02272nas a2200205   4500008004100000022001400041245008000055210006900135260010200204300001400306490000800320520148800328653003301816653001501849653002101864653001801885100003001903700002201933856011101955       2012                        eng d  a0011-389100aComputational fluid dynamics modelling of solid suspension in stirred tanks0 aComputational fluid dynamics modelling of solid suspension in st  aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScJUN  a1539-15510 v1023 a<p>Solid suspension and mixing are crucial in many important processes, including multiphase catalytic reactions, crystallization, precipitation, etc. In recent years, various efforts have been made to numerically simulate solid-liquid flows in stirred vessels using computational fluid dynamics (CFD). In this article, we present a brief account of our group's efforts at developing and using CFD models for simulating solid suspension in stirred tanks. Computational models were developed and evaluated by comparing model predictions with our data as well as published experimental data. A variety of experimental techniques ranging from torque and wall pressure fluctuations to ultrasound velocity profiler were used. Efforts were made to develop appropriate sub-models for capturing influence of the prevailing turbulence and solid volume fraction on effective inter-phase coupling terms. A hysteresis in variation of the height of the cloud of suspended solid with impeller rotational speed was observed. The hysteresis, besides having applications in realizing better suspension at lower effective power consumption, also offers an attractive evaluation test for CFD models. A new way to carry out dynamic settling of solid cloud by sudden impeller stoppage has been developed. The approach, models and results presented here will be useful for extending applications of CFD models for simulating industrial stirred slurry reactors as well as further research in the field.</p>10acomputational fluid dynamics10ahysteresis10asolid suspension10astirred tanks1 aSardeshpande, Madhavi, V.1 aRanade, Vivek, V.  uhttps://library.ncl.res.in/content/computational-fluid-dynamics-modelling-solid-suspension-stirred-tanks-002144nas a2200217   4500008004100000022001400041245005000055210005000105260006700155300001400222490000700236520144400243653003301687653001801720653001801738653001501756100002601771700002301797700002201820856008401842       2013                        eng d  a0001-154100aFlow and heat transfer in serpentine channels0 aFlow and heat transfer in serpentine channels  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcMAY  a1814-18270 v593 a<p>Serpentine channels are often used in microchannel reactors and heat exchangers. These channels offer better mixing, higher heat and mass-transfer coefficients than straight channels. In the present work, flow and heat transfer experiments were carried out with a serpentine channel plate comprising of 10 units (single unit dimensions: 1 x 1.5 mm(2) in cross section, length 46.28 mm, D-h 1.2 mm) in series. Pressure drop and heat-transfer coefficients were experimentally measured. Flow and heat transfer in the experimental set-up were simulated using computational fluid dynamics (CFD) models to understand the mechanisms responsible for performance enhancement. The CFD methodology, thus, developed was applied to understand the effect of various geometrical parameters on heat transfer enhancement. A criterion was defined for evaluation of heat transfer performance (heat transfer per unit pumping power), thus, ensuring due considerations to required pumping power. The effect of geometrical parameters and the corresponding mechanisms contributing for enhancement are discussed briefly. Based on the results, a design map comprising different serpentine channels showing heat transfer enhancement with pumping power was developed for Reynolds number of 200 which will be useful for further work on flow and heat transfer in serpentine channels. (C) 2012 American Institute of Chemical Engineers AIChE J, 59: 1814-1827, 2013</p>10acomputational fluid dynamics10aheat transfer10apressure drop10aserpentine1 aKarale, Chaitanya, M.1 aBhagwat, Sunil, S.1 aRanade, Vivek, V.  uhttps://library.ncl.res.in/content/flow-and-heat-transfer-serpentine-channels-0