چكيده به لاتين
Bubbly flows appear in many industrial applications and the measurement of the bubble’s size can play a crucial role in the determination of the interfacial region between phases and heat, mass, and momentum transfer between them. In this work, experimental results of the bubble’s diameter are provided in order to achieve a semi-empirical relation for the bubble size in a two-phase gas-liquid flow inside a horizontal pipe as a function of dimensionless numbers of Reynolds and Weber. In the experiments, the air velocities of 0.0224, 0.0408, and 0.0612 m/s and water velocities of 0.657, 0.877, and 1.096 m/s are considered for the under-observation bubbly flow. The length of the pipe is 6 m and its internal diameter is 44 mm. The air will be inserted into the pipe through a 0.5 mm large diameter needle. The instability of laminar type results in the construction of the bubbles. Then, a Nikon camera with the speed of 240 fps is employed to capture the figures that will be analyzed with the aid of an image processing procedure by reducing the background and noise of the pictures. Whenever the bubbles’ diameter is determined by the image processing, these values will be used in combination with regression technique in order to derive a semi-empirical relation for the approximation of the bubbles’ diameter in terms of Weber and Reynolds dimensionless numbers. According to the values attained for the weight coefficients, it is shown that the Saturn mean diameter (SMD) of the bubbles can be manipulated by changing the values of Va and Vw.
