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

Research output: ThesisDoctoral Thesis (compilation)

Standard

Fires in Narrow Construction Cavities : Fire Dynamics and Material Fire Performance. / Livkiss, Karlis.

Division of Fire Safety Engineering, Lund University, 2020. 133 p.

Research output: ThesisDoctoral Thesis (compilation)

Harvard

APA

Livkiss, K. (2020). Fires in Narrow Construction Cavities: Fire Dynamics and Material Fire Performance. Division of Fire Safety Engineering, Lund University.

CBE

Livkiss K. 2020. Fires in Narrow Construction Cavities: Fire Dynamics and Material Fire Performance. Division of Fire Safety Engineering, Lund University. 133 p.

MLA

Livkiss, Karlis Fires in Narrow Construction Cavities: Fire Dynamics and Material Fire Performance Division of Fire Safety Engineering, Lund University. 2020.

Vancouver

Livkiss K. Fires in Narrow Construction Cavities: Fire Dynamics and Material Fire Performance. Division of Fire Safety Engineering, Lund University, 2020. 133 p.

Author

Livkiss, Karlis. / Fires in Narrow Construction Cavities : Fire Dynamics and Material Fire Performance. Division of Fire Safety Engineering, Lund University, 2020. 133 p.

RIS

TY - THES

T1 - Fires in Narrow Construction Cavities

T2 - Fire Dynamics and Material Fire Performance

AU - Livkiss, Karlis

N1 - 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. ---

PY - 2020/2/28

Y1 - 2020/2/28

N2 - 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.

AB - 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.

KW - Fire

KW - Ventilated façade

KW - flame height

KW - Stone wool

KW - expanded polystyrene

KW - Fire Dynamics Simulator (FDS)

M3 - Doctoral Thesis (compilation)

SN - 978-91-7895-394-3

PB - Division of Fire Safety Engineering, Lund University

ER -