[DrFloyd]

hello to everybody,

I started today with fluent and i should study an injection spray in stagnant gas. I found out in a tutorial that it's possible to insert a flow rate profile in injection property selecting the box next "total flow rate", but i have only a "constant" value!!!

please help me to add a profile rate flow instead a constant value.

[macfly]

Hi,

Simplest way is to use a user-defined function (UDF). Go through this tutorial and you will know how to use a UDF: https://www.sharcnet.ca/Software/Flu...lu_tg_vof.html

The UDF you're looking for is DEFINE_PROFILE, read this well documented (with examples) section: https://www.sharcnet.ca/Software/Flu...e_profile.html

There is a learning curve when you start to use UDF but don't panic, it's not that hard if you read carefully the UDF manual, and you will gain a lot of flexibility at using Fluent.

[DrFloyd]

Thank you macfly for the quick reply,

i resolved my problem following the instructions in http://www.arc.vt.edu/ansys_help/flu..._pp_trans.html.

I have another question now..i should want to plot spray penetration of 95% of mass in z axes as funcion of time.. but i don't know how to do...do you have any idea?
thank you again.

[macfly]

Oh I thought you wanted to apply a profile varying in space. Indeed, the method you're using just fine to apply a simple transient profile.

I don't know how you could plot 95% of a variable. But nothing is perfect in CFD, it's a world of approximations, and IMHO 95 % of something is pretty much the same as 100% of something and you could just plot 100% of the penetrated mass and have a very good idea of the 95% result.

[DrFloyd]

Dear macfly,

thank you for your reply, you are right can you help me to plot 100% of the penetrated mass in function of time in z axes? thank you