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Limits of the variability of the operating states of the ultralight autogyro engine

Jakliński Piotr, Ścisłowski Karol

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 6

223--234

EN

The publication presents an analysis of the operating conditions of the propulsion system of an ultralight autogyro during flights of various lengths and dynamics. This analysis is aimed at demonstrating the limits of variability of engine operation to determine the boundary conditions of aircraft engine operating conditions in actual operation. This parameter, in turn, will enable the effective use of the advantages of aircraft hybridization depending on the type of mission. The research data was collected from 10 different flights of the TERCEL wind turbine. MAP, RPM, flight altitude, horizontal and vertical speed, etc. were extracted from the on-board FDR (Flight Data Recorder) and then analyzed. The flights were classified as short SF (<30 min) and long LF (>30 min). The defined parameters are steady state and transient engine operation, IDLE, low load LL, high load HL and WOT as well as acceleration and deceleration. The analysis of the data shows that for the short flights, the share of steady state is about 80% and increases to more than 90% for the long flights. For the short flights, the share of acceleration accounts for about 60% of transient states and also increases to more than 65% for the long flights. For the short flights, IDLE, LL and WOT have a fairly significant share and amount to 32%, 36.1% and 7.5%, respectively, while they are increasingly marginalized by the increasing share of HL as the flight lengthens. For the long flights, HL's share was almost 70%.

2

Study of the effect of ignition crank angle and mixture composition on the performance of a spark-ignition engine fueled with ethanol

Jakliński Piotr, Czarnigowski Jacek, Ścisłowski Karol

Combustion Engines

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2024

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R. 63, nr 2

56--63

EN

The publication presents the results of the measurements of the operating parameters of a spark-ignition engine fueled with 95-octane unleaded gasoline (ES95) and ethyl alcohol, approx. 92%. The measurements were carried out at a constant load: an engine speed of 1500 rpm and a constant pressure in the intake system - MAP = 0.45 bar. For each type of fuel, the measurements were carried out in two series for two variables. The ignition crank angle was varied in the range of 0˚÷40˚ and the mixture composition λ in the range of 0.85-1.25. The recorded engine performance parameters included torque, intake manifold pressure, intake air temperature, exhaust gas temperature and temporal fuel consumption; and exhaust gas composition was examined in terms of carbon monoxide, hydrocarbons and nitrogen oxides. The study showed that an ethanol-fueled engine has lower average efficiency compared to a gasoline one. The highest efficiency for ethanol was obtained for rich mixtures in the range λ = 0.85-1.0 and at high ignition advance angles. The use of alcohol fuel showed a very favorable effect on the composition of exhaust gas and a significantly lower content of harmful exhaust components was demonstrated. For the same operating points, carbon monoxide content was reduced by an average of 15%, and hydrocarbons and nitrogen oxides by an average of 80%.

3

Analysis of the Operating Conditions of the ASz-62IR Engine During Flight

Jakliński Piotr, Czarnigowski Jacek, Ścisłowski Karol

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 8

56--72

EN

The article describes the results of an analysis of the states and operating conditions the ASz-62 IR-16E engine. The tests were carried out on an AN-2 aeroplane with the ASz-62IR-16E engine. The purpose of this study was to determine the contribution of static and dynamic engine operating states during flight. The engine operating parameters were recorded at a frequency of 16 Hz for over 7 hours of flight. The engine operating points defined by two parameters, i.e. engine speed and intake manifold pressure were analysed, and the mean values, standard deviations and histograms of the distributions of these parameters were determined. The distribution of the occurrence of various operating states, i.e. steady states and transients was also analysed for low, medium and high load, and for IDLE and WOT. The article describes the contribution of the individual engine operating states to the total flight time. The results obtained for the aircraft engine are compared with those obtained for automotive vehicle engines and described in the paper. The study shows that most of the operating time of the ASz-62IR-16E aircraft engine was in steady-state conditions - about 90% of this time, whereas steady-state operating conditions for the automotive engine account for about 80% of the driving time. For the aircraft engine, more than 65% of operating time is heavy load. Small and medium loads account for 10% and 25% of operating time, respectively. In the case of the car engine, only about 5% of operating time is heavy load, while the major part of operating time is under light (about 40%) and medium (about 55%) load. Under idling conditions, the aero-engine's operating time was about 6.2 %, i.e. about twice shorter than that of the car engine (about 13.2 %). Under WOT conditions, the aircraft engine had an operating time of 1.3 %, while for the car engine this condition was extremely rare - about 0.1 %. It was also shown that the ASz-62IR-16E aircraft engine of the AN-2 aircraft in real flight conditions has a specific, most frequently used operating point lying in the range of the values: n=1800÷1900 RPM and MAP=0.8÷0.95 Bar.

4

An assessment of the transient effect on helicopter main rotor stability and power demand

Raczyński Radosław, Siadkowska Ksenia, Ścisłowski Karol, Wendeker Mirosław

Combustion Engines

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2022

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R. 61, nr 4

23--28

EN

The researched object is a helicopter main rotor with blades of variable geometric twist characteristics. Variable torsion refers to systems of actuators made of shape memory alloys. The presented numerical analyses allow for evaluating both the dynamics of the rotor in transient states, i.e. in the zone between the static phase and the full activation phase and the impact of the change on the pulsation of the amplitude of the necessary power generated by the rotor corresponding the flight state, and thus covering the demand by the disposable power generated by the engine. This study follows a methodology of numerical analyses based on Multi Body Dynamics and the Finite Element Method and uses fluid mechanics elements and algorithms to analyze lift generation, compiled in a single computational environment referring to the same period of time.

5

Strength analysis of a prototype composite helicopter rotor blade spar

Kliza Rafał, Ścisłowski Karol, Siadkowska Ksenia, Padyjasek Jacek, Wendeker Mirosław

Applied Computer Science

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2022

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Vol. 18, no. 1

5--19

EN

This paper investigates the strenght of a conceptual main rotor blade dedicated to an unmanned helicopter. The blade is made of smart materials in order to optimize the efficiency of the aircraft by increasing its aerodynamic performance. This purpose was achieved by performing a series of strength calculations for the blade of a prototype main rotor used in an unmanned helicopter. The calculations were done with the Finite Element Method (FEM) and software like CAE (Computer-Aided Engineering) which uses advanced techniques of computer modeling of load in composite structures. Our analysis included CAD (Computer-Aided Design) modeling the rotor blade, importing the solid model into the CAE software, defining the simulation boundary conditions and performing strength calculations of the blade spar for selected materials used in aviation, i.e. fiberglass and carbon fiber laminate. This paper presents the results and analysis of the numerical calculations.

6

Analysis of propulsion units dedicated to test stands for aviation systems

Siadkowska Ksenia, Czajka Błażej, Ścisłowski Karol, Wendeker Mirosław

Combustion Engines

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2021

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R. 60, nr 2

39--43

EN

This paper presents an analysis of selected propulsion units dedicated to test stands for unmanned aircraft systems. It focuses on engines suitable for aircraft with a maximum take-off mass up to 150 kg. The study includes an analysis of propulsion units that can be used to power systems on stationary test stands dedicated to advanced research and measurement of prototype aerospace technologies intended for use in rotorcraft. The analysis of propulsion units shows that electric units are a better choice for powering UAV rotorcraft test stands. Their main advantages include the possibility to simplify the construction of the device by eliminating gears and to mount the motor in a vertical position, simpler power supply, cooling and control systems and the lack of an exhaust system. Additional advantages are undoubtedly lower vibration generation, cheaper and easier operation as well as better comfort.

7

Analysis of operating parameters of the aircraft piston engine in real operating conditions

Czarnigowski Jacek, Rękas Daniel, Ścisłowski Karol, Trendak Michał, Skiba Krzysztof

Combustion Engines

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2021

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R. 60, nr 4

83--89

EN

The article presents the results of analysis of operational parameters of piston engine CA 912 ULT which is a propulsion system of ultralight gyroplane Tercel produced by Aviation Artur Trendak. Research was conducted under normal operating conditions of the autogyro and data was collected from 20 independent tests including a total of 28 flight hours, divided into training flights and competition flights. Engine speed, manifold air pressure and temperature, fuel pressure, injection time, and head temperature were recorded at 9 Hz during each flight. Collective results were presented to show the statistical analyses of the individual parameters by determining the mean values, standard deviations and histograms of the distribution of these parameters. Histograms of operating points defined by both engine speed and manifold air pressure were also determined. Analyses of the engine dynamics as a distribution of the rate of change of the engine rotational speed were also carried out. It was shown that the engine operating points are concentrated mainly in the range of idle and power above 50% of nominal power. The most frequent range is 70-80% of nominal power. It was also shown that the dynamics of engine work in real operating conditions is small. It was also shown that the way of use significantly influences the distribution of operating points. During training flights, an increase in the number of take-offs and landings causes an increase in the amount of engine work at take-off and nominal power and at idle.

8

Bench Tests for Exhaust Gas Temperature Distribution in an Aircraft Piston Engine with and without a Turbocharger

Czarnigowski Jacek Andrzej, Skiba Krzysztof, Rękas Daniel, Ścisłowski Karol, Jakliński Piotr

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no. 3

155--166

EN

In ultralight aviation, a very important engine parameter is the power-to-weight ratio. On the one hand, there is a tendency to minimize the size and weight of engines, and on the other hand, there is a demand to achieve the highest possible power by using supercharging systems. Increasing power brings many benefits, but it also increases temperature in the exhaust system, posing a threat to delicate parts of the ultralight aircraft fuselage. Therefore, it is necessary to control temperature values in the engine exhaust system. This article presents the temperature distribution in the exhaust system of an aircraft engine by the example of a four-cylinder Rotax 912 engine with an electronic fuel injection system. The research was conducted in two stages: measurements were made first for the engine without a turbocharger with an original exhaust system and later for its modified version with an added turbocharger system. The paper presents a comparative analysis of exhaust gas temperatures measured at three points: 30, 180 and 1000 mm from the cylinder head. The tests were conducted for the same preset engine operating conditions at constant speed and manifold air pressure. It has been shown that the exhaust temperature in the exhaust manifold decreases with the distance from the cylinder head. The highest gradient, over three times higher than the gas temperature from 589.9 °C to 192.3 °C, occurred in the manifold with a turbocharger for 2603 RPM and 31 kPa of manifold air pressure. The introduction of turbocharging causes an increase in exhaust gas temperatures before the turbocharger by an average of 12%, with this increase being greater for operating points of higher inlet manifold pressure. Turbocharging also causes a significant decrease in exhaust gas temperatures behind the turbocharger and the silencer because the temperature drops there by an average of 25%.