Browsing by Author "Kumar, S.S."

Now showing 1 - 8 of 8

EFFECT OF NOZZLE CONFIGURATION ON PERFORMANCE OF A SPRAY DRYER
(University of Chemical Technology and Metallurgy, 2024) Ali, A.A.; Kumar, S.S.
In this work, hydrodynamics and drying characteristics of spray dryer is numerically investigated using computational fluid dynamics (CFD) using Euler-Lagrangian (EL) approach. The gas phase is modelled as the continuous phase and solid particle as the dispersed phase. The turbulence in the gas phase is predicted using RNG version of k-ε model. As airflow pattern influences the time spent by particle in drying chamber, the spatial variation of air velocity and its circulation rate is quantified. Accordingly, optimum conditions for drying the feed slurry are determined. Further, five different outlet pipe locations are chosen and the optimum location is identified which supports the highest evaporation rate. To improve the product quality, conventional nozzle is modified and particle impact positions are analyzed. The particles impact positions on the dryer’s surface are found to be minimum for the proposed nozzle configuration and it improves the final product quality. © (2024), (University of Chemical Technology and Metallurgy). All Rights Reserved.
Local heat transfer distribution on a flat plate impinged by a swirling jet generated by a twisted tape
(2017) Kumar, S.S.; Hindasageri, V.; Prabhu, S.V.
An experimental investigation is conducted to study the local heat transfer distribution on a flat surface normally impinged by a swirling air jet. Twisted tapes of twist ratios equal to 2, 3.2, 4.5 and 7.5 (corresponding swirl numbers S = 0.79, 0.49, 0.35, 0.21) are inserted in a circular tube to generate swirling effect. Experiments are carried out for Reynolds number varying from 500 to 3000 for jet to plate spacing varying from 1 to 4. The local heat transfer characteristics are estimated using thermal images obtained by thermal infrared imaging technique. The jet flow profile on the target plate is evaluated by the flow visualisation carried out using lamp black technique. The heat transfer rate is found to initially increase with the increase in twist ratio (or decrease in swirl number) from 2 to 4.5 and thereafter it reduces with the increase in the twist ratio from 4.5 to 7.5. The heat transfer rate is maximum for a twist ratio of 4.5 and minimum for a twist ratio of 7.5. The jet to plate spacing also shows strong influence on the heat transfer rate. With the increase in jet to plate spacing, the heat transfer rate decreases. The maximum heat transfer rate is obtained at z/d = 1 for the different twist ratios and Reynolds number. 2016 Elsevier Masson SAS
Local heat transfer distribution on a flat plate impinged by a swirling jet generated by a twisted tape
(Elsevier Masson SAS 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2017) Kumar, S.S.; Hindasageri, V.; Prabhu, S.V.
An experimental investigation is conducted to study the local heat transfer distribution on a flat surface normally impinged by a swirling air jet. Twisted tapes of twist ratios equal to 2, 3.2, 4.5 and 7.5 (corresponding swirl numbers S = 0.79, 0.49, 0.35, 0.21) are inserted in a circular tube to generate swirling effect. Experiments are carried out for Reynolds number varying from 500 to 3000 for jet to plate spacing varying from 1 to 4. The local heat transfer characteristics are estimated using thermal images obtained by thermal infrared imaging technique. The jet flow profile on the target plate is evaluated by the flow visualisation carried out using lamp black technique. The heat transfer rate is found to initially increase with the increase in twist ratio (or decrease in swirl number) from 2 to 4.5 and thereafter it reduces with the increase in the twist ratio from 4.5 to 7.5. The heat transfer rate is maximum for a twist ratio of 4.5 and minimum for a twist ratio of 7.5. The jet to plate spacing also shows strong influence on the heat transfer rate. With the increase in jet to plate spacing, the heat transfer rate decreases. The maximum heat transfer rate is obtained at z/d = 1 for the different twist ratios and Reynolds number. © 2016 Elsevier Masson SAS
Multi-objective optimization of friction welding parameters in AISI 304L austenitic stainless steel and copper joints
(2016) Shanjeevi, C.; Kumar, S.S.; Sathiya, P.
Friction welding is a solid-state joining technique, and joining of dissimilar materials has been witnessing tremendous development in various applications. In this study, friction welding is carried out in dissimilar materials, austenitic stainless steel and copper, which find application in power generators. The parameters such as friction pressure, upset pressure, rotational speed and burn-off length are considered to determine its influence on tensile strength, metal loss and weld time. Taguchi's L27 orthogonal array is used for experimental design to maximize the tensile strength as well as minimize the metal loss and weld time. Optimal parameters are determined through multiple performance characteristics, and it is found that friction pressure of 22 MPa, upset pressure of 108 MPa, rotational speed of 500 r/min and burn-off length of 1mm yield good mechanical and metallurgical properties. IMechE 2014.
Multi-objective optimization of friction welding parameters in AISI 304L austenitic stainless steel and copper joints
(SAGE Publications Ltd info@sagepub.co.uk, 2016) Shanjeevi, C.; Kumar, S.S.; Paulraj, P.
Friction welding is a solid-state joining technique, and joining of dissimilar materials has been witnessing tremendous development in various applications. In this study, friction welding is carried out in dissimilar materials, austenitic stainless steel and copper, which find application in power generators. The parameters such as friction pressure, upset pressure, rotational speed and burn-off length are considered to determine its influence on tensile strength, metal loss and weld time. Taguchi's L27 orthogonal array is used for experimental design to maximize the tensile strength as well as minimize the metal loss and weld time. Optimal parameters are determined through multiple performance characteristics, and it is found that friction pressure of 22 MPa, upset pressure of 108 MPa, rotational speed of 500 r/min and burn-off length of 1mm yield good mechanical and metallurgical properties. © IMechE 2014.
Overview of Shared Task on Multitask Meme Classification - Unraveling Misogynistic and Trolls in Online Memes
(Association for Computational Linguistics (ACL), 2024) Chakravarthi, B.; Rajiakodi, S.; Ponnusamy, R.; Pannerselvam, K.; Anand Kumar, M.A.; Rajalakshmi, R.; LekshmiAmmal, H.R.; Kizhakkeparambil, A.; Kumar, S.S.; Sivagnanam, B.; Rajkumar, C.
This paper offers a detailed overview of the first shared task on "Multitask Meme Classification - Unraveling Misogynistic and Trolls in Online Memes," organized as part of the LT-EDI@EACL 2024 conference. The task was set to classify misogynistic content and troll memes within online platforms, focusing specifically on memes in Tamil and Malayalam languages. A total of 52 teams registered for the competition, with four submitting systems for the Tamil meme classification task and three for the Malayalam task. The outcomes of this shared task are significant, providing insights into the current state of misogynistic content in digital memes and highlighting the effectiveness of various computational approaches in identifying such detrimental content. The top-performing model got a macro F1 score of 0.73 in Tamil and 0.87 in Malayalam. Â© 2024 Association for Computational Linguistics.
Simulation of coastal aquifer using mSim toolbox and COMSOL multiphysics
(2020) Kumar, S.S.; Deb, Barma, S.; Amai, M.
Fluctuations in groundwater levels along the coast have a significant impact on the extent of saltwater intrusion into freshwater aquifers. This study aims to simulate the groundwater flow and solute transport in the region by using the mSim toolbox in the MATLAB and COMSOL Multiphysics. The investigation is focussed on a micro-basin of Pavanje river located along the west coast of India. The model results are calibrated and validated against the field observations. The results show that the variation of the water table over the year is significant and range from about 3 14 m. There exists a reasonable correlation between the simulated and observed values of groundwater level and salinity. The wells that are most vulnerable to seawater intrusion in the region are identified. The COMSOL model estimated a salinity range of 0 20 mol/m3. Additionally, the model is used to understand the response of coastal aquifer to various stress scenarios. The study reveals that reduced recharge rate with increased pumping has a serious impact on aquifer system. 2020, Indian Academy of Sciences.
Simulation of coastal aquifer using mSim toolbox and COMSOL multiphysics
(Springer, 2020) Kumar, S.S.; Deb Barma, S.; Mahesha, M.
Fluctuations in groundwater levels along the coast have a significant impact on the extent of saltwater intrusion into freshwater aquifers. This study aims to simulate the groundwater flow and solute transport in the region by using the mSim toolbox in the MATLAB and COMSOL Multiphysics. The investigation is focussed on a micro-basin of Pavanje river located along the west coast of India. The model results are calibrated and validated against the field observations. The results show that the variation of the water table over the year is significant and range from about 3–14 m. There exists a reasonable correlation between the simulated and observed values of groundwater level and salinity. The wells that are most vulnerable to seawater intrusion in the region are identified. The COMSOL model estimated a salinity range of 0–20 mol/m3. Additionally, the model is used to understand the response of coastal aquifer to various stress scenarios. The study reveals that reduced recharge rate with increased pumping has a serious impact on aquifer system. © 2020, Indian Academy of Sciences.