Search

Your search keyword '"Vujanović, Milan"' showing total 439 results
Start Over Author "Vujanović, Milan"
439 results on '"Vujanović, Milan"'

27. Numerical analysis of sulfur dioxide absorption in water droplets

Author

Bešenić Tibor, Vujanović Milan, Baleta Jakov, Pachler Klaus, Samec Niko, and Hriberšek Matjaž

Subjects
gas absorption, mass transfer coefficient, flue gas desulfurization, penetration theory, film theory, Physics, QC1-999
Abstract

Mass transfer between the phases is a cornerstone of many technological processes and presents a topic whose understanding and modelling is of high importance. For instance, absorption of gases in liquid droplets is an underlying phenomenon for the desulfurization of flue gases in wet scrubbers. Wet scrubbing is an efficient cleaning method where the liquid is sprayed in a stream of rising gases, removing pollutants due to the concentration difference between the gas phase and droplets. A model for absorption in water droplets has been developed to describe the complex physical and chemical interactions during the exposure to flue gases. The main factors affecting the absorption are the mass transfer of pollutants through the gas–droplet interface and the aqueous phase chemistry in a droplet. The mass transfer coefficient, which has been modeled with several approaches, is the most significant parameter regulating the absorption dynamic into the droplet, while the in-droplet chemistry controls the maximum quantity of dissolved pollutants. Dissociation of sulfur dioxide and the chemical reactions in seawater have been described by the equilibrium reactions. Afterward, the influence of the mass transfer coefficient has been investigated, and the model has been validated against the literature data on a single droplet scale. Obtained results are comparable with the experimental measurements and indicate the applicability of the model for the design and development of industrial scrubbers.

Published
2020
Full Text
View/download PDF

48. Numerical assessment of polyoxymethylene dimethyl ether (OME3) injection timing in compression ignition engine.

Author

Marković, Marijan, Jurić, Filip, Šošić, Dominik Pečaver, Schmalhorst, Carsten, Hoang, Anh Tuan, and Vujanović, Milan

Subjects
DIESEL motors, METHYL formate, METHYL ether, POLYOXYMETHYLENE, GAS phase reactions, DIESEL fuels, HEAT engines, THERMODYNAMIC cycles
Abstract

This research encompasses the numerical analysis of trioxymethylene dimethyl ether (OME3) e-fuel on an industrial compression ignition engine, as a viable replacement for diesel fuel. The performed simulations examined single injection and multi-injection operating conditions of OME3, varying injection rates and timing. The combustion process is modeled employing two approaches: three-dimensional extended coherent flame model (ECFM-3Z) and general gas phase reactions (GGPR) with a reduced chemical kinetic mechanism. ECFM-3Z gives a faster convergence, where pretabulated autoignition and laminar flame speed databases are integrated into the model to decrease computational time. The GGPR approach is validated on the experimental values for mean pressure, temperature, and rate of released heat in the same engine with diesel fuel and then again employed on an OME3. Both approaches confirmed that a higher amount of OME3 and a prolonged injection time is needed to achieve the same released heat per cycle as diesel fuel since OME3 has a lower net calorific value. It is established that combusting OME3, a 15% higher mean pressure peak can be achieved in multi-injection case compared to the diesel fuel, by adapting the injection timing. Additionally, nitrogen oxides emissions for OME3 are also compared to the diesel case for both combustion modeling approaches. Under the context of multi-injection, the OME3 fuel results show equivalent or lesser nitrogen oxides emissions than those of diesel fuel. The outcomes yielded by the GGPR model utilizing the Lin mechanism revealed decreased temperatures, leading to correspondingly diminished concentrations of nitrogen oxide emissions in comparison with the ECFM-3Z model. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

49. Thermogravimetric and Kinetic Analysis of Waste Biomass and Plastic Mixtures.

Author

Stančin, Hrvoje, Mikulčić, Hrvoje, Manić, Nebojša, Stojiljković, Dragoslava, and Vujanović, Milan

Subjects
PLASTIC scrap, THERMOGRAVIMETRY, PLASTIC analysis (Engineering), CARRIER gas, MIXTURES, ACTIVATION energy, POLYPROPYLENE
Abstract

Thermogravimetric and kinetic analysis of biomass and plastic co-pyrolysis can provide valuable inputs for a better understanding decomposition mechanisms. Such inputs are important for selecting the appropriate process conditions but can also be helpful for process modelling. This work investigates the properties of heterogenous sawdust mixed with polypropylene and polystyrene. Thermogravimetric analysis is conducted to determine the decomposition mechanism and kinetic parameters of investigated mixtures and to derive appropriate conclusions regarding their further utilisation potential. Co-pyrolysis was performed on mixtures with the following biomass/plastic ratios: 75-25%, 50-50%, 25-75%, over a temperature range of 30-550 ℃, at four heating rates 5, 10, 20, and 30 ℃/min, with pure argon as a carrier gas. The obtained results were then subjected to comprehensive kinetic and thermodynamic analysis. The primary goal was to determine effective activation energies using model-free methods, preexponential factors, and elementary thermodynamic parameters such as enthalpy, entropy, and free Gibbs energy changes. Finally, the influence of the heating rate and mixture composition was extensively investigated by analysing calculated parameters. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results