Wyniki wyszukiwania - BazTech

1

Influence of oil service life on selected performance parameters of an aircraft piston engine

Trendak Michał, Czarnigowski Jacek

Combustion Engines

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2023

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R. 62, nr 3

78--83

EN

This article presents an analysis of the influence of oil service life on the performance parameters of an air-craft piston engine lubrication system used in an ultralight aircraft. The ageing of oil between oil changes causes a change in its parameters (such as density, viscosity...). These parameters have a strong influence on the level of protection of the lubricated components. Currently, in aircraft, oil changes are carried out according to a time schedule - oil is changed every fixed period (residual life) regardless of its actual condition. The task of this article is to test the possibility of an indirect assessment of oil condition based on analysis of changes in selected parameters of engine lubrication system operation during normal operation. The oil warm-up speed during the pre-start procedure and the dependence of oil pressure on engine speed were assumed for the analysis. The study was conducted on an ultralight rotorcraft during normal operation. Selected first daily flights directly after oil change, and after 17, 32, 50 and 66 hours of operation were analysed. It was shown that the warm-up rate changes in the samples analyzed, but that this change may also be due to factors other than oil operating time. In the case of the oil pressure vs. speed characteristics, different characteristics were shown for different operating time, but no specific dependencies were found.

2

Aircraft piston engine load distribution in steady state operating conditions

Czarnigowski Jacek, Trendak Michał

Combustion Engines

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2023

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R. 62, nr 2

29--35

EN

The article presents the results of statistical analysis of aircraft piston engine operational parameters during normal operating conditions. Test was carried out on ultralight gyroplane Tercel produced by Aviation Artur Trendak equipped with CA 912 ULT piston engine. Research was conducted under normal operating conditions of the autogyro and data was collected from 15 independent tests including a total of 14 flight hours conducted during training flights. Engine and flight parameters were recorded at 9 Hz during each flight using on-board Flight Data Recorded system. The data collected was subjected to statistical analysis to determine the statistical distribution of parameters defining the engine's operating condition. The analysis covered engine speed, intake manifold pressure, oil temperature, head temperature and exhaust gas temperature. The results were presented in the form of histograms showing the characteristic ranges of the parameters in aviation engine operation. An analysis of the rate of change of the analysed parameters was then carried out. This was the basis for defining the engine's steady state. The results showed that the steady state of the engine under these operating conditions accounted for more than 78% of the total engine operating time. A Power Consumption Ratio indicating the load range of the engine was determined for steady states. It was shown that most of the time the motor operates at an average load of between 50% and 80% of the nominal value.

3

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.

4

Empirical Tests of Stress in Gyroplane Rotor During Flight

Czarnigowski Jacek

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 3

107--117

EN

The paper presents the results of experimental investigations of total tensile stresses in a gyroplane’s rotor during flight. The research aimed to determine which flight maneuvers induce the greatest stress in the rotor blade and the hub bar. The object of research was an ultralight gyroplane Tercel by Aviation Artur Trendak equipped with a rotor by the same manufacturer. Measurements were taken a) at the root of the rotor blade in the longitudinal direction, at the rotor blade’s lower surface in the point where the blade is attached to the hub bar, and b) in the hub bar, on its lower surface also in the longitudinal direction. To measure the stress, the author constructed an original measuring system based on the strain gauge bridge circuit mounted on the rotor head. The tests were carried out in a wide range of maneuvers within the gyroplane’s flight envelope. The highest value of tensile stress was found to occur while rapidly reducing the horizontal velocity in steep descent.

5

The influence of the ignition control on the performance of an aircraft radial piston engine

Czarnigowski Jacek, Jakliński Piotr

Combustion Engines

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2019

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R. 58, nr 2

60--65

EN

Aircraft piston engines are built with compromise on performance and safety. The desire to achieve the highest power-to-weight ratio leads to the search for solutions that optimize the combustion process. On the other hand, the need for maximum reliability leads to the simplification of the design at the costs of performance. An example of such a compromise is the ignition system of the ASz-62IR engine. In this engine there is a double magneto ignition system with a fixed ignition advance angle. As part of the modernisation of this engine, an electronically controlled dual ignition system was developed, which allows for optimum control of the ignition advance angle in terms of power. This article discusses the results of bench tests of the ASZ-62IR-16X engine with fixed ignition timing and variable timing control. Functional parameters and toxicity of exhaust gases were analyzed.

6

Investigations of the temperature distribution in the exhaust system of an aircraft piston engine

Czarnigowski Jacek, Skiba Krzysztof, Dubieński Kamil

Combustion Engines

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2019

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R. 58, nr 2

12--18

EN

Ultralight aviation is based on piston engines requiring both performance and reliability. An important aspect is also the requirements for the installation of such an engine on an airframe, especially its heat emission. This is firstly because of the need to ensure proper engine cooling and secondly because composite elements of the airframe skin are not exposed to excessive overheating. For this purpose, bench tests of the temperature distribution of the exhaust system of ROTAX 912 engine were carried out. Measurements were taken at 6 points of the exhaust system, where the temperature of the exhaust gases and exhaust pipes were measured. The tests covered a wide range of engine operation. The paper presents the temperature distribution at selected points in relation to the engine speed and load.