Investigation of air bubble motion in counter-current water flow conditions

Download
2003
Bezdegümeli, Uğur
In this thesis study, air bubble motion in counter-current water flow conditions in a vertical pipe is investigated experimentally. For this purpose, a test set-up was designed and constructed. Images of motions of single bubbles, having different diameters in the range of 3.0-4.8 mm, generated by specially designed bubble injectors were recorded by using a monochrome camera, an image capture card and a PC. Recorded video images were processed to obtain the necessary data for the The purpose of the study is to determine variation as a function of the equivalent bubble diameter, water flow velocity and related dimensionless numbers; Reynolds, Re; Eötvös, Eo; and Weber, We, and is to investigate the bubble shapes and bubble travel paths. Bubble behaviour was investigated at six different counter-current water flow velocities (6.5 cm/s, 7.9 cm/s, 10.5 cm/s, 12.9 cm/s, 15.4 cm/s, and 18.2 cm/s) in addition to stagnant water condition which is taken as the reference case. The direction of the bubble motion is upwards and the direction of the water flow is downwards (i.e. counter-current). Distilled water was used in the experiments. The results of this thesis study for the stagnant water condition have shown good consistency with the previous theoretical and experimental studies found in the literature. For the studied range of bubble diameters, it is observed that the bubble average relative velocity for a certain bubble diameter is less under counter-current water flow conditions than that under stagnant water condition and the drag coefficient values for a certain bubble diameter is higher under counter-current water flow conditions than those under stagnant water condition.

Suggestions

Investigation of Turkey's carbon dioxide problem by numerical modeling
Can, Ali; Tokdemir, Turgut; Department of Engineering Sciences (2006)
CO2 emission is very important, because it is responsible for about 60% of the "Greenhouse Effect". The major objectives of this study were to prepare a CO2 emission inventory of Turkey based on districts and provinces by using the fuel consumption data with respect to its sources, to find the CO2 uptake rate of forests in Turkey based on provinces and districts, and to estimate the ground level concentration of CO2 across Turkey using U.S. EPA's ISCLT3 model for the preparation of ground level concentratio...
Determination of critical submergence depth at horizontal intakes under asymmetric flow conditions
Göğüş, Mustafa; Köken, Mete; Haspolat, Emre (2015-07-03)
The purpose of the present study is to investigate the hydraulic conditions of air-entraining vortices under asymmetrical flow conditions and derive a general expression to determine the critical submergence depth required for the formation of these vortices at horizontal intake pipes. A series of experiments were conducted in a model composed of a concrete reservoir and intake pipe which was mounted horizontally to the reservoir. Three pipes of different diameters were tested with adjustable plexiglass sid...
Investigation of the effect of geometrical parameters of pressure swirl atomizer on the hollow cone spray
Tokgöz, Tolga; Ulaş, Abdullah; Department of Mechanical Engineering (2019)
In this study, effects of geometrical parameters of pressure swirl atomizer on the hollow cone spray are investigated experimentally, and physical phenomenon inside the pressure swirl atomizer is investigated numerically. In the experimental studies, hollow cone spray properties are examined macroscopically and microscopically. Macroscopic spray properties are studied by a visual technique called high-speed shadowgraphy. The hollow cone spray images are captured for different geometrical configurations of t...
Investigation of the Linear Stability Problem of Electrified Jets, Inviscid Analysis
Özgen, Serkan; Uzol, Oğuz (2012-09-01)
The instability characteristics of a liquid jet discharging from a nozzle into a stagnant gas are investigated using the linear stability theory. Starting with the equations of motion for incompressible, inviscid, axisymmetric flows in cylindrical coordinates, a dispersion relation is obtained, where the amplification factor of the disturbance is related to its wave number. The parameters of the problem are the laminar velocity profile shape parameter, surface tension, fluid densities, and electrical charge...
Investigation of physical properties of quaternary AgGa0.5In0.5Te2 thin films deposited by thermal evaporation
Karaagac, H.; Parlak, Mehmet (Elsevier BV, 2010-8)
The aim of this study is to understand the structural, optical and photo-electrical properties of the quaternary chalcogenide AgGa 0.5In0.5Te2 thin films deposited onto the glass substrates by thermal evaporation of the single crystalline powder. Energy dispersive X-ray analysis (EDXA) showed remarkable change in atomic percentage of the constituent elements after annealing. The X-ray diffraction (XRD) of the films below the annealing temperature of 300°C indicated the polycrystalline structure with co-exis...
Citation Formats
U. Bezdegümeli, “Investigation of air bubble motion in counter-current water flow conditions,” Ph.D. - Doctoral Program, Middle East Technical University, 2003.