Algorithm for smoke modeling in large, multi-compartmented buildings - Implementation of the hybrid model

  1. Get@NRC: Algorithm for smoke modeling in large, multi-compartmented buildings - Implementation of the hybrid model (Opens in a new window)
AuthorSearch for: ; Search for: ; Search for: ; Search for:
Proceedings titleASHRAE Transactions
Conference2011 ASHRAE Winter Conference, 29 January 2011 through 2 February 2011, Las Vegas, NV
IssuePART 1
Pages777785; # of pages: 9
SubjectAdaptive time step; Building geometry; Energy equation; Energy flow; Far field; Fire dynamics; Fire origin; Fire simulation; Fixed time step; High rise building; Hybrid model; Independent model; Integrated models; Mass flow; Mass flow rate; Network models; Pressure change; Smoke modeling; Smoke movement; Solution procedure; Two-zone model; Zone model; Aerodynamics; Algorithms; Building codes; Energy transfer; Fires; Flow rate; Integration; Mass transfer; Personal computers; Pipe flow; Smoke; Tall buildings; Computer simulation
AbstractRecently, an ASHRAE research project (RP-1328) was completed in which an algorithm for a hybrid model was developed (Kashef and Hadjisophocleous 2010). The hybrid model comprised two integrated models: a zone and a network model. The two-zone model was developed to simulate fire and smoke movement inside the room of fire origin and neighboring rooms. The network model capable ofpredicting both mass and energy flow is used to simulate smoke movement into the rest of the rooms that are far away from the fire-origin room. The two models were combined to produce a hybrid model that allows an accurate simulation of fire dynamics in both the near and far field. The output of the zone model provided a direct input into the network model that included the energy equation. The different steps involved in the development of the hybrid model were included in Kashef and Hadjisophocleous (2011). The application of this model permits a reasonable numerical simulation (time and accuracy) of the fire process, which determines both mass flow and energy transfer over an entire high-rise building using a standard personal computer. This paper presents the implementation of a hybrid model to simulate fires in different building geometries. The hybrid model combined two independent models: a zone model and a network model. The solution procedure consisted of two parts: simulation of two-zone model, which dealt with the room of fire-origin and neighboring rooms, and simulation of the network model, which included rooms far away from the fire. The two-zone and network models were first tested individually; then the performance of the integrated model was investigated in different types of applications. The two-zone model was used to simulate afire in a room of a simple two-story, four-room building. A comparison was made between the two-zone model and CFAST (Jones et al. 2005), a well-known two-zone model for fire simulation. The network model is appropriate for rooms that are far away from the fire origin. A number of tests were performed using examples with different building geometries. A three-story, twelve-room building was used to simulate temperature and pressure changes inside compartment rooms. The mass flow rate comparison was made between the network model and CONTAM (Walton 1997), an existing network model for mass flow rate simulation. A comparison between adaptive time steps and fixed time steps was also included, showing better efficiency made by adaptive time steps. Finally, the models were integrated, where the solutions (temperature and mass flow rate) of the two-zone model become input source for the network model. ©2011 ASHRAE.
Publication date
AffiliationNational Research Council Canada (NRC-CNRC); NRC Institute for Research in Construction (IRC-IRC)
Peer reviewedYes
NPARC number21271193
Export citationExport as RIS
Report a correctionReport a correction
Record identifier38c46098-8a89-45fb-acc6-16977d1d1f30
Record created2014-03-24
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)