The pictures show a comparison of piloted (left) and unpiloted (right) transverse jet flames. Note that the flame envelope in the piloted case (left) does not surround the entire jet, allowing for premixing of fuel and crossflow air, just as in the unpiloted lifted flame.

Hasselbrink, E.F. & Mungal, M.G. Transverse jets and jet flames. Part 1. Scaling laws for strong transverse jets, Journal of Fluid Mechanics, 443, 2001, 1 - 25.

Hasselbrink, E.F. & Mungal, M.G. Transverse jets and jet flames. Part 2. Velocity and OH field imaging, Journal of Fluid Mechanics, 443, 2001, 27 - 68.