Dear Deyu Li,
Thanks for your response.
I am following the second paper by B. He (2015). It clearly explains governing equations in the form of T-Ω. These are very much clear to me but I am not able to find much details of equation in the form of ɸ.
How governing equations which are in the form Ω are transformed in the form of ɸ? Could you please comment on this or provide any reference?