Study of gas-dynamic processes of interaction of chordal gas jets with a vortex air flow

RELEVANCE . The nozzle block is the important element of block burners, determining the efficiency and reliability of the burners. Most commercially available nozzle blocks incorporate a disk with swirl vanes to generate flow turbulence; however, such disks create significant gas-dynamic drag. THE PURPOSE . To study the influence of combustible gas feed angles (angle to the axis β and chord angle α) on gas distribution across the cylinder cross-sections, the degree of flow swirl, and the degree of vacuum using forced air supply by an axial fan without the use of swirl disks. METHODS . The study was performed numerically for isothermal jets and flow in the ANSYS Fluent software package using the SST k-ω turbulence model. RESULTS . The minimum variation coefficient for all considered configurations was found to be achieved at a swirl number of about S=0.4-0.5. Vacuum pressure depends on the combination of angles β and α, the maximum was achieved at β = 90°/α = 15°. The swirl rate depends on both the swirl number S and the combination of angles β and α, with each angle β having its own range of S variation to maintain the maximum swirl rate. CONCLUSION . A configuration (β = 90°/α = 26°) was found to achieve a compromise between a high swirl (S=0.58-0.48), an extended low-pressure zone (with a peak point of -433 Pa) and uniform gas distribution in the sections of the nozzle block: variation coefficient varied within the range from 41% (1 caliber from the inlet section) to 13% (outlet section). The results of the work are of practical value for the design of burner devices and further calculations using the combustion model.