Temperature and velocity distributions of a ceiling jet along an inclined ceiling—Part 2: Approximation based on cubic function and coordinate transformation

• Correlations were developed by applying a cubic function and a coordinate transformation.
• Each parameter included was represented as a function of the inclination angle of the ceiling.
• The resultant correlations were verified by making a comparison with the full-scale test data.

Motevalli and Marks and Cooper have represented temperature and velocity distributions at a given radial distance within a ceiling jet that flows under a flat, unconfined ceiling by applying either an exponential function or a trigonometric function, respectively. In representing the distribution of the ceiling jet that flows along an inclined ceiling, the authors developed modified correlations to represent temperature and velocity distribution by applying an exponential function based on data from a series of pool fire tests conducted under a flat, unconfined ceiling with dimensions of 2.5 m (D)×3.0 m (L) and with a change in the angle of inclination of the ceiling reaching 40°. The reproducibility of the apex position of the distribution predicted by the proposed correlations is improved except in the region of attenuation from the apex of the distribution, whose curve has a concavo-convex shape. Therefore, alternative correlations were developed by applying a cubic function and the coordinate transformation taking into account the angle of inclination of the ceiling. The resultant correlations were verified by making a comparison with the full-scale test data, and they showed good correspondence with the data.