Assist gas behaviours in the cutting groove of different thickness

The behaviour of assist gas flow in the cutting groove of different material thickness was investigated. Based upon the real shapes of cutting grooves, simulation model was established using the CAD drawings. The cross-section in the direction perpendicular to the cut have a throat at both side walls in the groove owing to the effect of focal position. The simulation results shows that these throats can make accepted the assumption of the pseudo equation of continuity of gas flow under the boundary condition of walls in the groove. An assist gas behaviour of jetting gas velocity and gas pressure in the cutting groove was estimated by simulation. And for ascertain the significance of the principle of conservation of mass in the condition, the mass flow rate was calculated using the theory of quasi-gas dynamics and actual measurement for an assist gas flow in the cutting groove.