scholarly journals Problems of aviation leaded gasoline application on aircraft

2020 ◽  
Vol 23 (3) ◽  
pp. 8-16
Author(s):  
K. I. Gryadunov ◽  
A. N. Timoshenko ◽  
E. U. Starkov
Keyword(s):  
Aircraft Engine ◽  
Combustion Products ◽  
Point Of View ◽  
Operating Conditions ◽  
Stable Operation ◽  
Negative Consequences ◽  
Aviation Gasoline ◽  
Liquid Form ◽  
Engine Operation ◽  
Multi Stage

A steady trend of expanding the small aircraft fleet equipped with piston engines is observed today. Special fuel (aviation gasoline with specified operational properties) for aircraft piston engines (PE) ensuring their stable operation in all modes and under all operating conditions is used. The indicators of aviation fuels operational properties including gasoline are achieved by means of adding special additives. One of these additives is an anti-knock additive – tetraethyl lead (TEL) that is added into the fuel in a certain amount in an ethyl liquid form. Despite the excellent TEL properties as an anti-knock additive, it also has a number of significant disadvantages. From the point of view of aircraft engine operation, it is noted that the TEL combustion products (decomposition) that are not effectively removed from the combustion chamber, enter the oil system in a significant amount, causing fine oil filters clogging. The article notes that even a small content of TEL decomposition products in aviation oils deteriorates dramatically their pumping capacity and leads to complete fine oil filters clogging for few minutes of engine operation, even on fresh oil. Moreover, the multi-stage oil cleaning stipulated by the design of some PE does not have a significant impact on this negative factor posing a threat to flight safety. These days the lead-containing gasoline use for aviation PE has no alternative, so solutions to reduce the negative consequences while applying are required.

scholarly journals EXPERT STUDIES OF VIOLATIONS OF THE OPERATING CONDITIONS OF AUTOMOBILE ENGINES WHEN USING THEM IN AVIATION

2021 ◽  
pp. 53-59
Author(s):  
Alexander Khrulev ◽  
Iryna Saraievа
Keyword(s):  
Operating Time ◽  
Aircraft Engine ◽  
Point Of View ◽  
Operating Conditions ◽  
General Aviation ◽  
Aircraft Engines ◽  
Automobile Engine ◽  
Design Changes ◽  
Automobile Engines ◽  
Single Use

Problem. The features of the design and operation of piston engines in general aviation are considered. Comparative analysis of design features and parameters of automobile and aircraft engines is carried out. It is shown that car engines, despite the high technical level achieved at the beginning of the 21st century, do not technically meet aviation requirements. At the same time, engines created on the basis of automobiles through their deep modernization meet aviation requirements, however, modernization and adaptation of a standard automobile engine to aviation use in terms of costs compared to the creation of a new engine. Purpose. Carry out research on the failure of automobile engines used in light aviation. Methodology. Rough calculations of the service life of an automobile engine were made based on standard driving tests and a flight plan. According to the results of calculations, it has been established that the resource of a standard automobile engine in aviation is reduced many times due to prolonged operation at high loads and rotational speed that are not characteristic of ordinary automotive applications. Results. Experimental data have been obtained on the actual failure of standard automobile engines in aviation during the operating time, significantly less resource of aircraft engines of well-known brands. Based on the results of the study, it was concluded that the use of general aviation automobile engines is economically ineffective due to a short resource and insufficient reliability. Originality. Modern automobile engines, despite their technical perfection, cannot be used in aviation, since they do not correspond to aviation operating conditions. At the same time, adaptation of automobile engines to aviation applications is possible, but requires significant design changes, which makes their single use, as a rule, technically impractical and economically ineffective. Practical value. Due to the fact that saving on an aircraft engine is unacceptable from the point of view of flight safety, the aviation use of automobile engines without special modernization carries excessive risks of failures and their consequences. As a result, serial aircraft engines Lycoming, Continental, Jabiru, ULPower, Rotax, Limbach and others have virtually no alternative in general aviation.

scholarly journals Application of a Constant Gain Extended Kalman Filter for In-Flight Estimation of Aircraft Engine Performance Parameters

2005 ◽  
Author(s):  
Takahisa Kobayashi ◽  
Donald L. Simon ◽  
Jonathan S. Litt
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Accurate Estimation ◽  
Aircraft Engines ◽  
Performance Parameters ◽  
Efficient Manner ◽  
Engine Operation ◽  
Engine Model

An approach based on the Constant Gain Extended Kalman Filter (CGEKF) technique is investigated for the in-flight estimation of non-measurable performance parameters of aircraft engines. Performance parameters, such as thrust and stall margins, provide crucial information for operating an aircraft engine in a safe and efficient manner, but they can not be directly measured during flight. A technique to accurately estimate these parameters is, therefore, essential for further enhancement of engine operation. In this paper, a CGEKF is developed by combining an on-board engine model and a single Kalman gain matrix. In order to make the on-board engine model adaptive to the real engine’s performance variations due to degradation or anomalies, the CGEKF is designed with the ability to adjust its performance through the adjustment of artificial parameters called “tuning parameters.” With this design approach, the CGEKF can maintain accurate estimation performance when it is applied to aircraft engines at off-nominal conditions. The performance of the CGEKF is evaluated in a simulation environment using numerous component degradation and fault scenarios at multiple operating conditions.

A Model for System Instability Analysis in a Multi-Stage Intercooled Industrial Compressor

2019 ◽  
Author(s):  
Jiaye Gan ◽  
Ahmed Abdelwahab ◽  
Viktor Kilchyk
Keyword(s):  
Guide Vane ◽  
Transient Behavior ◽  
Industrial Applications ◽  
Operating Conditions ◽  
System Response ◽  
Stable Operation ◽  
System Behavior ◽  
Multi Stage ◽  
Performance Reduction ◽  
Inlet Conditions

Abstract Compression equipment used for industrial applications are typically comprised of multi-stage intercooled compressor stages. The presence of large volume intercoolers between individual stages adds a layer of complexity currently not present in publicly available surge models both in terms of system behavior and recovery analysis. In this work a compressible, temporal, and spatial model is developed in which the conservation equations are solved numerically for each of the system components, i.e. pipes, plenums and heat exchangers, valves, and individual compressor stages. The model can identify the onset of instability on an individual stage basis as well as the switching that can occur between the controlling stages of the instability onset when the operating conditions change, e.g. changes in inlet conditions, intercooler fouling or cooling tower performance reduction, and speed or guide vane changes. The model is therefore used both as a stage stacking model during the compressor stable operation as well as a model of the transient behavior of the system past the stable operation. An inertial model of the compressor drive train is also incorporated to analyze the effects of power transients, e.g. emergency shut down (ESD), on the system behavior. In this article details of the developed model are provided. Several test cases are presented. The model is then used to demonstrate the proper sizing of a vent valve of a base load compressor to meet the required system response specification in a surge event. The developed model represents an improvement over available transient system models in terms of predicting the post stable behavior of multi-stage intercooled compressors.

scholarly journals Efficiency of using inverter power plants as part of multifunctional energy technology complexes

2020 ◽  
Vol 21 (4) ◽  
pp. 244-253
Author(s):  
Ivan Ya. Redko ◽  
Andrey A. Malozemov ◽  
Georgiy A. Malozemov ◽  
Alexey V. Naumov ◽  
Dmitry V. Kozminykh
Keyword(s):  
Power Plant ◽  
Fuel Consumption ◽  
Damage Accumulation ◽  
Power Plants ◽  
Fuel Efficiency ◽  
Point Of View ◽  
Operating Conditions ◽  
Simultaneous Increase ◽  
Boost Pressure ◽  
Engine Operation

A method has been developed for a comprehensive multi-criteria assessment of the efficiency of using inverter power plants as part of multifunctional energy-technological complexes with technical solutions aimed at reducing the negative consequences of the internal combustion engine operation with an optimal from the point of view of fuel efficiency speed. The method includes: synthesis of the optimal engine speed control algorithm, determination of the complex operating modes under operating conditions, assessment of changes in fuel consumption and harmful substances emissions with exhaust gases and resource consumption rate when the engine is switched to the operating mode with the optimal speed, complex technical and economic assessment of the inverter power plants efficiency. On the example of an inverter power plant with a capacity of 100 kW, the need to apply the method is proved. It was found that the engine operation with the optimal from the point of view of fuel efficiency speed and without additional design measures entails an increase in the damage accumulation rate by 1.7-2.1 times and therefore is economically inexpedient, despite a decrease in fuel consumption by 1% or more. It was found that a decrease in the compression ratio with a simultaneous increase in the boost pressure makes it possible to increase the engine resource up to a functional failure due to damage accumulation by 43% and to a parametric failure due to wear by 32%, while the operating costs of the inverter power plant will decrease by 3.7% relative to the base (no changes) power plants. The emission of soot particles will decrease by about 2 times, nitrogen oxides - by 2%, hydrocarbons - almost to zero.

Probabilistic Engine Performance Scatter and Deterioration Modeling

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Stefan Spieler ◽  
Stephan Staudacher ◽  
Roland Fiola ◽  
Peter Sahm ◽  
Matthias Weißschuh
Keyword(s):  
Test Data ◽  
Probabilistic Approach ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Data ◽  
Maintenance Cost ◽  
Performance Parameters ◽  
Engine Operation ◽  
The Impact

The change of performance parameters over time due to engine deterioration and production scatter plays an important role to ensure safe and economical engine operation. A tool has been developed which is able to model production scatter and engine deterioration on the basis of elementary changes of numerous construction features. In order to consider the characteristics of an engine fleet as well as random environmental influences, a probabilistic approach using Monte Carlo simulation (MCS) was chosen. To quantify the impact of feature deviations on performance relevant metrics, nonlinear sensitivity functions are used to obtain scalars and offsets on turbomachinery maps, which reflect module behavior during operation. Probability density functions (PDFs) of user-defined performance parameters of an engine fleet are then calculated by performing a MCS in a performance synthesis program. For the validation of the developed methodology pass-off test data, endurance engine test data, as well as data from engine maintenance, incoming tests have been used. For this purpose, measured engine fleet performance data have been corrected by statistically eliminating the influence of measuring errors. The validation process showed the model’s ability to predict more than 90% of the measured performance variance. Furthermore, predicted performance trends correspond well to performance data from engines in operation. Two model enhancements are presented, the first of which is intended for maintenance cost prediction. It is able to generate PDFs of failure times for different features. The second enhancement correlates feature change and operating conditions and thus connects airline operation and maintenance costs. Subsequently, it is shown that the model developed is a powerful tool to assist in aircraft engine design and production processes, thanks to its ability to identify and quantitatively assess main drivers for performance variance and trends.

Probabilistic Engine Performance Scatter and Deterioration Modeling

2007 ◽  
Author(s):  
Stefan Spieler ◽  
Stephan Staudacher ◽  
Roland Fiola ◽  
Peter Sahm ◽  
Matthias Weißschuh
Keyword(s):  
Test Data ◽  
Probabilistic Approach ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Data ◽  
Maintenance Cost ◽  
Performance Parameters ◽  
Engine Operation ◽  
The Impact

The change of performance parameters over time due to engine deterioration and production scatter plays an important role to ensure safe and economical engine operation. A tool has been developed which is able to model production scatter and engine deterioration on the basis of elementary changes of numerous construction features. In order to consider the characteristics of an engine fleet as well as random environmental influences, a probabilistic approach using Monte Carlo Simulation (MCS) was chosen. To quantify the impact of feature deviations on performance relevant metrics, non-linear sensitivity functions are used to obtain scalars and offsets on turbomachinery maps which reflect module behavior during operation. Probability density functions (PDFs) of user-defined performance parameters of an engine fleet are then calculated by performing an MCS in a performance synthesis program. For the validation of the developed methodology pass-off test data, endurance engine test data, as well as data from engine maintenance incoming tests have been used. For this purpose, measured engine fleet performance data have been corrected by statistically eliminating the influence of measuring errors. The validation process showed the model’s ability to predict more than 90% of the measured performance variance. Furthermore, predicted performance trends correspond well to performance data from engines in operation. Two model enhancements are presented, the first of which is intended for maintenance cost prediction. It is able to generate PDFs of failure times for different features. The second enhancement correlates feature change and operating conditions and thus connects airline operation and maintenance costs. Subsequently, it is shown that the model developed is a powerful tool to assist in aircraft engine design and production processes thanks to its ability to identify and quantitatively assess main drivers for performance variance and trends.

Financial Risks of the Bank: Assessment and Mechanism of Neutralization

2020 ◽  
Vol 22 (1) ◽  
pp. 6-12
Author(s):  
Nelia Volkova ◽  
◽  
Alina Mukhina ◽  
Keyword(s):  
Risk Assessment ◽  
Financial Stability ◽  
Financial Risk ◽  
Stable Operation ◽  
Financial Risks ◽  
Negative Consequences ◽  
Conceptual Approach ◽  
Relevant Today ◽  
Banking Institution ◽  
The Impact

Abstract. Introduction. The issue of financial risk management of commercial banks is quite relevant today, because the activity of banks is the most risky of all. The presence of risks in banking can lead to unexpected losses, namely the loss of own resources. That’s why for the stable operation of the bank without loss the priority is to assess the financial risks, which is the basis for their further neutralization. Purpose. The purpose of the article is to develop conceptual provisions for assessment financial risks and justifying the need to neutralize them. Results. The article analyzes the impact of risks on the financial stability of a banking institution. The main methods of bank risk assessment are considered. All these include the statistical method, the analytical method, the expert method, the analogue method and the combined method. The necessity of neutralization of financial risks in order to avoid negative consequences is substantiated. Also the methods of bank risks neutralization are considered. It should be noted that these methods of neutralization can not only be used, but also supplement the list with new methods must be done, which in the future will protect the bank from the influence of undesirable factors. A conceptual approach to the assessment and neutralization of financial risks is proposed. This conceptual approach aims to ensure effective assessment of the level of risk with their subsequent neutralization Conclusions. Use of a conceptual approach will allow an effective risk assessment and decision-making to avoid or accept risk. Thanks to using this approach, the banking institution will be able to react swiftly to the presence of financial risks and to prevent the occurrence of negative consequences, which may lead to a violation of the financial stability of the bank.

Tertiary Nitrification Pilot Plants on Parisian Waste Water

1990 ◽  
Vol 22 (1-2) ◽  
pp. 347-352 ◽  
Author(s):  
C. Paffoni ◽  
B. Védry ◽  
M. Gousailles
Keyword(s):  
Waste Water ◽  
Metropolitan Area ◽  
Fixed Bed ◽  
Point Of View ◽  
Operating Conditions ◽  
Research Center ◽  
Daily Output ◽  
Practical Point ◽  
Fixed Bed Reactors

The Paris Metropolitan area, which contains over eight million inhabitants, has a daily output of about 3 M cu.meters of wastewater, the purification of which is achieved by SIAAP (Paris Metropolitan Area Sewage Service) in both Achères and Valenton plants. The carbon pollution is eliminated from over 2 M cu.m/day at Achères. In order to improve the quality of output water, its tertiary nitrification in fixed-bed reactors has been contemplated. The BIOFOR (Degremont) and BIOCARBONE (OTV) processes could be tested in semi-industrial pilot reactors at the CRITER research center of SIAAP. At a reference temperature of 13°C, the removed load is approximately 0.5 kg N NH4/m3.day. From a practical point of view, it may be asserted that in such operating conditions as should be at the Achères plant, one cubic meter of filter can handle the tertiary nitification of one cubic meter of purified water per hour at an effluent temperature of 13°C.

scholarly journals Optimal Tuner Selection for Kalman Filter-Based Aircraft Engine Performance Estimation

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Donald L. Simon ◽  
Sanjay Garg
Keyword(s):  
Kalman Filter ◽  
Estimation Error ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Experimental Simulation ◽  
Tuning Parameter ◽  
Estimation Accuracy ◽  
On Line

A linear point design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multivariable iterative search routine that seeks to minimize the theoretical mean-squared estimation error. This paper derives theoretical Kalman filter estimation error bias and variance values at steady-state operating conditions, and presents the tuner selection routine applied to minimize these values. Results from the application of the technique to an aircraft engine simulation are presented and compared with the conventional approach of tuner selection. Experimental simulation results are found to be in agreement with theoretical predictions. The new methodology is shown to yield a significant improvement in on-line engine performance estimation accuracy.

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