INVESTIGASI FRAKSI HAMPA ALIRAN DUA FASE UDARA AIR DAN GLISERIN (0-30%) PADA PIPA KAPILER DENGAN KEMIRINGAN 15˚ TERHADAP POSISI HORISONTAL

Two-phase flow is a typical example of multiphase flow. Two-phase flow can be found in various applications in the industrial world such as boilers, cores and steam generators in nuclear reactors, petroleum transportation, electronic refrigeration and many other types of chemical reactors. Two-phase flow that exists in nature such as rain, fog, and various other natural phenomena. The purpose of this study was to determine the length of the fluid pattern, the velocity of the flow pattern, and to determine the frequency of the flow pattern, to predict the change of the flow pattern transition changes in a twophase flow with a slope of 15˚ in a horizontal capillary tube. The fluid used is a mixture of air-water and glycerin with a concentration of 0, 10, 20 and 30%. To determine the empty fraction, one of the tests carried out is the digital image processing method using the MATLAB R2014a application program. High-speed camera is used for shooting video at a speed of 1200 fps and a resolution of 640 x 480 pixels. The adiabatic research conditions at gas superficial velocity (JG) interval 0.025 66.3 m / s, and liquid superficial velocity (JG) interval 0.033 - 4.935 m / s experiment was carried out. The results showed that the higher the superficial velocity of the gas, the higher the value of the void fraction obtained. The viscosity of the fluid greatly affects the flow pattern of the bubbly and plug. This is because the higher the viscosity of the fluid, the velocity of the bubbly and plug flow patterns will decrease. The higher the value of the homogeneous void fraction (β) will affect the length of the bubbly and plug flow pattern, so the length of the pattern will increase. The frequency of appearance of the bubbly and plug flow patterns was found to be quite high, this resulted in an increase in the value of the vacuum fraction produced.