'Gas distribution in an office' simulation project by Ali_Arafat


I created a new simulation project called 'Gas distribution in an office':

The project simulates the spread of gas in an office room via Passive Scalar Transport.

More of my public projects can be found here.



Oftentimes, office spaces are enclosed within factories and warehouses that operate with or store gases that are injurious to human health. This makes these enclosed spaces prone to the risk of contamination. It becomes imperative to design rooms and ventilation systems that facilitate the early detection of contaminants. Moreover, sensors should be placed in ideal locations of the room in order to prevent further harm.
Computational Fluid Dynamics (CFD) can provide us with near accurate solutions to depict the flow of gases in an office space. Using the results of these simulations, we can study the gas flow patterns to mitigate the unfavourable outcomes of gas infusion. For the purpose of this project, we use the Passive Scalar Transport, a type of analysis that is widely used in several fluid mechanics applications.

Project Goals

Essentially, Passive Scalar Transport allows one to simulate the transport of a scalar quantity within an incompressible fluid flow. The core assumption of this analysis is that the transported species within the flow does not affect the fluid flow itself (therefore passive).
It is important to note that, scalar transport does not assume any physical dimensions for passive quantities. Therefore, we use this analysis type to study the transport of mass concentration, temperature, etc. in the room.


The CAD model of a standard office space is constructed by our engineers and is imported onto the SimScale platform.


A Hex-dominant automatic (only CFD) mesh is rendered onto the imported geometry. The mesh is set to a moderate fineness and uses 16 computing cores to be generated.
Shown below is the complete mesh of the imported geometry.


Post-meshing, the simulation is set up. The fluid material is assigned as Newtonian, with a Kinematic Viscosity of 0.000013. The density of this gas is assumed to be 1 kg/m3.
The boundary conditions are initialized as follows:

  • Smoke Inlet: On the bottom right corner of the room, we assign the inlet as a velocity inlet with a flow rate of 1m/s.
  • Outlet: The outlet on the top left corner is assigned as a pressure outlet
  • Walls: The rest of the surfaces are assigned as walls with a no-slip condition

Results and Conclusion

This simulation of gas propagation in the office room via Passive Scalar Transport gives us the approximation of mass concentrations and their corresponding temperature at a specified time. This data may be utilized to make design modifications as well as effectively place sensors/smoke-dectors in the room.
The figure below shows the distribution and concentration of the gas at a certain time.