Improving fire safety design with coupled hybrid modelling
Contents |
[edit] Introduction
A new computer model can provide added insights into fire risks in complex buildings, and help engineers to develop robust fire safety designs. This coupled hybrid modelling has been investigated by Benjamin Ralph as part of a BRE Trust supported PhD studentship at the University of Edinburgh.
Fire engineers commonly use computational fluid dynamics (CFD)-based fire modelling to develop and test the designs of complex buildings. However, as these models are very complicated and this type of simulation takes an impractically long time to run, engineers typically reduce the size of the model to shorten the time needed.
The problem is that a simplified model may not be able to account for the entire building. That means that the ways in which fire and smoke might spread throughout the whole building cannot be fully determined, nor can the effect on the growth and spread of fire and smoke of parts of the building far from the fire. This can put limits on the ability of engineers to develop robust fire safety solutions.
One way of addressing this limitation is the use of ‘coupled hybrid modelling’. This combines the originally used model (which takes a long time to run) and another model (which takes a much shorter time) together. Fire engineers can thereby increase the model size to include more or all of a building, but still carry out a simulation in a reasonable length of time.
[edit] The research
[edit] New model and experimental test rig
A literature review of existing coupled hybrid models identified a lack of collaborative working and the use of proprietary software. Therefore, a coupled hybrid model has been developed, based on the open-source and widely used fire model, Fire Dynamics Simulator (FDS).
A new computer model must be compared with real experiments to confirm that it can represent the real world within reasonable limits. Applicable experimental data were not found during an extensive literature search and discussions with applicable bodies. Therefore, to provide these data, a new experimental rig was specifically designed and built.
[edit] Ventilation issue revealed
Data from the new rig were first used to examine potential holes in the current typical fire safety design model for complex buildings. This analysis showed that there are phenomena related to the two-way coupling of a fire and a shared ventilation system, which may not be captured by commonly used simple engineering methods – or addressed in current design guidance documents.
The new experimental data was then compared with the predictions of the coupled hybrid computer model, and the qualitative and quantitative differences highlighted. The computer model was found to predict fire hazards within the experimental set-up effectively, providing key information needed by future model users to ensure that their analysis is robust.
The original insights into how a total building system and a fire interacts, and the newly developed coupled hybrid model, can be used together by fire engineers. This will help them to deliver design solutions with more deeply understood fire life safety risks for complex buildings that incorporate mechanical ventilation systems.
[edit] About this article
This article was written by the BRE Group and previously appeared on its website in January 2020. It can be accessed HERE.
Other articles by BRE Group on Designing Buildings Wiki can be accessed HERE.
[edit] Related articles on Designing Buildings Wiki
- Approved document B.
- Combustibility.
- Dry riser.
- Emergency services.
- Evacuating vulnerable and dependent people from buildings in an emergency FB 52.
- Fire damper.
- Fire detection and alarm system.
- Fire door.
- Fire protection engineering.
- Fire resistance.
- Fire safety design.
- Fire spread.
- Fire stopping.
- Flame technology.
- Ionisation smoke alarm.
- Joint fire code.
- Optical smoke alarm.
- Protected escape route.
- Protected lobby.
- Managing risks in existing buildings: An overview of UK risk-based legislation for commercial and industrial premises (FB 86).
- The causes of false fire alarms in buildings.
Featured articles and news
Registered building inspectors
Building types and conflicts of interest updates explaineed.
Engineering services still struggle with labour shortages
According to latest quarterly services survey of the sector.
Infrastructure that connect the physical and digital domains.
Harnessing robotics and AI in challenging environments
The key to nuclear decommissioning and fusion engineering.
BSRIA announces Lisa Ashworth as new CEO
Tasked with furthering BSRIA’s impressive growth ambitions.
Public buildings get half a million energy efficiency boost
£557 million to switch to cleaner heating and save on energy.
CIOB launches pre-election manifesto
Outlining potential future policies for the next government.
Grenfell Tower Inquiry announcement
Phase 2 hearings come to a close and the final report due in September.
Progress from Parts L, F and O: A whitepaper, one year on.
A replicated study to understand the opinion of practitioners.
ECA announces new president 2024
Electrical engineer and business leader Stuart Smith.
A distinct type of countryside that should be celebrated.
Should Part O be extended to existing buildings?
EAC brands heatwave adaptation a missed opportunity.
Definition of Statutory in workplace and facilities management
Established by IWFM, BESA, CIBSE and BSRIA.
Tackling the transition from traditional heating systems
59% lack the necessary information and confidence to switch.
The general election and the construction industry
As PM, Rishi Sunak announces July 4 date for an election.
Eco apprenticeships continue help grow green workforce
A year after being recognised at the King's coronation.