EXPERIMENTAL EVALUATION OF THE VOID AND PRESSURE WAVES IN A TRANSIENT AIR-WATER HORIZONTAL SLUG FLOW
Lucas Dalla Maria1; Eugênio Spanó Rosa1
1 Universidade Estadual de Campinas, CEP: 13083-860
doi:10.20906/CPS/COB-2015-0710
Resumo
The void and pressure waves in a gas-liquid mixture flowing in the slug regime are experimentally investigated in a horizontal test section made of a transparent plexiglas pipe with 26 mm ID and 26.24 m long operating with air and water. The gas and liquid flow rate transients are made employing a quick aperture valve to the gas change and increasing or decreasing the pump speed thru a frequency inverter. The test grid has four points, the first two points have constant liquid velocity while the gas phase changes in regard the initial steady state. The last two points have constant gas velocity and liquid velocity is changed. The void wave is a jump with constant shape along the test section and well predicted by the drift-flux model. The pressure wave exhibits an overshoot or undershoot only when the gas phase velocity changes. When a transient liquid flow rate is applied the pressure wave exhibits a smooth transition to the final steady state. The pressure wave travels faster than the void wave but its new steady state is achieved only after the void wave has reached the test section outlet.
Palavras-chave: void wave; pressure wave; transient slug flow