[Khaza]

Hi Everyone.

I have problem in simulating unsteady flow around a super tall building (300 m ). The main problem is the building is like a tower .See the image in attachment. I am using Ansys fluent 16.0 and I used the Hexmeshing and got the skewness for body mesh as 0.849 (acceptable). I am fine upto this.

The Real problem comes in Solving part. I mean what reynolds number I should use for this building(Please note that it is not like a cylinder problem where u just choose reynolds number for whole geometry) ? How do I choose reynolds number at different parts of my geometry( I have 70m diameter cylinder at bottom and 15 m all the top and then sphere of 25m dia at the very top)?

My domain size in mesh is ( 1750m from inlet to building, 5250m from building to outlet ,2100m from building to top ) . I defined inlet,oulet,and wall functions for topsurface,ground and building in my domain.

Please help me with following questions?

1. What reynolds no. should I use for different parts of my model and how should I apply as a whole?

2.What model should I use ( Laminar or (turbulence since I have super tall building and large domain )?

3.what courant number Should I use?

4.I am defining wind profile by own ,will it create any problems?

5.I can calcaulate timestep once I calculate strouhal number. but again I need Reynolds number to calculate strouhal .

Please help me if I miss any significant step in my modelling process.

Thanks a lot in advance.