Arun Pattanashetti It could be due to unstructured mesh or inappropriate boundary conditions applied.

Thank you mam, but when I start with non reacting simulation it is working fine, when I switch it to reacting mode solution diverges. If the BC's are wrong than it would have not worked for non reacting case as well then...

Geethu Varghese Thank you mam, but when I start with nonreacting simulation it is working fine, when I switch it to reacting mode solution diverges. If the BC's are wrong then it would have not worked for nonreacting cases as well then..

Arun Pattanashetti , what kind of geometry is it?

I recommend you to check material properties of species. You can also have a check on mesh quality.

Hi Arun Pattanashetti ,

As Geethu Varghese said, at first check mesh quality. The more complex the simulation, the greater the sensitivity to the mesh. If the mesh is ok, perform a simulation without reaction, let the flow stabilize, and then add the reaction.

Geethu Varghese its 3D geometry and mesh quality is good because I have done the meshing by employing ICEM CFD where I have generated structured hexahedron mesh.

Now I am able to get the stabilized solution, the changes I have made is in the methods, i.e I used coupled velocity pressure algorithm and it is giving good result.

Thank you Geethu Varghese.

Ashkan Ghafari Thank you Ashkan, as you said mesh is fine hence I started with non reacting simulation then switched to reacting, and also chosen coupled velocity pressure algorithm now it is working fine.

Hi Arun Pattanashetti, you're welcome.

Good to hear that.