03863ntm a2200301 i 4500003000800000005001700008006001900025007000300044008004100047020003300088040002500121100004000146245013800186264003600324264001200360300007000372336002100442337002500463338002300488347002400511500006400535502007000599504004000669520270200709610007903411650004503490650002603535MY-KuUP20251125110925.0t||||fr|||| 000 0 ta240917t20242024my a|||fr|||| 000 0 eng d  aTHE0009964 (Local)qHardback  aUMPSAbengcUMPerda0 aNiellambare A/p Nadumaran,eauthor.10aThe effect of geometry and flow conditions on the microbubble formation in venturi microbubble generator /cNiellambare A/p Nadumaran 1aKuantan, Pahang :bUMPSA,c2024 4c© 2024  axiv, 96 pages :billustrations (some color) ;c30 cm. +e1 CD-ROM  2rdacontentatext  2rdamediaaunmediated  2rdacarrieravolume  2rdaatext filebPDF  aFaculty of Mechanical and Automotive Engineering Technology  aThesis (Master of Science) -- Universiti Malaysia Pahang – 2024  aIncludes bibliographical references3 aThe Venturi microbubble generator (VMBG) is a device that creates microbubbles (MBs)  using a simple structure and mechanism. Its effectiveness is determined by the size  distribution of the generated bubbles (BSD) to meet specific application requirements.  Two key parameters affecting VMBG performance are its geometric configuration and  flow conditions. Most research had focused on their impact on BSD, but it is also  important to consider their relationship to the mechanism of bubble formation and bubble formation characteristics. Despite many recent experimental visualizations, the  relationship between key parameters and bubble formation in VMBG has been underdiscussed due to the challenges in studying MB formation mechanisms through  experimental visualization. Thus, this study extensively investigated the effect of the two  key parameters, geometry configuration and flow conditions of VMBG on the bubble’s  formation characteristics. An ideal VMBG and nine additional VMBGs were designed  by varying the angle of divergent section, the diameter and length of throat. Particle  Image Velocimetry (PIV) setup is used to observe bubble formation and flow velocity  distribution between the throat and divergent section of the VMBG. The flow condition  varied with three flow rates (50LPM, 60LPM, and 70LPM) in this study. To further  investigate the bubble breakup phenomenon, computational simulation (ANSYSFLUENT) was used to determine the detailed flow properties in the VMBG. As a result,  the bubble formation characteristics strongly dependent on the flow condition such as  velocity, turbulent intensity and vorticity. As velocity increases in the throat section, there  is a corresponding rise in turbulent intensity and vorticity in the divergent section,  intensifying the bubble formation. Regarding geometric variations, a larger divergent  angle (60º) leads to the formation of smaller and denser bubbles, with a velocity of  5.64m/s and turbulence of 0.411 while a smaller throat diameter (10mm) enhances bubble  formation in the VMBG with a velocity of 5.08m/s and turbulence of 0.411. Additionally,  a longer throat (30mm) promotes the creation of larger, elongated bubbles, with  maximum turbulence of 0.262 while a shorter throat has maximum turbulence of 0.285 resulting in smaller, fragmented bubbles. To sum up, crucial parameters like geometrical  configuration and flow conditions play a pivotal role in altering the flow characteristics  and thus affecting the bubble formation, eventually leading to controlling the generated  bubble size. This research could guide in designing VMBG according to the desired  bubble size and application requirements.20aFaculty of Mechanical and Automotive Engineering TechnologyxDissertations 0aUniversities and collegesxDissertations 0aThesesxDissertations