Aircraft Piston Engine Research Articles

Problems of aviation leaded gasoline application on aircraft

Special aviation gasoline with specified operational properties is used for aircraft piston engines. The level of operational properties indicators is specified by the special additives introduction. One of these additives is an antiknock additive – tetraethyl lead. The influence of tetraethyl lead contained in aviation gasoline on the oil systems of aircraft piston engines operation are shown in the article. The insignificant content of TEL decomposition products in aviation oils sharply worsens their pumpability and leads to complete fine oil filters clogging in a few minutes of engine operation, which is negative from the point of view of flight safety.

Research of an aircraft engine cylinder assembly integrity assessment – Thermomechanical FEM analysis

Failures of aircraft piston engine components are a common occurrence in practice. During operation, cylinder heads are components that are exposed to multiaxial thermomechanical loads leading to fatigue. Therefore, predicting the lifetime of the cylinder heads exposed to such loads is one of the most important tasks to ensure engine quality, durability and safety. This paper is the continuation of a comprehensive research of the Lycoming IO-360-B1F aircraft engine cylinder head failure. The failure of this type has already occurred during flight and about 50 failures like this have been registered from around the world, some of them with a fatal outcome and therefore require detailed research. This research includes the numerical stress and fatigue analysis of the cylinder assembly exposed to high cycle mechanical and thermal loads that failed due to a crack appearance on the cylinder head. A 3D cylinder assembly model was created. The locations with the highest stress values, both mechanical and thermal, were determined using numerical analysis. Also, the lifetime of the cylinder assembly has been determined, i.e. an integrity assessment has been carried out which will contribute to the consideration of the crack appearance problem. Defining the coupled thermomechanical load of the cylinder assembly in the numerical analysis gives special significance to this paper. The results obtained will serve to analyze the crack propagation in the cylinder head which is going to be the subject of further research.

Development prospects of aircraft piston engine - building in Russia

Development prospects of aircraft piston engine - building in Russia

Development of a boost system turbocompaund piston engine

The requirements for modern engines are constantly being tightened in terms of ensuring economic and environmental parameters. Thermodynamic analysis shows that approximately 30-40% of fuel energy is emitted into the environment by exhaust gases. For this reason, obtaining additional energy from exhaust gases is a promising way to significantly improve the thermal efficiency of the engine. Methods for generating additional energy from exhaust gases include: turbocharging, turbocompound, Brighton cycle, Rankine cycle and thermoelectric generators. These methods showed an increase in thermal efficiency, which vary from 2-20%, depending on the design of the system, the quality of energy recovery, component efficiency and implementation. In this work theme of one of the promising options for energy saving in piston engines will be revealed. Unfortunately, the topic turbocompounding in Russia is poorly studied, there are no methods for developing these systems, recommendations for selecting boost units. The aim of this work is to create a turbocompound system for boosting an aircraft engine. In accordance with the goal, the following tasks are formulated and solved: studied domestic and international experience in creating turbocharging systems for turbocharged piston engines; a methodology has been developed for creating turbocharged boost systems for internal combustion engines; recommendations were developed to coordinate the joint operation of a turbocompressor and a power turbine, as well as a turbocompound system with an engine; developed recommendations for choosing a method for regulating turbocompound boost systems. Based on the developed methodology and recommendations, the calculation of the pressurization parameters of the APD - 500 diesel aircraft piston engine with a power of 368 kW was performed. The required characteristics of the blade machines were determined and the required sizes were selected. The choice of turbochargher was made by superimposing the flow characteristics of the APD-500 engine on the characteristics of the compressor stage of the turbochargher. The parameters of the power turbine were calculated, the required gear ratio of the power turbine gearbox was determined.

Modeling and simulation of ventilation and cooling of aircraft piston engine based on genetic algorithm

With the gradual orderly opening of low-altitude areas and the increasing number of private aircraft, the general aviation industry has ushered in new opportunities for development. Ventilation and cooling optimization of the piston aeroengine has become a very important field in general aviation enterprises. The traditional aircraft engine design method and control system do not consider the coupling between aircraft and engine, which can not meet the needs of development. Therefore, an optimization method for the ventilation and cooling of aircraft piston engines based on a genetic algorithm is proposed. Firstly, the engine cooling model is constructed, the ventilation and cooling principles of aircraft piston engines are analyzed, and then the genetic algorithm is used to optimize the ventilation and cooling program of the aircraft piston engine. The results show that the method can effectively optimize the ventilation and cooling scheme of the aero piston engine. During the optimization process, the average convergence value is always greater than 95.00%. Under different working conditions, the maximum failure rate of the optimized ventilation and cooling scheme is 0.03. The maximum failure rate is lower than that of similar methods.

Application prospects of turbo - compound aircraft piston engines

Application prospects of turbo - compound aircraft piston engines

Разработка загущенного полусинтетического масла м-5з/20 аэро для авиационных поршневых четырехтактных бензиновых двигателей беспилотных летательных аппаратов

Nowadays, the creation of remotely-piloted aerial vehicles for various purposes is regarded as one of the most relevant and promising trends of aircraft development. FAU "25 State Research Institute of Chemmotology of the Ministry of Defense of the Russian Federation" have studied the operation features of aircraft piston engines and developed technical requirements for motor oil for piston four-stroke UAV engines, as well as a new engine oil M-5z/20 AERO in cooperation with NPP KVALITET, LLC. Based on the complex of qualification tests, the stated operational properties of the experimental-industrial batch of M-5z/20 AERO oil are generally confirmed.

Особенности рабочего процесса поршневого двигателя при работе на керосине

For aircraft in light multi-purpose aviation, piston engines are considered more efficient than gas turbine. The main technical requirement for such engines is to ensure trouble-free operation with the best possible fuel efficiency. At the same time, there are no requirements to emission of harmful substances in exhaust fumes except for the absence of visible smoke. When developing multi-purpose aircraft piston engines, it is important to ensure their multi-fuel operation, including opera-tion on TS-1 kerosene and diesel fuel. But the issues associated with setting engine control algo-rithms for operation on TS-1 kerosene are practically unexplored. In order to refine the control algo-rithms, the flow of the working process using such fuel was studied in this work. The effect of se-quencing the working process stages on the formation of the ignition delay period was shown. Based on the analysis of the factors affecting the ignition delay period, a map of the fuel injection advance angle values was generated. According to the experimental data, the activation energy of pre-flame reactions was adopted, which for kerosene TS-1 was 23–28 kJ/mol.

AVIATION ENGINES DIAGNOSTICS BY ESTIMATING THE METAL CONTAMINATION IN OILS

Current trends of civil aviation development show a significant increase in the number of aircraft with aircraft piston engines. The Ministry of Transport of the Russian Federation is preparing a draft order on amendments to the Federal aviation rules for the preparation and performance of flights in civil aviation (FAP-128), which stipulate for simplified procedures of paid excursion flights implementation for light and ultralight aircraft and helicopters. It is obvious that this circumstance will significantly affect the expansion of the fleet of these aircraft. Accordingly, the state of piston engines operating on aviation gasoline value questions are becoming increasingly relevant. The current problems of aviation engines diagnostics by metal contents in oils are observed in the article. Their bugs, possible ways of solving this problems and bugs, actual developments in this direction are shown. The application examples of early diagnostic methods using the automated diagnostic complex “Prisma” are shown. The oil samples taken from An-2 aircraft АШ-62ИР piston engine analyses results attract the most interest. They show that with proper training of personnel the valuable information coming from the oil samples can be a source of important conclusions not only in aircraft engines accessories and assemblies state value, but also others systems, and also conclusions about the quality of fuel and lubricants used. Estimating the residual life method of the engine at various stages of its operating time on the metal content in the oils and the procedure for oil selecting, allowing to obtain reliable results, are suggested.

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

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.

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

Ultralight aviation is based on piston engines requiring both performance and reliability. An important aspect is also the require-ments 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.

Failure analysis of high pressure fuel pump on piston aircraft engine

High Pressure Pump (HPP) failure leads to a sudden fuel cut off, during the training flight. To investigate the root cause of HPP failure, two more aged fuel pump (TSN 600h), fro m the same flight academy, was received. The failed pump and aged pumps were disassembled and analyzed by optical microscope (OM), scanning electronmicroscope (SEM) and metallographic analysis. Results showed that the metallographic technology of the three pumps were the same. Foreign debris found in the failed fuel pump stuck one plunger. At next revolution the rotor was pushing hard against the follower plate causing a sheared plunger and cylinder. Subsequent frag ments leads to the other two plungers’ failure. Due to more and more debris, other parts of the pump fail as a secondary failure. Friction or stuck marks in the failed pump and the other two aged pumps indicated that it is more likely to have axial scratches in operation base Z. This operation base is close to desert.

Simulation Research of Aircraft Piston Engine Rotax 912

This paper reports the results of simulation works of Rotax 912 aircraft piston engine, which is a basic unit in most ultra-light aircrafts. The method for preparing the model aircraft engine operation process was presented. Simulation tests were carried out in the AVL Boost programme. The programme allows a full use of zero-dimensional and one-dimensional modelling. It also allows a comparison of other engine models. The developed model has enabled us to simulate the flow of air through the inlet pipes, carburettors, valves and combustion process. The preparation of the model required us to enter parameters that are not available in the manufacturer's catalogue, therefore, necessary measurements and analysis of the engine parts were carried out on a laboratory bench. The calculations in the AVL Boost programme were carried out in the conditions determined for the selected BMEP values with the objective of characterising the engine performance by determining its power, torque and fuel consumption.

THE STUDY ON LOADS ON AN AIRCRAFT PISTON ENGINE CONTINENTAL MOTORS IOF-240-B5B IN TRAINING FLIGHTS

This investigation presents the development of a model of a flight envelope for a piston engine aircraft. The study covers performing necessary tests and measurements of the selected operating parameters of the engine piston and an analysis of the results. The paper describes also a mission and aircraft manoeuvres. This investigation enables us to study loads on an aircraft piston engine, i.e. Continental Motors IOF-240-B5B, mounted in the Liberty XL2 by Liberty Aerospace.

The Research of Acoustic Emission of a Low-Power Aircraft Engine

Abstract This paper presents the methodology and investigation of the sound power level produced by a radial piston aircraft engine operating at varied speeds. The research model aircraft engine of a maximum power of 5.5 kW with a two-bladed airscrew was placed on a test bend. Its sound power level was calculated from the sound pressure level measured at 9 measurement points distributed on a hemispherical surface in a confined space in line with PN-EN 3744. Mean sound power generated by the ASP FS400AR engine is 96 dB at idle (2,880 rpm) and 105 dB at a cruising speed (4,740 rpm). Accordingly, it can be concluded that a sound level meter registered a higher sound power level at the points in front of the model aircraft engine than at the points behind it, whereas the lowest sound power level was registered directly above the engine.

Design and optimization of a novel electrically controlled high pressure fuel injection system for heavy fuel aircraft piston engine

The heavy fuel compression ignition engines are widely equipped as aircraft piston engines. The fuel injection system is one of the key technologies that determines the performance of engine. One of the main challenges is to precisely control the injected fuel quantity and flow rate in the presence of pressure fluctuation. This challenge is even more serious for heavy fuel. An original design for electrically controlled high pressure fuel injection system called Multi-Pump-pressure-reservoirs fuel injection System (MPS) was demonstrated to reduce the pressure fluctuation and help keep injection stable. MPS was compared with an ordinary high pressure Common Rail fuel injection System (CRS). This work established one-dimensional AMESim and mathematical models for both CRS and MPS to study the effect of different structures and geometric parameters on the pressure fluctuations. The calculations show that the average fuel pressure fluctuation of MPS can be reduced by 57% for the crankshaft speed of 1900 r/min, and the pressure fluctuation before injection reduced by 100%. It is concluded that the pressure performance of MPS is less sensitive to pressure reservoir volume than that of CRS, and there is an opportunity for further volume reduction.

Review of Alternative Fuel Initiatives for Leaded Aviation Gasoline (AVGAS) Replacement

Tetraethylead (TEL) is an additive in aviation gasoline (AVGAS) fuels to help suppress knock. Knock produces very high pressure inside the engine which can cause severe damage easily. Without the addition of TEL, the octane levels will be too low for some engines. Using a lower octane fuel than required level could lead to engine failure in piston aircraft engines. This is because Piston aircraft engines operate at higher power settings and temperatures. Friends of the Earth (FOE) filed a ‘‘Petition for Rulemaking Seeking the Regulation of Lead Emissions from General Aviation Aircraft Under Clean Air Act” to conduct a finding that lead emissions from general aviation aircraft endanger public health. FOE insisted to issue a proposed emission standard for lead from general aviation aircraft under the Clean Air Act (CAA). In 2008, EPA decreased the level of the primary National Ambient Air Quality Standard (NAAQS) for lead from 1.5 micrograms per cubic meter (µg m-3) to 0.15 µg m-3 in order to provide increased protection for children and other at-risk populations against an array of adverse health effects. In this study, a comprehensive review will be conducted to analyse the replacement fuels introduced or tested or in use around the globe that has been used to further reduce or totally eliminate TEL from avgas 100LL. This paper assists aviation research students to further research and gain comprehensive knowledge on AVGAS, the problems on AVGAS and alternative fuel initiatives around the globe. If replacement for leaded fuels are tested and proven for drop-in replacement, the general aviation community can continue to thrive for decades to come with a renewable resource that is cleaner for the environment. Lead emissions should also be given equal concentration along with emissions of carbon dioxide, carbon monoxide, oxides of nitrogen and other particulates emissions in aviation with proper studies and findings to help the elimination ef

Emissions of piston engine aircraft using aviation gasoline (avgas) and motor gasoline (mogas) as fuel – a review

There are two categories of aircraft engines, namely, piston and gas turbine engines. Piston engine extracts energy from a combustion compartment through a piston and crank apparatus that engages the propellers, which in turn, provides an aircraft the needed momentum. On the other hand, gas turbine engine heats a compressed air in the combustion compartment resulting in propulsion that drives an aircraft. Piston engine aircrafts might appear small but together thousands of piston engine aircraft, which encompasses a bulk of the general aviation fleet, present a considerable health threat. That is because these aircraft, which depend on avgas and mogas to run, comprise major remaining sources of lead emissions. People exposed to even small levels of lead, particularly children, have tendencies to suffer from cognitive and neurological harm. Dissimilar from commercial airliners that do not utilize leaded fuels, piston engine aircraft account for nearly half of the lead discharge in skies. But, what is the extent of the impact caused by these airborne emissions on the country’s economy and public health? To answer this query, a thorough literature review on emissions of piston engine aircraft ought to be undertaken. This article conducts a literature review on emissions of piston engine aircraft using avgas as fuel and mogas as fuel.

A review of vapour lock issues during motor gasoline or automotive gasoline usage in piston engine aircraft

Since there is a developing practice of utilizing automotive fuels as flight fuel, there are higher chances of dangerous scenarios, particularly in the operation of piston aircraft engines. The use of motor vehicle gas (MOGAS) or aviation gas (AVGAS) in the operation of aviation piston engine increases the risk of vapour locking. A statistical examination of European aviation industry indicates that around 20,000 aircraft are affected either specifically or conceivably by the different negative impacts of gasoline blended with ethanol. Particularly, for most contemporary carburettor engines, there are risks associated with ethanol-admixed fuels that have potential to upset engine operation. The danger of vapour locking, which is the generation of gas bubbles inside the fuel system causing an impairment of fuel movement in the engine, is well documented particularly by studies on aircraft using MOGAS. Contrasted with AVGAS, MOGAS is inclined to demonstrate this phenomenon. Vapour lock is perhaps the leading serious problem that ought to be addressed if MOGAS is to be used as a substitute for AVGAS. Vapour lock problem is critical because it causes malfunctions to aircraft engines. Thus, an understanding of vapour handling ability of small aircraft is essential to establish safe operating confines at existing fuel temperature and pressures.

Анализ процессов теплообмена в камерах сгорания авиационных поршневых двигателей с искровым зажиганием

Анализ процессов теплообмена в камерах сгорания авиационных поршневых двигателей с искровым зажиганием