Ffowcs Williams and Hawkings solver
 

I want to generate Ffowcs Williams and Hawkings solver code on Matlab/Octave
without Fluent and so on

could anyone guide me on this?

Your best shot would be to actually start from the Fluent reference on this:

S.E. Kim et al., A Versatile Implementation of Acoustic Analogy Based Noise Prediction Method in a General-Purpose CFD Code, AIAA 2003-3202

but a lot depends from your starting point. Do you have a CFD solver at all?