To further understand the characteristics of low swirl flow and its effect on the propagation and stability of flame

the characteristics of low swirl flow and combustion in a limited space were studied

through combining experiment method with numerical simulation method. Results show that

changing the diameter of the hole in the plate of center hole can form the swirl injectors with different swirl numbers;in cold state

with increasing of swirl number

gradually formed the “W” shape the velocity vector distribution on spanwise section. there are higher velocity in the annulus zone

lower velocity in central zone and lower velocity outside zone on vertical section. The absorption and heat expansion of gas

vorticity induced and temperature baroclinic effect induce a transition from high swirl flow with recirculation in cold state to low swirl flow without recirculation in combustion state; In a limited space

the low swirl combustion cannot form detached flame

but form a flame similar to the diffusion combustion flame; the temperature distribution boundary and chemical reaction boundary gradually get shorter along spanwise section

and gradually get wider along vertical section.