Turbulent Energy Dissipation Rate and Turbulence Scales in the Blade Region of a Self-Aspirating Disk Impeller
سال انتشار: 1398
نوع سند: مقاله ژورنالی
زبان: انگلیسی
مشاهده: 157
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شناسه ملی سند علمی:
JR_JAFM-12-3_007
تاریخ نمایه سازی: 15 دی 1400
چکیده مقاله:
Instantaneous radial and axial velocitieques of water in the tank with a self-aspirating disk impeller operating without gas dispersion were measured by the PIV method. A comparison of mean square velocity pulsations confirmed previous observations that the area in which turbulence is non-isotropic is small and extends about ۳ mm above and under the impeller and radially ۱۲,۵ mm from the impeller blade tip. Based on velocity measurements, the distributions of energy dissipation rates were determined using the dimensional equation = C•u’۳/D and Smagorinsky model. Adoption of the results of the dimensional equation as a reference value allowed us to determine the Smagorinsky constant value. This value appeared to be smaller than the values given in the literature. It has been shown that eddies in a small space near the impeller had sufficient energy to break up gas bubbles flowing out of the impeller. Based on the obtained energy dissipation rate distributions, appropriate turbulence scales were determined.
کلیدواژه ها:
نویسندگان
J. Stelmach
Lodz University of Technology, Faculty of Process and Environmental Engineering Wolczanska ۲۱۳, ۹۰
R. Musoski
Lodz University of Technology, Faculty of Process and Environmental Engineering Wolczanska ۲۱۳, ۹۰-۹۲۴ Lodz, Poland
C. Kuncewicz
Lodz University of Technology, Faculty of Process and Environmental Engineering Wolczanska ۲۱۳, ۹۰-۹۲۴ Lodz, Poland
M. Glogowski
Lodz University of Technology, Faculty of Process and Environmental Engineering Wolczanska ۲۱۳, ۹۰-۹۲۴ Lodz, Poland