IES-VE User Forum

Hi all,

As I know the wind velocities on earth's surface and on river's surface are totally different, usually wind on earth surface is considered to be zero while on river (water) surface is larger than zero. However, in MicroFlo I don't see any implication or functions mentioning about this issue. It should be wrong if MicroFlo considers the wind at the river's surface and earth's surface to have the same value. I am doing External CFD for some master plan projects, but still not confident about the results because I cannot mention the river into the model.

May anybody give me some advices?
How about the opinion from IES people?

Thank a lot.

hrdtm

The air velocity, normal and tangential, at any solid boundary is zero in Microflo. You cannot change this.

There are different terrain types in Microflo to alter the wind boundary profile above ground level at the inflow boundary of the "virtual wind tunnel". I guess these may be of help to you.

I would think that the effect of a moving body of water on the velocity profile above it would be a second order effect and will probably be swapped by error associated with using a turbulence model on a coarser than needed mesh. In other words I wouldn't worry about it.

With all due respect to yourself, and believe me I don't mean to upset you here, and indeed to liamh who's replied already but why the h*ll are you using MicroFlo to look at rivers?

The CFD in IES as far as I'm aware was designed to look at what's happening inside a room. If you are looking at using a product outside it's design parameters you can hardly question the validity of it's results.

I'm sure that there are plenty of specialised and detailed CFD packages that could do this better than a module meant to enhance a building performance analysis package.

I expect the argument to be "but there's a river outside my office"... to which I'd borrow liamh's "wouldn't worry about it".

Awaiting the torrent,
Zap.