1. Investigation on Local Gas Content For Upward Air–Water Two-Phase Flow And Comparison With Classical Void Fraction Calculation Models.
- Author
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Athar, Muhammad Hassaan, Naqvi, Syed Murawat Abbas, Ali, Hassan Osaf, Rafique, Faisal, Ammar, Muhammad, Waqar, Muhammad, Husnain, Faheem ul, Nadeem, Muhammad Talha, and Waqas, Muhammad
- Subjects
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POROSITY , *TWO-phase flow , *DIGITAL cameras , *MEASUREMENT errors , *OPTICAL flow , *ACCELERATION (Mechanics) - Abstract
Experimental investigation was carried out to calculate local void fraction in a vertical tube having 15 mm and 25 mm inside and outside diameter, respectively, using optical fiber probe technique. This work aimed to estimate the average void fraction of the entire test section from the void fraction at the center of the circular channel. Single- and dual-tip optical fiber probes were used. The high-velocity digital camera method was opted to calibrate optical probes. Deformation, deceleration, and drift effect were the main aspects that brought measurement errors. These effects were studied carefully, and the average error of the local void fraction in the bubbly flow measured by the optical probe is -8.4%. Using Bankoff's variable density model for two-phase flow, a model was established to calculate the average void fraction in the test section. Experiments were performed by varying superficial liquid velocity from 0.1 to 2.0 m s−1 and superficial gas velocity from 0 to 10 m s−1. Results showed that the void fraction increased parabolically for the specific values of superficial water velocity. When superficial air velocity was small, a minor change in its velocity caused the void fraction to increase sharply. The void fraction curve became relatively flat when ug > 2 m s−1. Besides, an assessment was carried out using slip ratio and drift flux correlations to validate the present average void fractional data from the optical probe technique. Excellent agreement was seen between present experimental data points and classical void fraction calculation correlations. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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