VE Application


Undertake internal or external air flow and thermal studies using Computation Fluid Dynamics (CFD).


How it works

MicroFlo enables you to simulate internal conditions in six easy steps:

  • Run ApacheSim to generate boundary conditions
  • In MicroFlo, select the rooms you wish to simulate. Define surface boundary conditions if not using ApacheSim, and make any adjustments (eg. you can place supply and extract grilles)
  • Add additional components (eg. people, computers, radiators)
  • MicroFlo's automatic grid generation tool creates a grid based on the shape of the model, windows, surface objects and component
  • Run and monitor simulation progress
  • Review results

Input Options

Boundary Conditions

  • From ApacheSim
    • Air temperature and moisture content
    • Surface, window and door temperatures
    • All incoming and outgoing air mass flow, temperature and moisture content through each opening
    • Convective room gains split into occupant, equipment, lighting and plant
  • Alternatively, all these properties can be defined easily through the MicroFlo interface

Surface Object Properties

  • Supply grilles
  • Extract grilles
  • Heat flux patches
  • Temperature patches

Include / exclude shading surfaces: adjacent buildings, topographical shades, local shades

CFD Components

  • Radiator
  • Air heat source
  • Solid heat source
  • Any solid component created by user

Automatic Grid Generation

  • Grids can be added to increase the detail in particular regions of the model
  • Non-fixed grids can be removed
  • Grid regions can be edited to change the density between fixed gridlines

CFD Control Settings

  • Turbulence Models: K-e (default) and Constant effective viscosity
  • User defined or MicroFlo calculated (default) surface convective heat transfer coefficients
  • Default initial surface temperatures. This is ignored if the boundary conditions file is available
  • The default size of the cell grid for automatic grid

Analysis Options

  • Simulate both internal and external air flow and thermal problems
  • Pre-set initial conditions for quicker convergence
  • Discretisation options: Upwind (default), Hybrid and Power Law
  • A simulation monitor enables you to run, pause and re-start calculations. Additional options available to:
    • Switch turbulence model
    • Switch between isothermal and thermal simulation
    • Monitor values of variables at points of choice within the domain


  • MicroFlo predicts:
    • internal air flow temperature, direction and velocity
    • external air flow direction and velocity
    • external static pressure
  • Results are accessed via graphical views of 2D slices at any grid line. For example, if you select a particular Z-grid (eg. height) you will get a 2D X and Y-dimension display of the selected variable (eg. temperature or velocity)
  • The range, scale and colour of contours and vectors can be adjusted to improve results interpretation

  • Air flow and heat transfer in and around buildings, taking into account boundary conditions such as the effects of climate, internal energy sources and HVAC systems.
  • Predict occupant comfort temperatures, air temperature and airflow; optimise supply grille placement.
  • Investigate in detail natural and mixed mode ventilation strategies.
  • Most of the effort is taken away and CFD can be incorporated as a vital part of the design process.