The computational mesh used in these simulations consisted of over 900,000 cells. The mesh was an unstructured mesh in order to capture the shape of the aircraft nose. The computational mesh also captured the passenger seats and overhead locker configurations.
View of mesh used for fire simulations
Three dimensional layout of VELA cabin fire geometry constructed within SMARTFIRE
.A key finding of this work is that for the fire scenarios considered, flashover did not occur within 480 seconds (after ignition of the external fire). Thus, unlike conventional aircraft, flashover is not the factor driving the available safe egress time (ASET) as this is predicted to occur after 480 seconds – long after passengers would have evacuated the cabin. However, the ASET will be affected by the development of the heat, toxic environment and smoke produced by the fire. The atmospheric conditions within the cabin may have a significant detrimental impact on the evacuation capabilities of the passengers. Furthermore, in the immediate area of the rapture, conditions become quite severe after only 60 seconds thus it is essential that an evacuation strategy be developed to rapidly evacuate passengers in the vicinity of any rupture associated with an external fire.
VELA 1, 1 Class, Status 1, Visibility distance at 1.68m for Scenario 1 at 120sec
VELA 1,1 Class, Predicted temperature contours at the cross aisle connecting the exit 5R at 120 seconds
VELA 1, 1 Class, predicted spread of fire, red dots depict solid surface which is on fire. Click image to view the animation.
VELA 1, 1 Class, predicted temperature evolution at 1.64 m above the floor. Click image to view the animation.