The effect the design and operating parameters of a pilot vortex burner have on the swirl jet formation and on the jet characteristics is studied. The flow characteristics were studied by mathematically modeling the flow using the ANSYS CFX software package. The performed investigations made it possible to determine the extent to which the swirl parameter n, the ratios of channel diameters m and flow rates of medium in the channels in case of using a two-channel swirl burner design, and the constriction ratio Kcnst influence the flow aerodynamic pattern, including the back flow zone and its characteristics. The region of m and n values at which the aerodynamic conditions necessary for maintaining stable combustion are set up is determined. Matters concerned with performance efficiency of the axial swirling apparatus are considered. A correlation for determining the flow swirling loss factor is presented. It is shown that pressure loss in an annular channel with a swirling device depends not only on the blade setting angle, but also on the ratio of annular channel diameters.