[esp-r] 4-way diffuser CFD modelling

[Andrew Cowie]

Hi all,

I'm trying to model a 4-way diffuser inlet for CFD analysis.  I have tried changing the direction values for the boundary condition in the .dfd file and neither appears to make any difference whatsoever to the flow patterns.  The only other alternative i can think of is to use blockages to model the diffuser directly, however this is a rather fiddly and complex solution to what is only a small part of my model; ideally i would like something simpler.

So my questions are thus:
1. Do the direction values for the air-flow sources in the .dfd file actually do anything?  They cannot be changed via the prj interface and this leads me to believe perhaps they have not been fully implemented yet.  (it is worth mentioning that i'm using a version of ESP-r that is a little old, have these been implemented in a recent revision?)
2. If they DO work, what do they each represent?  I cannot find any documentation on these values.
3. Assuming the values DO work and i know how to use them correctly, will i be able to adequately model a 4-way diffuser using this method?  Or am i barking up the wrong tree entirely?

4. If for any reason this method won't work and i need to model it with blockages, does anyone have any recommendations for doing so as simply as possible?

Thanks in anticipation,
Andy Cowie