It is forecast that in the future, alternative fuels derived from non-petroleum sources will become the basic propellant for turbine aircraft engines. Currently, five types of aviation turbine fuel containing synthesized hydrocarbons are certified and accepted, and allow adding a maximum of 50% of synthetic component to conventional fuel. The experimental performance and the emission characteristics of a turbojet engine were investigated in this paper. The studies were conducted with the use of a miniature turbojet engine, which is the main component of a laboratory test rig. The test rig is an interesting solution for engine research, due to the fact that studies concerning fullscale aircraft engines are very complex and expensive. The literature of the subject contains many papers using smallscale turbojet engines for testing alternative fuels. However, most of them concern components of fuels, e.g. biodiesel, butanol, which do not have direct application in aviation. Two different fuel samples, a conventional Jet A-1 fuel and a blend of 48% synthesized paraffinic kerosene from hydroprocessed esters and fatty acids process with Jet A-1 were tested. This process is one of the routes of producing alternative fuel for aviation, approved by ASTM standard. The test rig studies were performed according to a specific profile of engine test, which models different modes of a turbojet engine's operation. The obtained results are compared in relation to the results for neat Jet A-1 fuel and then discussed.

This paper presents a methodology developed to measure exhaust gas emissions during operation of a miniature turbojet engine, using a laboratory test rig. The rig has been built for research and development works aimed at modelling and investigating processes and phenomena occurring in jet engines. The miniature jet engines, similarly to full–scale ones used commonly in air transport, are characterized by variable exhaust gas emissions, depending on engine operating parameters. For this reason, an attempt has been made to determine the characteristic features of miniature engine operation modes and to define the variability of operation parameters and exhaust gas emissions as a function of time. According to the authors, the preliminary tests allowed for defining specific profile of engine test, which enables proper measurement regarding exhaust gas emissions using the miniature jet engine. The paper also presents test results for Jet A-1 fuel, according to the used methodology.

This article presents laboratory test rig with a miniature turbojet engine (MiniJETRig -Miniature Jet Engine Test Rig), that was built in the Air Force Institute of Technology. The test rig has been developed for research and development works aimed at modelling and investigating processes and phenomena occurring in full scale jet engines. In the article construction of a test rig is described, with a brief discussion on the functionality of each of its main components. Additionally examples of measurement results obtained during the realization of the initial tests have been included, presenting the capabilities of the test rig. Streszczenie: Tematem publikacji jest laboratoryjne stanowisko hamowniane MiniJETRig (Miniature Jet Engine Test Rig) zbudowane w oparciu o miniaturowy silnik odrzutowy, wytworzone w Instytucie Technicznym Wojsk Lotniczych.Stanowisko przeznaczone jest do realizacji prac badawczorozwojowych, mających na celu modelowanie oraz badanie procesów i zjawisk zachodzących w rzeczywistych silników odrzutowych. W artykule przedstawiono budowę stanowiska wraz z krótkim opisem funkcjonalnym poszczególnych elementów składowych. Zaprezentowano również przykładowe wyniki pomiarowe uzyskane podczas realizacji wstępnych testów hamownianych, prezentujące możliwości badacze stanowiska. Słowa kluczowe: miniaturowy silnik odrzutowy, proces spalania, paliwa lotnicze, gazy spalinoweThe laboratory test rig with miniature jet engine to research aviation fuels... Laboratoryjne stanowisko hamowniane miniaturowego silnika odrzutowego...

In the next decade, due to the desire for significant reduction in the carbon footprint left by the aviation sector and the development of a sustainable alternatives to petroleum, fuel from renewable sources will play an increasing role as a propellant for turbine aircraft engines. Currently, apart from five types of jet fuel containing synthesized hydrocarbons that are certified by the ASTM D7566 standard, there is yet another synthetic blending component that is at the stage of testing and certification. Hydroprocessed esters and fatty acids enable the production of a synthetic component for jet fuel from any form of native fat or oil. Used feedstock affects the final synthetic blending component composition and consequently the properties of the blend for jet fuel and, as a result, the operation of turbine engines. A specialized laboratory test rig with a miniature turbojet engine was used for research, which is an interesting alternative to complex and expensive tests with full scale turbine engines. The results of this study revealed the differences in the parameters of engine performance and emission characteristics between tested fuels with synthetic blending components and neat jet fuel. The synthetic blending component was obtained from two different feedstock. Noticeable changes were obtained for fuel consumption, CO and NOx emissions. With the addition of the hydroprocessed esters and fatty acids (HEFA) component, the fuel consumption and CO emissions decrease. The opposite trend was observed for NOx emission. The tests presented in this article are a continuation of the authors’ research area related to alternative fuels for aviation.

Purpose The purpose of this paper is to examine the toxicological impacts of exhaust generated during the combustion process of aviation fuel containing synthesized hydrocarbons. Design/methodology/approach Tests on aircraft turbine engines in full scale are complex and expensive. Therefore, a miniature turbojet engine was used in this paper as a source of exhaust gases. Toxicity was tested using innovative BAT–CELL Bio–Ambient Cell method, which consists of determination of real toxic impact of the exhaust gases on the human lung A549 and mouse L929 cells. The research was of a comparative nature. The engine was powered by a conventional jet fuel and a blend of conventional jet fuel with synthesized hydrocarbons. Findings The results show that the BAT–CELL method allows determination of the real exhaust toxicity during the combustion process in a turbine engine. The addition of a synthetic component to conventional jet fuel affected the reduction of toxicity of exhaust gases. It was confirmed for both tested cell lines. Originality/value In the literature related to the area of aviation, numerous publications in the field of testing the emission of exhaust gaseous components, particulates or volatile organic compounds can be found. However, there is a lack of research related to the evaluation of the real exhaust toxicity. In addition, it appears that the data given in aviation sector, mainly related to the emission levels of gaseous exhaust components (CO, Nox and HC) and particulate matters, might be insufficient. To fully describe the engine exhaust emissions, they should be supplemented with additional tests, i.e. in terms of toxicity.

Alternative fuels containing biocomponents produced in various technologies are introduced in aviation to reduce its carbon footprint but there is little data describing their impact on the performance and emissions of engines. The purpose of the work is to compare the performance and gas emissions produced from two different jet engines—the GTM-140 microturbine and the full-size DGEN380 turbofan, powered by blends of Jet A-1 and one of two biocomponents: (1) Alcohol-to-Jet (ATJ) and (2) Hydroprocessed Esters and Fatty Acids (HEFA) produced from used cooking oil (UCO) in various concentrations. The acquired data will be used to develop an engine emissivity model to predict gas emissions. Blends of the mineral fuel with synthetic components were prepared in various concentrations, and their physicochemical parameters were examined in the laboratory. Measurements of emissions from both engines were carried out in selected operating points using the Semtech DS gaseous analyzer and the EEPS spectrometer. The impact of tested blends on engine operating parameters is limited, and their use does not carry the risk of a significant decrease in aircraft performance or increase in fuel consumption. Increasing the content of biocomponents causes a noticeable rise in the emission of CO and slight increase for some other gasses (HC and NOx), which should not, however, worsen the working conditions of the ground personnel. This implies that there are no contraindications against using tested blends for fuelling gas-turbine engines.

Purpose The purpose of this paper is to present an assessment method of the toxicity emission evaluation during combustion in the miniature turbojet engine. Design/methodology/approach A small-scale turbojet engine was used for the research because measurements on real aircraft turbines are complex and expensive. The experiment was performed in accordance with innovative BAT – CELL Bio – Ambient Cell method which consists of determination of virtual toxic impact of the gas mixture on the living cells; it is therefore a direct method. The most significant innovation of this method is that, during the test, which consists of exposing the cells to the gas mixture, the cells are deprived of culture fluid. Findings The preliminary analysis shows that the method used here allows to determine the virtual impact of the gases on the human respiratory system and skin. It could be useful in defining the arduousness of an airport. The obtained results show that both of exhaust gases represent similar toxicity. Practical implications The new in vitro method allows to determine the virtual impact of the gases on the human respiratory system and skin. Significant potential for further research not only on the miniaturised engines, but also in the case of real objects, as this method does not have to be performed in a laboratory. Originality/value The work presents potential application of the innovatory method for exhaust gases toxicity evaluation in jet engines, which could be useful in defining the arduousness of an airport.

No abstract