For premixed turbulent combustion in a propane-air mixture at atmospheric pressure and room temperature, having a laminar flame speed of 0.5 m/s, estimate the regime of turbulent combustion (weak-turbulence, distributed-reaction, etc.) for each of the following situations:
(a) The flame is stabilized just downstream from a grid having a mesh spacing of 2 mm in a wind tunnel with an average velocity of 0.6 m/s at the grid.
(b) The flame is held in a burner duct of circular cross-section, 1 m in diameter, by a transverse cylindrical rod 0.1 m in diameter, in a flow with an average velocity of 50 m/s.
(c) The flame is propagating through a cloud 10 m high in the open atmosphere, horizontally, with an ambient wind of 5 m/s.
(d) Combustion occurs in a spherical chamber 0.1 m in diameter having many inlet jets 2 mm in diameter with jet velocities of 100 m/s.