Gas explosions in facilities may cause significant damage to surrounding buildings and structures due to blast waves. Traditional screening methods (e.g. Multi-Energy Method and TNT Equivalent) have their limitations for realistic geometries. Using the FLACS CFD-tool may provide more valuable predictions
Explosions will, in most cases, generate blast waves. While simple models (TNT-equivalent or Multi Energy Method) are useful for simple explosion geometries, most practical explosions are far from simple and require detailed analyses. For a reliable estimate of the blast from a gas explosion it is necessary to know the explosion strength. The source explosion may not be symmetric, the pressure waves will be reflected or deflected when hitting objects, or even worse, the blast waves may propagate inside buildings or tunnels with a very low rate of decay.
Using FLACS for near and far field blast wave predictions has many advantages. These include more precise estimates of the energy and resulting pressure of the blast wave, as well as the ability to evaluate non-symmetrical effects caused by realistic geometries, gas cloud variations and ignition locations. More specifically, FLACS can be used to evaluate the following details of a given explosion:
- Source strength (pressure) of the explosion
- Dispersion studies to establish the size, shape and concentrations in the gas or vapor cloud
- Directional effects from ignition location and local congestion levels
- Dynamic effects in the near and far field
- Reflection and focusing effects of blast waves
- Time dependent pressure waves
For more information regarding recent blast studies:
- Hansen, O.R., Hinze, P., Engel, D., and Davis S.G., Using CFD for Blast Wave Predictions, Presented at the Mary Kay O'Connor Process Safety Symposium, College Station, USA, Oct. 27-28, 2009.