I am trying to decide a research topic in CFD modeling of combustion. I have gone through a  lot of literature to get an overall idea. I also want to use this forum to get some help. I have following questions

1) what hv we achieved and what is yet to be achieved regarding CFD modeling of combustion (premix, non premix and partial)?

2) are there any particular phenomena that can be predicted only by experiments and not by CFD ?

3) Is there any particular area in CFD modeling of combustion that one should be focusing on, the area that has a potential to predict the results more precisely ?

4) any advice that might help me in deciding the topic