Comparison between FDS prediction and experimental data.

Comparison between FDS prediction and experimental data.</p

The fitted values of coefficients, <i>χ</i>, <i>γ</i> and <i>η</i>.

The fitted values of coefficients, χ, γ and η.</p

Schematic diagram of bifurcation tunnel geometric model.

Schematic diagram of bifurcation tunnel geometric model.</p

Δ<i>T</i>_<i>max</i> obtained by simulations and calculated by models.

ΔTmax obtained by simulations and calculated by models.</p

Fitting coefficients of m and n against bifurcation angles.

Fitting coefficients of m and n against bifurcation angles.</p

The fitting coefficients of <i>γ</i>′ and <i>η</i>′ against dimensionless heat release rate <i>Q</i>*.

The fitting coefficients of γ′ and η′ against dimensionless heat release rate Q*.</p

Temperature contours for various bifurcation angles at HRR of 20 MW (top view).

Temperature contours for various bifurcation angles at HRR of 20 MW (top view).</p

The fitted values of coefficients <i>m</i> and <i>n</i>.

The fitted values of coefficients m and n.</p

Dimensionless temperature rise (Δ<i>T</i>_r/Δ<i>T</i>_<i>op</i>) against dimensionless distance (<i>r</i>/<i>H</i>) along longitudinal direction of branch tunnel with HRR of 5 MW.

Dimensionless temperature rise (ΔTr/ΔTop) against dimensionless distance (r/H) along longitudinal direction of branch tunnel with HRR of 5 MW.</p

Grid size sensitivity analysis.

Grid size sensitivity analysis.</p