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Prediction of hydraulic efficiency of primary rectangular settling tanks using the non-linear k - ε turbulence model

Firoozabadi, B ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. Publisher: 2010
  3. Abstract:
  4. Circulation is created in some parts of settling tanks. It can increase the mixing level, decrease the effective settling, and create a short circuiting from the inlet to the outlet. All above-mentioned phenomena act in such a way to decrease the tank's hydraulic efficiency, which quantitatively shows how flow within the tank is uniform and quiet. So, the main objective of the tank design process is to avoid forming the circulation zone, which is known as the dead zone. Prediction of the flow field and size of the recirculation zone is the first step in the design of settling tanks. In the present paper, the non-linear k - ε turbulence model is used for predicting the length of the reattachment point in the separated flow of a Karlsruhe tank. Then, the recirculation bubble size, which is out of the capability of standard turbulence models, is determined. Also, the effect of the separation zone size on the tank's hydraulic efficiency is investigated
  5. Keywords:
  6. FTC calculation ; Non-linear k - ε ; Circulation ; Circulation zones ; Dead zones ; FTC calculation ; Hydraulic efficiency ; Non-linear ; Recirculation bubbles ; Recirculation zones ; Separated flows ; Separation zone ; Short circuiting ; Tank design ; Forecasting ; Settling tanks ; Size separation ; Turbulence models ; Hydraulics ; Bubble ; Design ; Efficiency measurement ; Flow field ; Hydraulic property ; Nonlinearity ; Numerical model ; Turbulent flow
  7. Source: Scientia Iranica ; Volume 17, Issue 3 B , 2010 , Pages 167-178 ; 10263098 (ISSN)
  8. URL: http://www.sid.ir/en/VEWSSID/J_pdf/95520103B02.pdf