IES-VE User Forum

Hi every one
i want to share this information and get some comments from you

the external analysis in the MicroFlo is scientifically known as Wind-induced ventilation:
The wind-induced air flow into a building is affected by the pressure distribution around the building and more specifically at the openings in the building structure. The wind will make an over-pressure at the windward side of the building and an under-pressure at the leeward side and the parallel sides of the building.
so in this case, we are NOT dealing with any thermal analysis at all !!

on the other hand,
Internal analysis is scientifically know as Buoyancy-induced ventilation:
air exchange between two or more zones with different air densities due to difference in temperatures and/or moisture content. so in this case we are based on the thermal condition (boundary condition) and as i know, by adding any types of boundary condition (e.g. general supply diffuser) we can Combined buoyancy and wind ventilation to get more advance analysis.

could you please discuss with me about this matter. is it correct or not ?

many thanks in advance

What you have described is infact the theory on how MacroFlo treats external and internal openings respectively. But the flow through external openings is also influenced by the conditions like temperature difference, moisture content as explained for the internal openings.

The external simulation in MicroFlo converts the building into a completely closed shell and there is no interaction between internal and external environment. In fact all internal data is completely ignored. In internal simulation you can import the boundary conditions derived from the results of dynamic simulation for a particular timestamp and analyze the results.

Hi,

In simple terms, I use the Outside CFD to estimate the pressure coefficients on the building, in order do to calculate the wind component in natural ventilation schemes, and the inside analysis for air distribution inside the spaces.

M N