In the present work, an effervescent atomization spray system has been built with plain-orifice atomizer powered by (water / diesel fuel) and air as atomizing gas in the “inside-out" gas injection configuration. The investigation shows the influence of operation and design parameters on the spray cone angle, liquid mass distribution throughout the spray, flame blow-off and flame length. The gas to liquid mass ratio (GLR) varies from 0.3% to 15%, the liquid mass flow rate varies from 0.5 to 10 g/s and the operating pressure varies from 1 to 6 bar. The results show that spray cone angles lie in the range of 15-22º for all gas to liquid ratios, length to diameter ratios and operating pressures. Liquid mass distribution at different axial distances downstream of the atomizer becomes more uniform at lower (L/D) ratio and higher gas to liquid ratio. Increasing (A/F) ratio leads to decreasing flame length. Moreover, an empirical correlation of cone angle with operating and design parameters has been developed.