Experimental study on longitudinal and transverse temperature distribution of sidewall confined ceiling jet plume

This paper investigates the longitudinal and transverse temperature profiles of a strong plume impinging flow, induced by a turbulent porous gas burner impinging on the sidewall confined ceiling of a long-narrow tunnel-like structure. A series of model scale experiments were conducted for fires against a tunnel sidewall with increasing vertical burner heights (0, 0.17 and 0.35 m), 8 different HRRs (heat release rate) from 15.94 to 106.28 kW were used. Measurements of the vertical temperature profiles against the sidewall and radial horizontal temperature profiles under the ceiling are presented. Results show that for the strong impingement plume, the temperatures at the impingement point can be well correlated by the three-regime of buoyant plume, intermittent flame and continuous flame. The horizontal temperature profiles under the ceiling show obviously asymmetric. It is confirmed that the characteristic length scale of plume radius at ceiling level is sufficiently applicable for predicting the ceiling excess temperatures of strong plume impingement flow, and the correlations of the ceiling excess temperature in both transverse and longitudinal directions are proposed and validated by comparing them with previous research.