiph. Flow, Vol. 128 (2020)