@article { ISI:000264309000017, title = {Pressure drop across vortex diodes: experiments and design guidelines}, journal = {Chemical Engineering Science}, volume = {64}, number = {6}, year = {2009}, month = {MAR}, pages = {1285-1292}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Vortex diodes are used as leaky non-return valves in applications where it is desirable to avoid valves with moving parts. Despite their use in practice for several decades, no clear guidelines for design and optimization of vortex diodes are available. Detailed experimental study on flow and pressure drop characteristics of vortex diodes was therefore carried out to evolve such guidelines. The study covered a wide range of vortex diodes. The variation of diodicity (ratio of pressure drop for reverse and forward flow for the same flow rate) with respect to diode geometry, diode size (d(c)), aspect ratio (d(c)/h), nozzle configuration and Reynolds number (Re) was studied. The experimental results were critically analyzed to develop a design methodology. The methodology is shown to be useful for obtaining the diode dimensions that would yield the desired diodicity for the required operating flow rate. (c) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {Aspect ratio, Diodicity, Nozzles, pressure drop, Vortex diode}, issn = {0009-2509}, doi = {10.1016/j.ces.2008.10.060}, author = {Kulkarni, Amol A. and Ranade, Vivek V. and Rajeev, R. and Koganti, S. B.} } @article { ISI:000317469700034, title = {Flow and heat transfer in serpentine channels}, journal = {Aiche Journal}, volume = {59}, number = {5}, year = {2013}, month = {MAY}, pages = {1814-1827}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

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

}, keywords = {computational fluid dynamics, heat transfer, pressure drop, serpentine}, issn = {0001-1541}, doi = {10.1002/aic.13954}, author = {Karale, Chaitanya M. and Bhagwat, Sunil S. and Ranade, Vivek V.} } @article { ISI:000362083400021, title = {Heat transfer and mixing in flow through pinched pipe}, journal = {Canadian Journal of Chemical Engineering}, volume = {93}, number = {10}, year = {2015}, month = {OCT}, pages = {1860-1868}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

There is an increasing trend of using tubular reactors either with passive or active augmentation methods for process intensification. A new passive method with pinching of pipe{\textquoteright} is proposed and investigated for its performance. In the present work, initially, flow in a pinched pipe was studied experimentally and the same was reproduced numerically. The computational model was then used to investigate influences of key geometrical parameters of pinched pipe configuration on pressure drop, heat transfer, and mixing. The simulated results obtained with the pinched pipe were compared with a straight pipe, and with a commonly-used passive augmentation method (twisted tape inserts). The pinched pipe configuration offers better performance and more flexibility in manipulating heat transfer and mixing in intensified devices.

}, keywords = {computational fluid dynamics (CFD), heat transfer, mixing, pinched pipe, pressure drop}, issn = {0008-4034}, doi = {10.1002/cjce.22275}, author = {Hasabnis, Nilesh S. and Totlani, Kartik A. and Ranade, Vivek V.} } @conference {45944, title = {Two phase flow boiling pressure drop in small channels}, booktitle = {IUTAM Symposium on multiphase flows with phase change: challenges and opportunities}, year = {2015}, month = {DEC}, publisher = {IUTAM, Dept Sci Technol India; Ministry Earth Sciences; CSIR; Natl Sci Fdn, USA; Intel Ansys Fujitsu \& TSI India}, organization = {IUTAM, Dept Sci Technol India; Ministry Earth Sciences; CSIR; Natl Sci Fdn, USA; Intel Ansys Fujitsu \& TSI India}, address = {SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Two-phase pressure drop, flow instability and boiling regime identifications are an essential step in the design of a variety of plant in the power and process industries. Despite the wide spread applications, significant experimental data on flow boiling in small channel is not available. In the present work, experimental set-up was designed for studying boiling flows in 19 mm ID tube and identifies flow regimes at various mass and heat flux conditions by varying inlet fluid temperature. The steady-state pressure data was collected and flow regimes identified using pressure drop and pressure fluctuations inside the channel. (C) 2015 The Authors. Published by Elsevier B.V.

}, keywords = {flow boiling, flow instability, pressure drop, regime identification}, doi = {10.1016/j.piutam.2015.04.044}, author = {Sardeshpande, Madhavi V. and Shastri, Parikshit and Ranade, Vivek V.}, editor = {Sahu, KC} }