From 980fec844b281259f5d3ad34fded8dfdb6cb68a6 Mon Sep 17 00:00:00 2001 From: Ray Speth Date: Mon, 8 Jan 2024 21:11:26 -0500 Subject: [PATCH] [Doc] Improve wording about automatic third-body detection Fixes Cantera/cantera-website#262 --- doc/sphinx/reference/kinetics/reaction-rates.md | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/doc/sphinx/reference/kinetics/reaction-rates.md b/doc/sphinx/reference/kinetics/reaction-rates.md index 14a62fd22f..becff62574 100644 --- a/doc/sphinx/reference/kinetics/reaction-rates.md +++ b/doc/sphinx/reference/kinetics/reaction-rates.md @@ -25,9 +25,10 @@ parameterizations such as the [modified Arrhenius](sec-arrhenius-rate) form. :class: tip An elementary reaction with an Arrhenius reaction rate can be defined in the YAML format using the [`elementary`](sec-yaml-elementary) reaction `type`, or by omitting the -reaction `type` entry, as it represents the default. In case the `type` entry is omitted -and a species occurs on both sides of the reaction equation, Cantera infers that the -reaction type is [`three-body`](sec-yaml-three-body). +reaction `type` entry, as it represents the default. An exception to this default is +when the same species occurs on both sides of the reaction equation, in which case the +reaction is treated as a +[three-body reaction for a specific collider](sec-three-body-specific-collider). ``` (sec-three-body-reaction)= @@ -69,6 +70,9 @@ The rate coefficient $k_f(T)$ may be implemented using any rate parameterization supported by Cantera, not just the modified Arrhenius form. ::: +(sec-three-body-specific-collider)= +### Collider-specific rate parameterizations + Sometimes, accounting for a particular third body's collision efficiency may require an alternate set of rate parameters entirely. In this case, two reactions are written: @@ -79,7 +83,8 @@ $$ $$ where the third-body efficiency for C in the first reaction should be explicitly set to -zero. +zero. For the second reaction, the efficiencies will automatically be set to one for C +and zero for all other colliders. ```{admonition} YAML Usage :class: tip