Simulation of turbulent non-isothermal polydisperse bubbly flow behind a sudden tube expansion
M.A. Pakhomov and V.I. Terekhov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
E-mails: pakhomov@ngs.ru; terekhov@itp.nsc.ru
Keywords: bubble separated flow, turbulence, heat transfer enhancement, simulation
Pages: 693–699
Abstract
The results of numerical simulation of the structure of non-isothermal polydisperse bubbly turbulent flow and heat transfer behind a sudden tube expansion are presented. The study was carried out at a change in the initial dia-meter of the air bubbles within dm1 = 1–5 mm and their volumetric void fraction β = 0–10 %. Small bubbles are available in almost the entire cross section of the tube, while the large bubbles pass mainly through the flow core. An increase in the size of dispersed phase causes the growth of turbulence in the liquid phase due to flow turbulization, when there is a separated flow of liquid past the large bubbles. Adding the air bubbles causes a significant reduction in the length of the separation zone and heat transfer enhancement, and these effects increase with increasing bubble size and their gas volumetric flow rate ratio.
DOI: 10.1134/S0869864316050073
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