Docs @ a8c72a1

Author: MFC Action

documentation/architecture.html

@@ -427,7 +427,7 @@ <h1 class="doxsection"><a class="anchor" id="autotoc_md13"></a>
 <li><b>Add the module to <span class="tt">docs/module_categories.json</span></b> so it appears in this page</li>
 </ol>
 <p>Follow the pattern of existing modules like <span class="tt">m_body_forces</span> (simple) or <span class="tt">m_viscous</span> (more involved) as a template.</p>
-<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
+<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-19</div> </div></div><!-- contents -->
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documentation/case.html

@@ -1377,10 +1377,18 @@ <h3 class="doxsection"><a class="anchor" id="autotoc_md34"></a>
 <tr class="markdownTableRowOdd">
 <td class="markdownTableBodyRight"><span class="tt">chem_params%transport_model</span>  </td><td class="markdownTableBodyCenter">Integer  </td><td class="markdownTableBodyLeft">Methodology for calculating the diffusion coefficients  </td></tr>
 <tr class="markdownTableRowEven">
+<td class="markdownTableBodyRight"><span class="tt">chem_params%reaction_substeps</span>  </td><td class="markdownTableBodyCenter">Integer  </td><td class="markdownTableBodyLeft">Sub-steps for operator-split reaction integration (0 = off)  </td></tr>
+<tr class="markdownTableRowOdd">
+<td class="markdownTableBodyRight"><span class="tt">chem_params%adap_substeps</span>  </td><td class="markdownTableBodyCenter">Logical  </td><td class="markdownTableBodyLeft">Per-rank adaptive sub-step count driven by local stiffness  </td></tr>
+<tr class="markdownTableRowEven">
+<td class="markdownTableBodyRight"><span class="tt">chem_params%reaction_substeps_max</span>  </td><td class="markdownTableBodyCenter">Integer  </td><td class="markdownTableBodyLeft">Sub-step ceiling when <span class="tt">adap_substeps</span> is enabled  </td></tr>
+<tr class="markdownTableRowOdd">
 <td class="markdownTableBodyRight"><span class="tt">cantera_file</span>  </td><td class="markdownTableBodyCenter">String  </td><td class="markdownTableBodyLeft">Cantera-format mechanism file (e.g., .yaml)  </td></tr>
 </table>
 <ul>
 <li><span class="tt">chem_params%transport_model</span> specifies the methodology for calculating diffusion coefficients and other transport properties, <span class="tt">1</span> for mixture-average, <span class="tt">2</span> for Unity-Lewis</li>
+<li><span class="tt">chem_params%reaction_substeps</span> controls how the reaction source is integrated. With <span class="tt">0</span> (default) the net production rates are added to the flow right-hand side and advanced by the flow time stepper (fine for hydrogen). With a value <span class="tt">&gt; 0</span>, the reaction is instead integrated by operator splitting after each flow update: every cell's constant-density, constant-internal-energy reactor is advanced over the timestep with that many sub-steps of an <b>α-QSS</b> (quasi-steady-state) integrator — a matrix-free, Jacobian-free predictor–corrector (Mott/CHEMEQ2) that splits the net rate into creation/destruction parts and applies a Padé α-weighting, so it stays stable on stiff mechanisms where an explicit source diverges. This decouples the (often much faster) chemical timescale from the flow timestep and is required for stiff mechanisms — e.g. hydrocarbons such as GRI-Mech methane, which otherwise diverge on the first step</li>
+<li><span class="tt">chem_params%adap_substeps</span> (default <span class="tt">F</span>) makes each rank choose its α-QSS sub-step count per flow step from the largest chemical stiffness among its own cells: the count sits at <span class="tt">reaction_substeps</span> (the floor) in inert or burned gas and rises toward <span class="tt">reaction_substeps_max</span> (the ceiling) only across the reaction front. It uses no MPI collectives. When enabled, <span class="tt">reaction_substeps &gt;= 1</span> and <span class="tt">reaction_substeps_max &gt;= reaction_substeps</span> are required</li>
 <li><span class="tt">cantera_file</span> specifies the chemical mechanism file. If the file is part of the standard Cantera library, only the filename is required. Otherwise, the file must be located in the same directory as your <span class="tt">case.py</span> file</li>
 </ul>
 <h3 class="doxsection"><a class="anchor" id="autotoc_md35"></a>

documentation/case_constraints.html

@@ -1462,7 +1462,7 @@ <h2 class="doxsection"><a class="anchor" id="physics-warnings"></a>
 </table>
 <hr  />
 <p>💡 <b>Tip:</b> If you encounter a validation error, check the relevant section above or review <a href="https://github.com/MFlowCode/MFC/blob/master/toolchain/mfc/case_validator.py"><span class="tt">case_validator.py</span></a> for complete validation logic.</p>
-<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
+<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-19</div> </div></div><!-- contents -->
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documentation/cli-reference.html

@@ -999,7 +999,7 @@ <h3 class="doxsection"><a class="anchor" id="autotoc_md82"></a>
 <h3 class="doxsection"><a class="anchor" id="autotoc_md83"></a>
 Debug Logging (<span class="tt">-d, --debug-log</span>)</h3>
 <p>Enables debug logging for the Python toolchain (mfc.sh internals). This is for troubleshooting the build system, not the MFC simulation code.</p>
-<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
+<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-19</div> </div></div><!-- contents -->
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documentation/examples.html

@@ -630,7 +630,7 @@ <h2 class="doxsection"><a class="anchor" id="autotoc_md313"></a>
 <h3 class="doxsection"><a class="anchor" id="autotoc_md314"></a>
 Liutex visualization at transitional state</h3>
 <p><img src="result-3D_turb_mixing-example.png" alt="" height="400" class="inline"/></p>
-<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
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documentation/parameters.html

@@ -165,7 +165,7 @@
 </blockquote>
 <h2 class="doxsection"><a class="anchor" id="autotoc_md378"></a>
 Overview</h2>
-<p>MFC supports <b>3,775</b> case parameters organized into families.</p>
+<p>MFC supports <b>3,778</b> case parameters organized into families.</p>
 <p><b>Quick search:</b> Use <span class="tt">./mfc.sh params &lt;query&gt;</span> to search parameters from the command line.</p>
 <h2 class="doxsection"><a class="anchor" id="autotoc_md379"></a>
 Parameter Families</h2>
@@ -225,7 +225,7 @@ <h2 class="doxsection"><a class="anchor" id="autotoc_md379"></a>
 <tr class="markdownTableRowEven">
 <td class="markdownTableBodyNone"><a class="el" href="#stl_models" title="stl_models">stl_models</a>  </td><td class="markdownTableBodyNone">8  </td><td class="markdownTableBodyNone"></td></tr>
 <tr class="markdownTableRowOdd">
-<td class="markdownTableBodyNone"><a class="el" href="#chem_params" title="chem_params">chem_params</a>  </td><td class="markdownTableBodyNone">4  </td><td class="markdownTableBodyNone">Chemistry model parameters  </td></tr>
+<td class="markdownTableBodyNone"><a class="el" href="#chem_params" title="chem_params">chem_params</a>  </td><td class="markdownTableBodyNone">7  </td><td class="markdownTableBodyNone">Chemistry model parameters  </td></tr>
 <tr class="markdownTableRowEven">
 <td class="markdownTableBodyNone"><a class="el" href="#ib_airfoil" title="ib_airfoil">ib_airfoil</a>  </td><td class="markdownTableBodyNone">4  </td><td class="markdownTableBodyNone"></td></tr>
 <tr class="markdownTableRowOdd">
@@ -1082,17 +1082,23 @@ <h3 class="doxsection"><a class="anchor" id="autotoc_md428"></a>
 <h2 class="doxsection"><a class="anchor" id="chem_params"></a>
 chem_params</h2>
 <p><em>Chemistry model parameters</em></p>
-<p><b>4 parameters</b></p>
+<p><b>7 parameters</b></p>
 <table class="markdownTable">
 <tr class="markdownTableHead">
 <th class="markdownTableHeadNone">Parameter  </th><th class="markdownTableHeadNone">Type  </th><th class="markdownTableHeadNone">Description  </th><th class="markdownTableHeadNone">Constraints  </th></tr>
 <tr class="markdownTableRowOdd">
-<td class="markdownTableBodyNone"><span class="tt">chem_params%diffusion</span>  </td><td class="markdownTableBodyNone">Logical (T/F)  </td><td class="markdownTableBodyNone">Enable species diffusion for chemistry  </td><td class="markdownTableBodyNone">Isothermal In (<span class="tt">bc_xisothermal_in</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.; Isothermal Out (<span class="tt">bc_xisothermal_out</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.; Isothermal In (<span class="tt">bc_yisothermal_in</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.  </td></tr>
+<td class="markdownTableBodyNone"><span class="tt">chem_params%adap_substeps</span>  </td><td class="markdownTableBodyNone">Logical (T/F)  </td><td class="markdownTableBodyNone">Chemistry parameter: adap_substeps  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
 <tr class="markdownTableRowEven">
+<td class="markdownTableBodyNone"><span class="tt">chem_params%diffusion</span>  </td><td class="markdownTableBodyNone">Logical (T/F)  </td><td class="markdownTableBodyNone">Enable species diffusion for chemistry  </td><td class="markdownTableBodyNone">Isothermal In (<span class="tt">bc_xisothermal_in</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.; Isothermal Out (<span class="tt">bc_xisothermal_out</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.; Isothermal In (<span class="tt">bc_yisothermal_in</span>) requires both <span class="tt">chemistry</span>='T' and <span class="tt">chem_paramsdiffusion</span>='T' to calculate heat conduction.  </td></tr>
+<tr class="markdownTableRowOdd">
 <td class="markdownTableBodyNone"><span class="tt">chem_params%gamma_method</span>  </td><td class="markdownTableBodyNone">Integer  </td><td class="markdownTableBodyNone">Gamma calculation method (1=formulation, 2=cp/cv ratio)  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
+<tr class="markdownTableRowEven">
+<td class="markdownTableBodyNone"><span class="tt">chem_params%reaction_substeps</span>  </td><td class="markdownTableBodyNone">Integer  </td><td class="markdownTableBodyNone">Chemistry parameter: reaction_substeps  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
 <tr class="markdownTableRowOdd">
-<td class="markdownTableBodyNone"><span class="tt">chem_params%reactions</span>  </td><td class="markdownTableBodyNone">Logical (T/F)  </td><td class="markdownTableBodyNone">Enable chemical reactions  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
+<td class="markdownTableBodyNone"><span class="tt">chem_params%reaction_substeps_max</span>  </td><td class="markdownTableBodyNone">Integer  </td><td class="markdownTableBodyNone">Chemistry parameter: reaction_substeps_max  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
 <tr class="markdownTableRowEven">
+<td class="markdownTableBodyNone"><span class="tt">chem_params%reactions</span>  </td><td class="markdownTableBodyNone">Logical (T/F)  </td><td class="markdownTableBodyNone">Enable chemical reactions  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
+<tr class="markdownTableRowOdd">
 <td class="markdownTableBodyNone"><span class="tt">chem_params%transport_model</span>  </td><td class="markdownTableBodyNone">Integer  </td><td class="markdownTableBodyNone">Transport model selection for chemistry  </td><td class="markdownTableBodyNone">Chemistry parameter  </td></tr>
 </table>
 <hr  />
@@ -1715,7 +1721,7 @@ <h2 class="doxsection"><a class="anchor" id="autotoc_md447"></a>
 <div class="line"> </div>
 <div class="line"># Filter by type</div>
 <div class="line">./mfc.sh params -t real weno</div>
-</div><!-- fragment --><div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
+</div><!-- fragment --><div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-19</div> </div></div><!-- contents -->
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documentation/physics_constraints.html

@@ -674,7 +674,7 @@ <h3 class="doxsection"><a class="anchor" id="autotoc_md501"></a>
 <li><code class="f90l">patch_icpp(i)%</code><code class="f90r">hcid</code>=hcid requires <span class="tt">files_dir</span> to be set</li>
 <li><code class="f90l">patch_icpp(i)%</code><code class="f90r">hcid</code>=hcid requires <span class="tt">file_extension</span> to be set</li>
 </ul>
-<div style="text-align:center; font-size:0.75rem; color:#888; padding:16px 0 0;">Page last updated: 2026-07-18</div> </div></div><!-- contents -->
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post_process/doxygen_crawl.html

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post_process/functions.html

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post_process/functions_r.html

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