Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
NUMERIC SIMULATION OF TURBULENT FLOW DEVELOPMENT IN AN ECCENTRIC CHANNEL WITH CONVECTIVE HEAT TRANSFER
Submission Author:
Diana Caterinne Sandoval Candela , DF , Brazil
Co-Authors:
Diana Caterinne Sandoval Candela, Thiago Gomes, Jhon Goulart
Presenter: Diana Caterinne Sandoval Candela
doi://10.26678/ABCM.ENCIT2018.CIT18-0565
Abstract
Non-isothermal numerical analysis of developing turbulent flow in an eccentric annular channel with outer-diameter, Do = 50.80 mm, Di/Do-ratio of 0.5 and an eccentricity, e = 0.8 was performed. Prescribed heat flux of 100 [W/m^2] was imposed at the inner wall tube, along with insulated boundary condition at outer wall tube. The flow has a Reynolds number of 7300 and a Prandtl number of 0.7. To model the additional diffusion caused by the turbulence, the DES-SST model was employed. Such model solves the flow field switching to LES simulation wherever is possible and k-w SST model in the other regions. The geometry of the problem presented in this work matches with the one used by Choueiri and Tavoularis in their experimental work in the 2014 allowing to validate the dynamics of the flow. A concentric case was also simulated and compared with the analytical equations presented by Gnielinski in his work in 2011. Such work was used as a source of validation of the methodology used for the eccentric case. It was found that the model used were successful in predicting the characteristics of the flow. Quase-peridic flow patterns were found at the gap vicinity and as well as the experimental results, the onset gap instabilities started around x/Dh =30 for all the measurements points. The Nusselt number as was expected, presented a behavior related with the velocity fluctuations, starting to fluctuate around a stable value at the same point as the velocities.
Keywords
Turbulent flow, Eccentric channel, Convective Heat Transfer, Incompressible Flow, DES-SST model, Nusselt number
