Study on the Critical Rotating Speed of a Rotating Magnetic Field Inducing Fire Whirl

By means of the analysis of the moving differential equation for fire whirl, the relationship of a rotating magnetic field between the critical rotating speeds of magnetic field and its intensity is studied in the process of a rotating magnetic field inducing fire whirl, and the rules that the direction change influences on the critical speeds of magnetic flied is also studied. The experimental results show that the upper critical rotating speeds of magnetic field inducing fire whirl increase and the lower critical rotating speeds decrease with the increase of the intensity of magnetic field.And the upper critical va-(lues) of the clockwise-rotating magnetic field are bigger than those of the counter-clockwise-rotating magnetic field,while the lower critical values are reverse.