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55
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258
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Citations since 2017
Introduction
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August 2008 - September 2015
Publications
Publications (55)
The current work reports on the performance characterization of a VPSA system developed in-house for ISO-quality green hydrogen generation using commercially available zeolite 13X from two practical multi-specie feed streams generated from near-ambient oxy-steam and air gasification of casuarina wood chips. The breakthrough dynamics in a packed col...
This paper focuses on char gasification in steam towards generating syngas as a part of two-stage gasification technology developed in-house to handle high-ash coal. Controlled experiments in a small-scale packed bed reactor are used to arrive at the dependence of char reactivity using parametric studies like the evolution of temperature, gas compo...
Combustion of char has conventionally been reported to be diffusion controlled. Analytically, the process is reported to follow second order initial diametric (d0) dependence (d0β;β=2) for both single-film (no CO combustion) and two-film models (CO burns in a concentric sphere over the particle). However, experimental investigations indicate deviat...
This paper addresses the char conversion phase as a part of the two-stage gasification, an emerging technology for generating high calorific gas. Control experiments are carried out to establish the char reactivity under relevant environments for the second stage of the reactor. The char is generated by subjecting coal chunks to an oxidative pyroly...
Solid Oxide Fuel Cells (SOFCs) can operate with carbonaceous fuels. However, experiments indicate possible carbon deposition or coking on Ni-based anodes. Thermodynamic equilibrium calculations with NASA computer program CEA (Chemical Equilibrium with Applications) for typical SOFC operating temperatures predict graphitic carbon (C(gr)) formation....
The article presents an experimental investigation on the generation of hydrogen-rich syngas through oxy-steam gasification of corncobs, a key agro-residue available in many countries, to establish biomass gasification coupled with swing adsorption-based multi-component gas separation as a promising route for renewable methanol production. The gasi...
This study presents multi-variable analysis for prediction and optimization of the methanol yield from biomass-based syngas using a thermodynamic model. The biomass-based syngas has a lower H2 content and higher CO2 than the typical syngas obtained from natural gas reforming which is used for the commercial methanol synthesis process. Consequently,...
Skeletal and reduced reaction mechanisms replicate the behavior of full reaction mechanism within the band/regime of optimization criteria and provide specific computational advantages for resource-intense multi-physics domain analysis. The current work reports on the development of skeletal and reduced mechanisms for bio-derived Producer gas and H...
The article addresses the characterization of laminar flame speed of Hythane generated from non thermal plasma reforming of Methane using a dielectric barrier discharge reactor. Hythane with 5%, 10% and 15% Hydrogen fraction is generated by controlling the Methane residence time in the plasma zone. Planar laminar flame speed for the Hythane so gene...
The chapter provides insight into various processes for converting biomass to bio-derived fuels. The thermochemical conversion processes like pyrolysis, hydrothermal cracking, gasification, and similar processes using catalytic or non-catalytic methods developed in various research organizations are summarized. The technology packages developed are...
Non-thermal plasma (NTP) due to their versatile nature have been successfully used in many applications ranging from hydrocarbon destruction to cancer treatment. The NTPs, can deliver high electron temperatures and high densities of radicals at near ambient conditions making it a unique source for applications ranging from treatment of extremely he...
This work reports average electron temperature ( T e) and electron density ( n e) of an atmospheric argon rotating gliding arc ( R G A), operated in glow-type mode, under transitional and turbulent flows. Both T e and n e were calculated near the shortest ( δ) and longest ( Δ) gap between the electrodes, by two different methods using two separate...
The article addresses the implications of adopting (a) non-kinetic theory-based correlations for the estimation of thermodynamic and transport properties and (b) over-simplifying assumptions, as reported in literature, in the numerical simulation of thermo-chemical conversion of char. A one-dimensional char thermo-chemical conversion model with dis...
The full design document for 3Nm3/h (50 LPM) Medical Oxygen Generator is now available under Open Source License from the Indian Institute of Science, Bangalore, India.
The same design document will shortly be hosted on the institute website and all further updates and response to general queries will be updated on the same web page.
The link fo...
A complete design document with supporting CAD drawings for a 3 NM3/h medical Oxygen generation system
Successful application of plasma-activated water (PAW) as an alternate source of nitrogen for agricultural application requires low specific energy consumption. This work reports on a dielectric barrier discharge (DBD) plasma reactor for the generation of PAW having low specific energy (SE) consumption. The SE to produce N in PAW was 3.26 GJ/kg of...
This work presents simple numerical simulation algorithm to analyse the velocity evolution of high density non-magnetized glow discharge (cold) collision-less plasma using Particle-in-Cell (PIC) method. In the place of millions of physical electrons and background ions, fewer particles called super particles are used for simulation to capture the p...
Reactive systems in a thermochemical conversion domain are modelled considering N-specie, 1-energy and 2-mass conservation equations assuming negligible pressure gradient resulting in N+3 non-linear coupled PDE system with dependency on thermodynamic and transport properties. Typically, simplistic temperature-dependent polynomials are chosen for es...
This work investigates the reliability of the function called ‘regionprops’ which is used for measuring the 2D length of the plasma discharge. Work was conducted in a Rotating Gliding Arc ( RGA ) reactor, using air as plasma forming gas. Arc rotational images at three different gas flow rates i.e. 5, 25 and 50 litres per minute LPM were captured us...
Outside Front Cover : This study used plasma acitvated water (PAW) prepared using a dielectric barrier discharge plasma source, with just air as the working gas and without any pressurized flow accessories. Some of the physicochemical parameters of PAW showed linear trend with activation time. Selective killing of a higher proportion of MDA MB‐231...
The development of a quasi-dimensional engine model and its adaptation for CFR configuration for Methane Number assessment of gaseous fuel mixtures is reported. The stochastic model based on eddy entrainment and laminar burn-up concept for turbulent combustion adopts full reaction kinetics with detailed reaction mechanism in the unburned mixture re...
This article investigates the effect of gas flow rate on arc discharge mode and plasma chemistry in a nonmagnetic rotating gliding arc reactor. This article is conducted using oxygen as a plasma forming gas under transient (5 LPM) , turbulent (25 LPM) , and highly turbulent (50 LPM) flow conditions. The voltageendash current ( V-I ) characteristics...
The article reviews the spread of novel coronavirus COVID19 in Tier-I cities in India in the backdrop of the population density of these cities. With the Tier-I cities having population density between 10 to 100 times the national average, these cities account for over 55% of cases nationally and any further spread is most likely to be concentrated...
In this study, cold plasma was used to prepare plasma‐activated water (PAW) from a dielectric barrier discharge plasma source, with ambient air as the plasma‐forming gas. The PAW prepared was characterized for its physicochemical parameters, some of which followed a strong linear correlation with activation time (ta). The effects of PAW addition on...
The document attempts to describe the underlying essence of Taylor's series and presents a methodology for Taylor's expansion in multiple variables. It is an attempt at simplifying the understanding of Taylor's series.
The S3 Medical Oxygen Generator is a device put together at Indian Institute of Science for the generation of Medical Oxygen [O2 93 ± 3 vol%; Balance N2 with CO level: < 5 ppm and CO2 level: < 300 ppm]. The product design is available under Open Source Licensing Terms as an initiative in response to the nCoVID19 crisis. As a part of the design, com...
![Fig. 4. Combustion chamber abnormal P-h traces [Knocking occurrence]](profile/Anand-Shivapuji/publication/334399308/figure/fig4/AS:780827742973952@1563175249053/Combustion-chamber-abnormal-P-h-traces-Knocking-occurrence_Q320.jpg)
This paper presents the evolution of a remote online diagnostic tool to evaluate the plausibility of the operation of any system having a signature sound. As a case in point example, a web enabled Fast Fourier Transformation tool has been developed for real time evaluation of pressure-crank angle trace(s) of a spark ignited engine to detect frequen...
The article addresses two aspects pertaining to homogeneous gas phase systems composed of mixture of gases. The aspects addressed are;
1] Estimation of mixture molecular weight with the knowledge of (a) specie mole fraction in the mixture and (b) specie mass fraction in the mixture
2] Estimation of (a) specie mass fraction knowing the mole fract...
The code is designed for conversion of mole fraction into mass fraction and vice versa. User will have to provide the mole/mass fraction in percentage format for conversion into the mass/mole fraction.
A new rotating gliding arc (RGAD) type reactor is developed without using magnets, with novel approach to electrode configuration suitable for gas cleaning applications. In this work, it is attempted to understand and verify the influence of gas flow dynamics on voltage characteristics and dynamics of the rotating gliding arc. Experiment is conduct...
The sensitivity of empirical correlations and coefficients of thermodynamic quasi and zero dimensional SI engine models to mixture thermo-chemistry and engine thermo-kinematic response variations is addressed. Mixture thermo-chemistry alterations, as in case engine operation with non-regular alternatives, and accompanying in-cylinder fluid flow and...
Hydrogen, either in pure form or as a gaseous fuel mixture specie enhances the fuel conversion efficiency and reduce emissions in an internal combustion engine. This is due to the reduction in combustion duration attributed to higher laminar flame speeds. Hydrogen is also expected to increase the engine convective heat flux, attributed (directly or...
The adoption of automotive natural gas engine for producer gas fuelled stationary power generation application is addressed and for a target power rating, producer gas fuelled engine performance is compared with natural gas (base fuel) performance. Adoption of the engine from natural gas fuelled automotive to producer gas fuelled stationary system...
In light of the limited access to exhaustively instrumented engine infrastructure for investigating the feasibility of use of non-regular fuels, a well validated numerical simulation tool has been developed with full functionality to simulate the performance of a spark ignited engine. Special care has been taken to address some features particular...
The sensitivity of combustion phasing and combustion descriptors to ignition timing, load and mixture quality on fuelling a multi-cylinder natural gas engine with bio-derived H-2 and CO rich syngas is addressed. While the descriptors for conventional fuels are well established and are in use for closed loop engine control, presence of H-2 in syngas...
The current work addresses the use of producer gas, a bio-derived gaseous alternative fuel, in engines designed for natural gas, derived from diesel engine frames. Impact of the use of producer gas on the general engine performance with specific focus on turbo-charging is addressed. The operation of a particular engine frame with diesel, natural ga...
The impact of thermo-physical properties of producer gas on the performance of a natural gas SI engine has been addressed. Energy balance studies reveal the cooling load and exhaust enthalpy to be higher by about 10% as compared to the designed fuels. Analysis of the properties of producer gas indicates the presence of nearly 20% H2 has an influenc...
The paper addresses experiments and modeling studies on the use of producer gas, a bio-derived low energy content fuel in a spark-ignited engine. Producer gas, generated in situ, has thermo-physical properties different from those of fossil fuel(s). Experiments on naturally aspirated and turbo-charged engine operation and subsequent analysis of the...
In-cylinder investigations of producer gas fuelled operation of a spark ignited engine at different loads and mixture quality are reported. The equivalence ratio operating regime is established based on the knock limit on the rich side and cyclic variations on the lean side. The impact of mixture quality on combustion phasing is reported. Combustio...
Analysis and understanding of physical systems require modeling the system as set of simultaneous linear/non linear equations and generating solutions to satisfy the system of equations. Analytical approach towards solving the system of equations remains practical so long as considerable constraints are imposed on the modeled system to bring in sig...
Biomass gasification-a thermo-chemical conversion process, with near zero net carbon emission has a significant potential to displace fossil fuel use especially in various modes of power generation. The current study presents the results from investigations carried out on a six-cylinder natural gas engine rated at 55.0 kW fueled using producer gas...
Projects
Projects (2)
THERMOFLUIDSCITECH has been planned and is being developed as a open access platform and repository catering to aspects related to thermodynamics and fluid dynamics.
Key feature is the evolution of a range of online/web enabled numerical tools corresponding to fluid dynamics and thermodynamics. Some of the tools already hosted and ready to use are thermo-physical property (specific heat, enthalpy, entropy, mach number etc) estimation for species and mixtures, mole to mass to mole fraction conversion, exhaust/mixture Oxygen normalization on dry and wet basis, least square regression analysis tool etc. A range of thermodynamic cycles and practical energy conversion simulation tools are planned for the future. Fuel cells are of particular importance. Along with the online tools, reusable code in Python / R shall also be made available for users to download and use with necessary customization.
Beyond online tools, theoretical and numerical aspects of thermal and fluid systems are also in the scope of the project. Supporting white papers, videos, posters and presentations shall also be uploaded. Data analytics is an interesting section where data relevant to practical systems like laminar flame speed, induction time etc which are computational resource intensive shall be computed and posted online and relevant empirical correlations along with method of estimation shall also be posted.
Aspects related to deep learning and artificial intelligence as relevant to thermal and fluid systems shall also be dealt with.
I would be glad to develop and host any tools desired by individuals and you may contact me specific requests for the same. The website is hosted at
http://www.thermofluidscitech.com
Will keep posted regarding the new tools and content as I host them.
Develop an ECU algorithm based on Machine Learning to render an ECU fuel flexible (within the learning curve)
