CFD wind modelling using Lawson Criteria

2 posts / 0 new
Last post

I need to carry out a Pedestrian wind comfort (Lawson) Assessment using
ANSYS CFX, I'm reading 'Wind Effects on Buildings' and the Franke et al
paper etc. but it's still not entirely clear to me. If you have any
guidance that would be great, particularly:

* How many wind directions are required? Lawson and the BRE
DG520 suggest 12 but I have heard of 8 directions being used. There's a
big difference in processor/ post-processing time between the two.

* How are the results from the CFD usually post-processed to
produce the acceptability criteria throughout the domain? Is it a case
of writing some kind of script for the postprocessor using weighting
functions based on the local wind data? Are there any examples or
guidance on this?

* Any guidance on suitable turbulence models for CFX?

* Finally what wind speed is used for the actual modelling, I
assume the 10 year average speed then post processing takes account of
variation in local wind speed, peak gust etc?

Thanks,

Dr Claire Das Bhaumik CEng MCIBSE

Claire Das Bhaumik2's picture
Joined: 2011-10-02
Reputation: 0