Wyniki wyszukiwania - BazTech

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Results of using sustainable aviation fuel in transport aircraft on different flight levels and their influence on carbon-dioxide Co2 emissions

Lazic Dragan, Grujic Vladimir, Cvetkovic Dragan

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 119

105--123

EN

During the recent 40 years, the quantity of energy sources globally has been reduced, and the consequence of this situation that the oil in the world becomes more expensive. Many manufacturers have been forced to initiate the development of completely new concepts of developing commercial aircraft which would be more rational regarding fuel consumption by completely retaining the best quality of passenger services. A continuous uptrend of the propellant cost globally since 1990s has forced not only smaller companies but also the most powerful enterprises in aviation industry, such as the “General Electric”, to return to the research and development programs of Turbo Prop engines. In the case of the aircraft DHC Dash 8 Q 400, the engineering preparation of the flight for calculating the changes of travel propellant while the switch of the flight altitude was being done. By analyzing nine various levels of flight, the conclusion has been indisputably reached that regardless of the vast altitudes of a flight and the horizontal distance covered during climb and descent, the fuel consumption is significantly lower than while flying at much lower altitudes with much lower horizontal distance in climb and descent. All the indicators that have been reached undeniably confirm the fact that a flight at great altitudes enables lower consumption of fuel and less necessary time of the flights. By such analysis and setting sustainable aircraft fuels into equations, numerous improvements in the world of aviation, which directly influence the quality of life on the global level, are achieved. Likewise, it will indicate the possibility of substitution of classical hydrocarbon (fossil) fuels with biofuels which, while burning, release much lower emission of exhaust gases.

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Design and optimisation of exhaust system of light turboprop airplane

Stalewski W.

Journal of KONES

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2016

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Vol. 23, No. 2

341--348

EN

Innovative exhaust system for light turboprop airplane has been developed and optimised. Apart from the basic function of removing exhaust from turboprop engine, the system supports cooling of the engine bay. To do this, the system removes hot air from the engine bay, utilising the ejector-pump effect, where the exhaust stream generates under-pressure, sucking the hot air through the ejector slot and removes the air together with the exhaust gases. The design and optimisation of the exhaust system has been conducted based on computational methods of Computer-Aided Design and Optimisation and Computational Fluid Dynamic. Three-dimensional analysis of flow around the airplane (including effect of propeller) and inside the exhaust system was conducted by application of URANS solver ANSYS FLUENT. Using these software the trajectories of exhaust particles, both inside the exhaust ducts and outside the airplane, have been determined. Parametric model of the designed exhaust system has been developed using the in-house software PARADES. As design parameters the diameter, length and direction of exhaust ducts as well as few parameters describing a shape of the ejector, have been established. The optimisation process aimed at designing of the exhaust system, which removes the exhaust gases possibly far away from the airframe, especially during a descent flight of the airplane. Additional objectives were maximisation of the mass flow rate of hot air sucked through the ejector and minimisation of the drag force generated by external part of the exhaust system. The optimised exhaust system should have also fulfilled requirements of permissible total-pressure losses inside the exhaust ducts. The optimised exhaust system has been implemented on the light turboprop airplane and validated during flight tests.

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Aerodynamic model identification of turboprop aircraft based on flight test data

Muhammad H., Hariowibowo H.

Journal of KONES

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2013

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Vol. 20, No. 3

275---282

EN

The aerodynamic model of an aircraft can be considered as a mathematical representation of the forces and moments acting on the aircraft. These forces and moments are usually approximated by polynomials as function of aircraft’s state variables. The coefficients in the polynomials are known as the aerodynamic parameters. These aerodynamic parameters are of importance in the evaluation of aircraft performance and stability-control characteristics of an aircraft. These parameters also can be used in the design of, for example, automatic flight control systems and mathematical model of flight simulator. This paper will discuss the principles of the aerodynamic model identification of the aircraft based on flight test data using parameter identification techniques. The paper starts with discussion of a mathematical model of an aircraft. Next, parameter identification techniques will be described. Two techniques often used for estimation of the aerodynamic parameters will be discussed. Results of the modelling and estimation of the aerodynamic parameters, state trajectory of the aircraft, bias errors in the instrumentation system, and calibration factors of the vane-angle of attack from flight test data of the N-250 turboprop aircraft will be presented in this paper. Original achievement of that paper is the mathematical model of a turboprop aircraft.