Add Sato option from MR 1429 (!113)

docs/source_docs/refs.bib

@@ -464,6 +464,15 @@ doi = {https://doi.org/10.1016/j.jcp.2022.111305},
   pages = {267}
 }
 
+@article{sato81,
+  author = {Sato, Y. and Sadatomi, M.},
+  title = {Momentum and heat transfer in two-phase bubble flow - I. Theory},
+  journal = {International Journal of Multiphase Flow},
+  year = {1981},
+  volume = {7},
+  pages = {167-177}
+}
+
 @article{Sch33,
   author = {Schiller, L. and Naumann, A. },
   title = {A drag coefficient correlation},

docs/source_docs/user_guide/inputs/fluid_model.rst

@@ -21,6 +21,8 @@ a single fluid; therefore, it is common to name the fluid ``fluid``. This is ill
 
 .. |Reid_4parm_Eq| replace:: :math:`\mu(T) = A\exp{\left( \frac{B}{T} + CT + DT^2 \right)}`
 
+.. |Sato_Eq| replace:: :math:`\mu^* = 1 + C d_s \rho \mu_{mol} \left|\boldsymbol{u} - \boldsymbol{u_s}\right|`
+
 +--------------------------------------------+------------------------------------------------------------+--------+----------+
 |                                            | Description                                                |  Type  | Default  |
 +============================================+============================================================+========+==========+
@@ -104,6 +106,10 @@ a single fluid; therefore, it is common to name the fluid ``fluid``. This is ill
 |                                            |                                                            |        |          |
 |                                            |      :math:`\mu^*=e^{2.5(1/(1-\varepsilon_s)^c-1)/c}`      |        |          |
 |                                            |                                                            |        |          |
+|                                            | * ``Sato`` :cite:p:`sato81`                                |        |          |
+|                                            |                                                            |        |          |
+|                                            |      |Sato_Eq|                                             |        |          |
+|                                            |                                                            |        |          |
 +--------------------------------------------+------------------------------------------------------------+--------+----------+
 | viscosity.suspension.Brinkman.constant     | Constant for exponent in Brinkman suspension expression.   | Real   | None     |
 |                                            |                                                            |        |          |
@@ -121,6 +127,9 @@ a single fluid; therefore, it is common to name the fluid ``fluid``. This is ill
 |                                            |                                                            |        |          |
 |                                            | A value is required when using the model ``ChengLaw``.     |        |          |
 +--------------------------------------------+------------------------------------------------------------+--------+----------+
+| viscosity.suspension.Sato.constant         | Constant for Sato suspension expression.                   | Real   | 0.65     |
+|                                            |                                                            |        |          |
++--------------------------------------------+------------------------------------------------------------+--------+----------+
 | viscosity.max_effective_factor             | Max limit of the effective viscosity as a factor of the    | Real   | 1.e6     |
 |                                            | molecular viscosity                                        |        |          |
 |                                            |                                                            |        |          |

docs/source_docs/user_guide/inputs/output/plotfiles.rst

@@ -56,8 +56,6 @@ The following inputs must be preceded by "mfix." and control what variables will
 +---------------------+-----------------------------------------------------------------------+-------------+-----------+
 | plt_mu_g            | Save fluid molecular viscosity to plot file                           |    Int      | 0         |
 +---------------------+-----------------------------------------------------------------------+-------------+-----------+
-| plt_mu_g_eff        | Save fluid effective viscosity to plot file                           |    Int      | 0         |
-+---------------------+-----------------------------------------------------------------------+-------------+-----------+
 | plt_diveu           | Save div(ep_g . u) to plot file                                       |    Int      | 0         |
 +---------------------+-----------------------------------------------------------------------+-------------+-----------+
 | plt_volfrac         | Save Eulerian grid volume fraction (from cut cells) to plot file      |    Int      | 0         |