{"id":361986,"date":"2024-04-12T15:16:03","date_gmt":"2024-04-12T15:16:03","guid":{"rendered":"\/forum\/forums\/topic\/kinetic-mechanisms-and-arrhenius-equation-parameters-in-ansys-fluent\/"},"modified":"2024-04-12T15:16:03","modified_gmt":"2024-04-12T15:16:03","slug":"kinetic-mechanisms-and-arrhenius-equation-parameters-in-ansys-fluent","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/kinetic-mechanisms-and-arrhenius-equation-parameters-in-ansys-fluent\/","title":{"rendered":"Kinetic Mechanisms and Arrhenius Equation Parameters in ANSYS Fluent"},"content":{"rendered":"

Hello,<\/span><\/p>\n

I am currently work in a project that necessitates the implementation of kinetic mechanisms in ANSYS Fluent. My objective is to refine the reaction mechanism to a simplified one-step reaction model by adjusting the Arrhenius equation parameters. This simplification is crucial for approximating the behavior of a complex system but also for computational cost.<\/span><\/p>\n

 <\/p>\n

Additionally, I am tasked with modeling an experimental setup that includes a constant UV reactor.<\/span><\/p>\n

<\/span><\/p>\n

 <\/p>\n

To this end, I have constructed a model with the following characteristics:<\/span><\/p>\n

•<\/span>A cubic volume with a 1 cm³ block.<\/span><\/span><\/div>\n
•<\/span>Boundary conditions define a wall interface.<\/span><\/span><\/div>\n
•<\/span>The system initializes at 2400K.<\/span><\/span><\/div>\n
•<\/span>The absolute pressure is set at 38 Bar.<\/span><\/span><\/div>\n
 <\/div>\n

My method involves plotting the mass to verify mass conservation. However, I have observed discrepancies when altering the Arrhenius parameters, particularly changes that affect the mass in the system. These discrepancies are a concern as they indicate potential issues with the reaction rate or mass conservation in the model.<\/span><\/p>\n

 <\/p>\n

Attached a data sets with varying parameters and the mass evolution over time<\/span><\/p>\n

 <\/p>\n

 <\/p>\n\n\n<\/colgroup>\n\n\n\n\n\n
\n

Parameters<\/span><\/p>\n<\/td>\n

\n

Sim 1<\/span><\/p>\n<\/td>\n

\n

Sim 2<\/span><\/p>\n<\/td>\n

\n

Sim 3<\/span><\/p>\n<\/td>\n

\n

Sim 4<\/span><\/p>\n<\/td>\n<\/tr>\n

\n

A<\/span><\/p>\n<\/td>\n

\n

6068000<\/span><\/p>\n<\/td>\n

\n

6068000<\/span><\/p>\n<\/td>\n

\n

6.0 E8<\/span><\/p>\n<\/td>\n

\n

6.0 E8<\/span><\/p>\n<\/td>\n<\/tr>\n

\n

n<\/span><\/p>\n<\/td>\n

\n

0.1<\/span><\/p>\n<\/td>\n

\n

0.1<\/span><\/p>\n<\/td>\n

\n

2.66e-7<\/span><\/p>\n<\/td>\n

\n

0<\/span><\/p>\n<\/td>\n<\/tr>\n

\n

Ea<\/span><\/p>\n<\/td>\n

\n

1.825e+08<\/span><\/p>\n<\/td>\n

\n

1.825e+07<\/span><\/p>\n<\/td>\n

\n

1.80 E8<\/span><\/p>\n<\/td>\n

\n

9.125e+07<\/span><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

<\/span><\/p>\n

I would greatly appreciate your insight into the following questions:<\/span><\/p>\n

1. <\/span>Are there known issues or typical challenges when adjusting Arrhenius equation parameters in Fluent that could lead to mass discrepancies?<\/span><\/span><\/div>\n
2.<\/span> Could you provide guidance or recommendations on best practices for modifying these parameters to maintain mass conservation?<\/span><\/span><\/div>\n
3. <\/span>Is there any additional documentation or resources that could assist me in troubleshooting and resolving these discrepancies?<\/span><\/span><\/div>\n
 <\/div>\n

Thank you for your time and assistance.<\/span><\/p>\n

 <\/p>\n

Ghislain<\/span><\/p>\n","protected":false},"template":"","class_list":["post-361986","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t