This chapter contains some basic information about the C programming language that may be helpful when writing UDFs in Ansys Fluent. It is not intended to be used as a primer on C and assumes that you are an experienced programmer in C. There are many topics and details that are not covered in this chapter including, for example, while and do-while control statements, unions, recursion, structures, and reading and writing files.

If you are unfamiliar with C, consult a C language reference guide (such as [6] or [9]) before you begin the process of writing UDFs for your Ansys Fluent model. Note that Ansys Fluent supports version C99 and earlier.