# How to get summation of one variable at x directio

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 October 19, 2003, 21:18 How to get summation of one variable at x directio #1 zhou1 Guest   Posts: n/a I simulate a 2-D fluid flow in a rectangle channel. I need to get the summation of one transport variable along x-direction at every y coordinate. How can I get it using UDF in FLUENT or other methods? Thanks.

 October 20, 2003, 12:01 Re: How to get summation of one variable at x dire #2 ap Guest   Posts: n/a I'm not sure if I understood your problem. If you just need to integrate a variable along x-direction at a fixed y during post-processing, you have to create a line along x-direction, at the y value you want. Then integrate the flow variable un that line, using the Surface Integral tool. Hi ap

 October 20, 2003, 14:29 Re: How to get summation of one variable at x dire #3 zhou1 Guest   Posts: n/a Yes, i want to integrate one variable along x-direction. I know your method works. However, i need to integrate it at every fixed y value and use this intergration in new iteration. For example, y=0 to 1 and step size is 0.0001. If i use line-creation, it will cost too much lines. So, is there any others method to get this intergration? Thanks.

 October 21, 2003, 10:17 Re: How to get summation of one variable at x dire #4 ap Guest   Posts: n/a You should be able to do that using geometry macros to retrieve positions and then integrate your variable using an algorithm of your choice, but I've neved done it. This, however requires your grid to be as fine in the y direction as the step you want to use for your y variable. Maybe there are better and easier methods. Hi ap