Browsing by Author "Sande, Priya Christina"

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Computational Studies on Gas-Solid Fluidization of Geldart A Particles Using Eulerian-Eulerian Two-Fluid Model
(BITS, Pilani, 2015-05) Sande, Priya Christina
Digital image analysis of gas bypassing and mixing in gas-fluidized bed: effect of particle shape
(Wiley, 2024-10) Mohanta, Hare Krishna; Goyal, Navneet; Sande, Priya Christina; Sharma, Arvind Kumar
The study investigates effect of particle shape on gas bypassing and mixing of gas-fluidized Geldart A particles. A shallow fluidized bed (FB), configured at benchscale, was used with digital image analysis (DIA) for the investigation. The extent of scatter of tracer particles throughout the bed was assessed from DIA images of defluidized powder. A novel method employing Jupyter notebook software, was used to directly determine Mixing Index from digital images. Remarkably, platelet-shaped China clay powder displayed the best mixing characteristics (Mixing Index: 0.79) with no significant bypassing. Angular shaped Quartz displayed moderate mixing (Mixing Index: 0.67), but high bypassing (Bypassing Index: 0.75). Contrary to conventional assumptions, spherical-shaped diatomite exhibited poor mixing (Mixing Index: 0.61) with the highest bypassing (Bypassing Index: 0.82). Platelet particles performed well even with fines removal. Most likely, particle shape significantly influenced the number of available particle contact points, tracer migration, and traceronparticle binding.
Improving Classroom Delivery of Engineering Education Through Design Thinking
(Springer, 2020-07) Sharma, Sangeeta; Sande, Priya Christina
Teaching is an art which requires systematic exploration in manifestations, be it curriculum design, pedagogical strategies and theories, teaching material and practices, and technological interventions. Due to the interface of technology and the mitigating attention span of the students, teachers have realized that the old method of teaching is not relevant anymore. As a result in the different courses offered at the Engineering institute, the teachers are adopting divergent thinking, synectics and design thinking for better understanding of the concepts. Design thinking offers better solutions to the problems and includes analogies and synectics to clarify the concepts. Design thinking aids better student participation and fosters teacher-student relationship. The students are encouraged for team based learning, which make them more attentive. This paper discusses how design thinking has been applied in two popular courses at Birla Institute of Technology and Sciences, BITS Pilani namely General Biology and Computational Fluid Dynamics. The feedback suggests that through analogies and design thinking the profound concepts are made easy to grasp.
Machine learning applied to predict key petroleum crude oil constituents
(Wiley, 2023-10) Mohanta, Hare Krishna; Sande, Priya Christina
Sulfur compounds are the most important inorganic constituents of petroleum and require to be estimated beforehand because of their corrosive nature and other processing anomalies during crude oil processing. Paraffins, naphthene, and aromatics form the bulk of crude oil. Machine learning (ML) predictions of these constituents were made by training the ML model with a diverse industrial data set of 515 oils. The XGBoost model gave an excellent R2 in the range 0.88–0.99 for the bulk compounds. R2 for sulfur was in the modest range of 0.45–0.6, which improved significantly to 0.8 for additional inputs. ML applicability was thereby found to depend on the nature of the constituent. This work furthers ML-based predictions, with the incentive of reducing expensive spectroscopic analytical methods.
Particle image velocimetry investigations on multiphase flow in fluidized beds: A review
(Elsevier, 2023-03) Mohanta, Hare Krishna; Sande, Priya Christina
Fluidized Beds (FBs) are widely employed in the petroleum and coal energy sector because they offer excellent contact, both in terms of high surface area and long times. The last two decades has seen measurement on multiphase flows shift from conventional pressure sensors to direct flow image acquisition and processing. Particle Image Velocimetry or PIV, and PIV coupled with Digital Image Analysis or DIA, are used to directly and instantaneously acquire flow field data to make hidden flow patterns and flow structures discoverable. Research abounds on Gas-Solid FB hydrodynamics using PIV, but Liquid-Solid and Gas-Liquid-Solid systems are only slowly catching up. Similarly, the use of Geldart B and D particles for such studies is very common, whereas A and C type particle hydrodynamics is as yet largely unexplored by using imaging. Turbulence, high temperature, particle clusters, particle agglomeration and dense particle flows pose particular challenges to using PIV in FB. The two-zone FB and micro-FB warrant further attention. Small sized A & C type particles of rod-like, plate-like and angular shape provide huge scope for PIV investigations on FBs in the future. This review provides a concise account of several PIV studies on all types of FBs with focus on the past two decades, and also details the limitations of PIV measurements with future scope of work.
PIV investigation on the effect of gas distributor design for fluidization of Geldart A spherical particles
(Elsevier, 2024-06) Sande, Priya Christina; Sharma, Arvind Kumar; Mohanta, Hare Krishna
This is a hydrodynamics study on gas distribution during fluidization of the industrially relevant Geldart A type particles. The impact of 10 different distributor designs comprising perforated distributors (pitch and orifice arrangement pattern varied) and nozzle distributors (nozzle size varied) were studied experimentally on a bench-scale unit. Particle flow homogeneity in air was determined by a novel Particle Image Velocimetry (PIV) analysis of the freeboard velocity field. Over 50 PIV particle phase vector field images are presented and analysed. Bed expansion, Particle attrition with and without fines, velocity profiles with and without fines and effect of fines on bed expansion were ascertained. Best distributor design for a unit such as Fluid Catalytic Cracking (FCC) regenerator and FCC riser were found to be 0.8 cm and 0.6 cm nozzle plates distributors respectively. Confirmation with previous study revealed a correlation between homogeneous distribution of particulate flow and lower number of turbulence zones.
Reinterpretation of the Geldart A powder classification based on Eulerian–Eulerian CFD simulation
(De Gruyter, 2022-07) Sande, Priya Christina
Geldart classified powders into four categories and assigned each category its own unique characteristic. Geldart A particles, being easily aeratable, show a unique feature of ‘Homogenous expansion’ before bubbling. In this work, an additional feature for the Geldart chart is proposed which adds significant utility for the processing of Geldart A particles. CFD was used to characterize the entire Geldart A region of the Geldart chart based on detailed fluidization behavior. For this, Eulerian–Eulerian Two-fluid model (TFM) simulations were conducted for 25 particle systems across the entire span of the Geldart A region. The simulations (Solid volume fraction (SVF) contours) of bed evolution, taken before the appearance of multiple bubbles, were analyzed in detail. The particle systems were then sub-categorized into Red (5% average bed expansion), Orange (12.5% average bed expansion), and Green (30% average bed expansion) sub-types. The sub-types were plotted on Geldart chart, and for the first time a continuum heat map was generated, from which the ‘level of fluidizability’ of all Geldart A powders can be conveniently gaged. The map can be used for a more informed choice of powder for various industrial applications. Also, the A/B boundary proposed by Verloop was found to be a better fit for our proposed continuum when compared to the original Geldart A/B boundary. The 2D Simulation results performed in this work, found adequate validation against experimental findings in literature. Further, fine mesh 2D simulation results compared well with 3D simulations for dense bed, and were thereby deemed adequate for revealing dense bed behavior before onset of multiple bubbles.
The Role of Time in the Computational Definition of Minimum Bubbling Velocity in Gas-Fluidization
(AICHE, 2014) Sande, Priya Christina
Strengthening the ties: a student exchange programme between Japan and India
(Taylor & Francis, 2021-03) Sharma, Sangeeta; Sande, Priya Christina
In this paper, an effort is made to explore the authors’ involvement as resource persons and facilitators in an exchange programme between Japan and India. The 15-day programme was created to understand the culture and rich heritage of India, particularly Rajasthan, by involving Japanese participants in a Tour based student exchange programme. The programme offered an opportunity for Japanese students to provide an experience of Indian culture through the use of various modules. The paper attempts to explore the impact of learning that took place during the period of the exchange programme, analysed through structured interviews. The findings of this study can facilitate effective creation and development of such exchange programmes in India and elsewhere.
Study of fluidized bed freeboard for effect of Geldart A particles shape using particle image velocimetry (PIV)
(Elsevier, 2024-01) Mohanta, Hare Krishna; Sande, Priya Christina
A study was carried out using Particle Image Velocimetry (PIV) to reveal velocity vector flow fields in the freeboard region of a Geldart A fluidized bed. For the first time the effect of particle shape, was studied for three powder types, namely China clay (platelet-like), Diatomite (spherical) and Quartz (irregular). A bench-scale fluidized bed set-up of perspex glass was used for direct PIV imagining over a substantial inlet gas velocity range. Interestingly the freeboard was not found to be highly turbulent as has been reported in the case of Geldart B particles. Rather a transition regime was observed which was dominated by laminar streamlines and punctuated by short-lived eddies with life span even less than 400 μs. Bed expansion was significantly affected by particle shape. This was explained by an ‘effective cluster size’ hypothesis for the three powder types. The ‘uniformity’ of the velocity field was also quantified for each powder
Synectics model applied in basic theory of computational fluid dynamics
(Sage, 2019-09) Sande, Priya Christina; Sharma, Sangeeta
Computational fluid dynamics is taught in many universities and is a trending elective option among engineering students. Although analyzing computational fluid dynamics simulations is exciting enough, the theory is equation intensive, sometimes very abstract and also difficult to visualize for the novice. A creative thinking based approach termed synectics, which involves analogies, was therefore applied in classroom teaching to increase student comfort with the equations. For this purpose six analogies encompassing basic computational fluid dynamics concepts were developed along with pictorial representations, and are presented in this work. These analogies were integrated into classroom teaching via synectics procedures. Student feedback was positive and reflected higher engagement with the course compared to when the metaphoric activity was not implemented. This work attempts to demonstrate the feasibility and value of applying creative techniques, even when teaching a highly structured and equation oriented course such as computational fluid dynamics.