Papers by Branislav Jojic
DOAJ (DOAJ: Directory of Open Access Journals), 2014
Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing b... more Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing biomass, coal and other potentional fuels. Although its composition depends on previous process, synthetic gas is generally mixture of hydrogen, carbon-monoxide and methane in different ratios. The idea to use gases from waste as a fuel for gas-turbine generator producing electric energy is very attractive but also challenging. In this paper is presented modification of an existing turbo-shaft engine in order to be capable to operate with synthetic gas. Together with problems such as low heating value of the gas, different stochiometric ratio of gas and air compared to kerosene/air combination and high hydrogen contents, the engineering task was to do it with minimum number of changes. Problem is solved by adjusting existing airblast atomizers and experimentally verified.
23rd Joint Propulsion Conference, Jun 29, 1987
Experimental and Computational Investigations in Engineering, 2020
Subsonic ramjets, due to its simplicity, nowadays could be very attractive for expendable unmanne... more Subsonic ramjets, due to its simplicity, nowadays could be very attractive for expendable unmanned applications. However, due to very low efficiency at low Mach numbers, practically there isn't any important application at subsonic speed. In 50's subsonic ramjet was used for tip jet applications. Later in 70's there was a study of Fan Augmented Ramjet (FARJ) where a fan was intended to be powered by a piston engine, both in subsonic and supersonic regimes. Almost at the same time it was analyzed ejector augmented subsonic ramjet. Both of these studies did not find real application of such engines. Finally, there was an attempt for the use of an Electric Ducted Fan, used in RC models, with a combustor but exit fan pressure was almost at atmospheric pressure which results in very low efficiency. This paper presents a study of propulsion system which consists of a pitot intake, electrically powered compressor/fan, combustor and nozzle (Electrically Fan Augmented Ram Jet, EFARJ). The electric motor connection to the compressor/fan is direct, without gearbox, which implies usage of a high-speed brushless motor. Such propulsion system is compared to pure ramjet and finally it is compared to performances of small expendable turbojet. Comparison is made regarding costs, weight and thrust/consumption. The study shows that the proposed propulsion system could be competitive for expendable, low speed and short duration applications.
Tehnicki vjesnik - Technical Gazette, 2015
Original scientific paper This study proposes an innovative test stand design to accurately measu... more Original scientific paper This study proposes an innovative test stand design to accurately measure rocket motor thrust vector during its operation. Test stand design is clearly presented as well as procedure and mathematical model for its calibration. A method of processing data obtained from the experiments and the results of the jet tab system for thrust vector control are presented in detail. Experiments have shown that the test stand is highly functional and the results obtained have excellent repeatability and matching with the results of the other authors who have used different construction test stands for measurement of the same or a similar mechanism for thrust vector control.
Tehnicki vjesnik-Technical Gazette, 2015
Original scientific paper Physical model of spoiler and dome deflector thrust vector control (TVC... more Original scientific paper Physical model of spoiler and dome deflector thrust vector control (TVC) system was established considering previous and current research observations. According to logic of physical model an engineering mathematical model is derived. Model algorithm and results were analysed and explained. Finally, model data were confirmed with real motor tests.
FME Transaction, 2014
Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing b... more Synthetic gas is nowadays the co-product of procceses such as waste gasification and processing biomass, coal and other potentional fuels. Although its composition depends on previous process, synthetic gas is generally mixture of hydrogen, carbon-monoxide and methane in different ratios. The idea to use gases from waste as a fuel for gas-turbine generator producing electric energy is very attractive but also challenging. In this paper is presented modification of an existing turbo-shaft engine in order to be capable to operate with synthetic gas. Together with problems such as low heating value of the gas, different stochiometric ratio of gas and air compared to kerosene/air combination and high hydrogen contents, the engineering task was to do it with minimum number of changes. Problem is solved by adjusting existing airblast atomizers and experimentally verified.
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Papers by Branislav Jojic