BATCH PROCCESSING

Roberto Salvador

I have made pressure loss calculations with ansys cfx. I have programmed the basic darcy weisbach equation in order to get such losses. I have validated it comparing the results of the simulation with calculations by hand using the same model. The proccess is as follows:

1.- I have done a model of a straight tube. 2.- I have given as constant value for the problem the friction factor in darcy-weisbach equation. This factor can be obtained by use of Moody's chart, but I want to use the cfx capabilities in order it can calculate it directly.

so I have an equation that gives the same result than Moody's chart. This is the colebrook-white equation. This equation solves the friction factor as a funtion of itself, so if you want to solve it you must solve it by iteration.

This is the first question:

Is there anybody who knows how can i program an iteration in ansys cfx?

colebrook-white equation is as follows:

1/sqrt(lambda)=-2*log(k/(3.7*D)+2.51/(Re*sqrt(lambda)))

The second problem is the following:

I have given initial conditions to the model. I have specified a determined flow rate, but it's constant. So if i want to obtain pressure losses for several flow rates I should run the same simulation several times varying the flow rates in ordel to get such losses.

The question is:

Is there any way to do this in such a way that I can specifiy a flow rate range and ansys can execute the simulation in the flow range specified?

How could I program a bath proccess in ansys cfx?

Thanks in advance