Influence of Sidewall Effects on Ejected Flame During Facade Calibration Tests: Experimental Analysis and Findings

The inclusion of sidewalls is a typical architectural feature in building façades, which has raised significant concerns about their potential to accelerate flame spread, particularly with the increasing prevalence of high-rise buildings. This paper presents an experimental investigation and analysis of façade flame with a single sidewall. Experiments were conducted by employing a large-scale façade calibration test, following the standard of JIS A 1310 with additional sidewall configurations. The distance between a sidewall and a façade opening was parametrically changed. A propane burner located at the rear center of the combustion chamber provides a quasi-steady heat release rate (HRR) ranging from 600 to 900 kW. It is found that the flame height is more affected by sidewall distances when the HRR is sufficiently larger than the outflow HRR. Combined with flame and façade temperatures, a sidewall distance of 0.2 m is considered crucial for the performance of fire loads in the case of sidewall façades with square openings. The temperature of the flame trajectory is characterized by the neutral plane (NP)-adapted Yokoi model, with improved convergence under varied HRRs and sidewall distances.