Emailing professor for help with (non class related) project I am involved in an extracurricular university-affiliated activity for which I want to do an analysis involving computational fluid dynamics (CFD). There is a professor at my university who has much experience in this area and I would like to reach out to them to ask for suggestions on learning more about using CFD, and hopefully discuss it with them to get feedback on this particular project. I would also like to get involved in this professor’s research, however, this project would be a priority for me, so I would like to express that I would like help on this particular project as well as my interest in research.

I know the basic pointers for reaching out to a professor about research, but how can I express both of my requests at once? Would it be more effective to only request some guidance on the project? Would it come across rude asking for guidance as well as ask to get involved in their research?
I want to do an analysis involving computational fluid dynamics (CFD)...and I would like to reach out to [a professor] to ask for suggestions on learning more about using CFD, and hopefully discuss it with them to get feedback on this particular project. 


As mentioned already, "Visit in office hours or make an appointment." Once you have demonstrated your abilities to the professor, you'll be in a stronger position to:


  get involved in this professor’s research


Although you won't express "both of [your] requests at once," you can present both of your requests in a short time frame. If this isn't an option, then start by discussing CFD and mention that you'd be interested in working with the professor at the end.


  Would it be more effective to only request some guidance on the project?


If you ask for both at the same time, then the professor mightn't know your strengths. Whereas, asking later lets you demonstrate yourself first. 


  Would it come across rude asking for guidance as well as ask to get involved in their research?


It isn't rude. You can ask for guidance and the professor can say "no." You can offer to be involved in their research and they can again say "no."