Fires in Narrow Construction Cavities: Fire Dynamics and Material Fire Performance

Research output: ThesisDoctoral Thesis (compilation)

Abstract

There have recently been devastating fire incidents related to fire spread over ventilated façades. These incidents indicate gaps in our understanding of the fire behaviour of façades. This thesis takes a bottom-up approach to investigating fire behaviour in materials and elements associated with narrow cavities in modern constructions. Ventilated façade is a construction used as an example in this thesis, in which an air gap is introduced between the thermal insulation and the external cladding.
Experimental and numerical studies were conducted of flame heights and heat fluxes to the surfaces inside cavities. An experimental programme comprising more than 75 individual tests was done with cavity widths between 2 cm and 10 cm, as well as four different heat release rates from the burner. The study showed increasing flame heights and heat flux as the cavity width is reduced. In this experimental study, the flame height increased up to 2.2 times compared to those near one wall. FDS version 6.7.0 software was then used to assess its capability to replicate the experimental results. One of the identified limitations of FDS was the required small mesh cell size. Furthermore, the thermal response of stone wool and expanded polystyrene when exposed to fire conditions was studied. Four types of stone wool with densities of 37 to 154 kg/m3 were investigated experimentally and numerically. Thermogravimetric analysis and micro combustion calorimetry were used to characterize the thermal decomposition of the stone wool’s organic content. A numerical heat conduction model was developed and showed capability of reproducing the temperatures inside stone wool with relatively low density. Suggestions are provided for improving the model’s performance for high density wools.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Engineering and Technology

Keywords

  • Fire, Ventilated façade, flame height, Stone wool, expanded polystyrene, Fire Dynamics Simulator (FDS)
Original languageEnglish
QualificationDoctor
Supervisors/Assistant supervisor
  • Patrick van Hees, Supervisor
  • Bjarne Paulsen Husted, Assistant supervisor
  • Lauridsen, Dan, Assistant supervisor, External person
Thesis sponsors
  • European Commission
  • Danish Institute of Fire and Security Technology
Award date2020 Feb 28
Publisher
  • Division of Fire Safety Engineering, Lund University
Print ISBNs978-91-7895-394-3
Electronic ISBNs978-91-7895-395-0
Publication statusPublished - 2020 Feb 28
Publication categoryResearch

Bibliographic note

Defence details Date: 2020-02-28 Time: 09:15 Place: Lecture hall V:B, building V, John Ericssons väg 1, Faculty of Engineering LTH, Lund University, Lund. External reviewer(s) Name: Roguame, Thomas Title: Prof. Affiliation: Pprime Institute University of Poitiers, France. ---

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Related research output

Karlis Livkiss, Husted, B. P., Beji, T. & Patrick van Hees, 2019, In : Fire Safety Journal. 108, 102834.

Research output: Contribution to journalArticle

Karlis Livkiss, Svensson, S., Husted, B. & Patrick van Hees, 2018, In : Fire Technology. 54, 3, p. 689-713

Research output: Contribution to journalArticle

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