CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Function integral over time (

GAO June 8, 2011 07:15

Function integral over time
Tell me please, is there any possibility to use Ansys CFX time as a parameter in the formulation of transients problems. In the standard features you can not take the time integral. Is there a function integral over time? Or subroutine, which allows to produce a similar action. I'll be very grateful to you for any help in my problem.

ghorrocks June 8, 2011 08:06

What do you want to take the time integral of?

GAO June 9, 2011 03:37

For use as a criterion for stopping the calculation

ghorrocks June 9, 2011 06:51

Sure - note there are already lots of stopping criterion built in so are you sure you need to implement your own?

But what do you need to do the time integral of?

GAO June 9, 2011 08:01

For example, we put on the surface of the paint brush, and we want to calculate what weight we are already done. In fact, we can change the flow of paint in each time, so I want to know how much paint has been applied to the desired point in time. That is the problem confined to the creation of a counter weight of the paint to a certain time.
Or the inverse problem - we have a certain volume of paint, we are doing with various pitch. How much does it for painting?

ghorrocks June 9, 2011 08:13

Arrgh! I did not ask for an example of a time integral, I know very well what time integral is.

What variable do you want to take the time integral of?

GAO June 10, 2011 06:33

Heat flow, for a problem with the heat flow

ghorrocks June 10, 2011 06:44

The time integral of a heat flow is the increase/decrease in heat. So you can do a volume integral of the heat in the domain. No need for a time integral.

GAO June 11, 2011 03:48

The task is next-passing the source of thermal radiation with respect to products with it must be removed a certain number of particles. The rate of passage may vary. The number of these particles we want to calculate. Or calculate the time spent checkpoint in a spot source, which is the same. It is for this and need the time integral.

ghorrocks June 11, 2011 07:28

I am sorry, I do not understand your last post. Can you write it again more clearly?

GAO June 12, 2011 02:03

Calculation of the integral over time is needed for next-motion 2 products relative to each other in time. We need to count how many times one overlaps another. That is needed some counter. The problem of heat.
If you need a figure for clarity, write to send you

ghorrocks June 12, 2011 09:05

I still don't know what you are describing. Please post an image.

GAO June 20, 2011 02:59

In principle, I need to find the time integral of the variable for Ansys not statsianary problem, the picture will not work. Is there a chance?

ghorrocks June 20, 2011 18:41

CFX cannot do time integrals in CEL so it is not easy to do in general.

The reason I am trying to understand what you are doing is often there is another way to implement it, but to suggest something I have to know what you are doing.

Can you tell me what variable you are trying to integrate? And what what is the termination condition you want to apply?

GAO June 23, 2011 03:30 - shoulder movement - impact on the blade flow

ghorrocks June 23, 2011 07:16

I can't seem to view the images on your links. Please put them in the post on the forum, no need for external links.

GAO July 8, 2011 06:26

sorry, no access to the Internet. You are not hard to explain how it should look like?

ghorrocks July 8, 2011 07:04

Sorry, I did not understand that last post.

GAO July 8, 2011 08:09

I mean that in what form you would like to see the pictures?

ghorrocks July 10, 2011 06:44

Yes, please put the images on the forum.

All times are GMT -4. The time now is 18:28.