Scaling of a small scale burner fire whirl

The behavior of a fire whirl generated using a burner is examined using Particle Image Velocimetry. Swirl is generated using two staggered cylinder halves that surround the burner. The unsteadiness of the whirl is characterized, and the ensemble-averaged mean velocity profiles are obtained based on the instantaneous whirl position. The non-dimensional circulation and whirl height, and the Froude number based on the centerline velocity and height above the burner, are shown to follow simple scaling laws. In particular, we show that the non-dimensional whirl height depends only on the non-dimensional circulation.