scholarly journals The Operational Technique of Increasing Service Life Time of the Major Components of the Fighter Aircraft Engine Rotors

2021 ◽  
Vol 51 (3) ◽  
pp. 65-73
Author(s):  
Serhii Pashchenko ◽  
Artem Shulhin ◽  
Volodimyr Samuleev ◽  
Оleksandr Lobunko ◽  
Оleg Dobridenko
Keyword(s):  
Life Cycle ◽  
Cyclic Loading ◽  
Operating Time ◽  
Aircraft Engine ◽  
Individual Characteristics ◽  
Fighter Aircraft ◽  
Previous Operation ◽  
Operational Technique ◽  
Cyclic Damage ◽  
Engine Rotors

Abstract The operational technique for the major components of the fighter aircraft engine rotors has been introduced basing on the real conditions of their cyclic loading in each flight or ground test and a priori information on their previous operation. It has been confirmed that the obtained technical solutions not only conform to the current methods of accounting for the depletion of the life cycle of the Afterburning Turbofan Engine (ATE) but also introduce additional opportunities to consider individual characteristics and conditions of their cyclic loading throughout the overall operating time. A method for estimating the depletion of the life cycle in accordance with the Total Accumulated Cycle (TAC) has been proposed. It allows us to compare the actual operating time of the ATE in hours and the accumulated value of cyclic damage to the engine and its major components (within the TAC parameter) during the previous operation.

Predicting individual post-penitentiary crimes

2020 ◽  
pp. 80-88
Author(s):  
Валерий Ильич Терехин ◽  
Виктор Валентинович Чернышов ◽  
Ольга Викторовна Имамбаева
Keyword(s):  
Life Cycle ◽  
Individual Characteristics ◽  
Penal Institutions

Факторы рецидивных преступлений. Оценка вероятности рецидивов по стадиям жизненного цикла преступности. Проблема взаимосвязи факторов. Адаптация осужденных после освобождения. Классификация осужденных по вероятности постпенитенциарных рецидивов. Латентность преступлений как ограничение достоверности прогнозов преступности. Моделирование индивидуальных постпенитенциарных преступлений. В статье обоснована классификация осужденных на момент их освобождения из учреждений УИС по вероятности совершения ими постпенитенциарного рецидива. Приведен пример моделирования сроков совершения постпенитенциарных преступлений. В работе выделена совокупность индивидуальных характеристик осужденного, которые отражают его нацеленность на совершение латентных преступлений и способности их совершения. Factors of recidivism. Assessment of the probability of recidivism by stages of the life cycle of crime. The problem of interrelation of factors. Adaptation of prisoners after release. Classification of prisoners according to the likelihood of post-penitentiary relapse. Crime latency as a limitation on the reliability of crime forecasts. Modeling of individual post-penitentiary crimes. The article substantiates the classification of convicts at the time of their release from penal institutions by the probability of their post-penitentiary recidivism. An example of modeling the timing of post-penitentiary crimes is given. The paper highlights a set of individual characteristics of the convict, which reflect his focus on the Commission of latent crimes and the ability to commit them.

Integrated Training Solutions: An Effective Tool to Synchronize People and Maintenance (U.S. Navy LCAC Case Study)

2012 ◽  
Author(s):  
Maurice Hartey ◽  
Thomas Bodman ◽  
Arlene Korn
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Training Programs ◽  
Operating Time ◽  
Life Cycle Management ◽  
Cost Driver ◽  
Maintenance Costs ◽  
Knowledge And Skills ◽  
Long Run

Maintenance, especially in a Marine environment, is continuous and costly. Life Cycle Management of a Marine Gas Turbine system encompasses many costs, of which repair parts, labor and equipment downtime associated with failures and maintenance are a significant portion. In fact, people (labor) make up the largest component of overall maintenance costs. Investing in people the largest cost driver to life cycle cost has a direct return in the long run, in terms of maintenance effectiveness and efficiencies. Applying and reinforcing knowledge and skills in a maintenance environment translates to improved reliability outcomes, longer operating time, fewer parts needs, and ultimately costs savings. However, given today’s constrained fiscal environment, the value of spending money for training rather than buying more parts or applying more maintenance, may not appear obvious. Such thinking is short sighted, and ultimately leads to reduced reliability and increased maintenance in the long run. This paper will explore these areas, and recommend how training programs can be effective predictive, proactive and responsive.

Multilevel methods in the dynamics of aircraft engine rotors

1984 ◽  
Vol 20 (12) ◽  
pp. 1137-1141
Author(s):  
A. S. Vol'mir ◽  
V. F. Mikhnev ◽  
A. E. Tikhomirov ◽  
V. I. Khorkhordin
Keyword(s):  
Aircraft Engine ◽  
Multilevel Methods ◽  
Engine Rotors

The Development of Anomaly Distributions for Machined Holes in Aircraft Engine Rotors

2006 ◽  
Author(s):  
Richard Corran ◽  
Michael Gorelik ◽  
Darryl Lehmann ◽  
Stephane Mosset
Keyword(s):  
Risk Assessment ◽  
Relative Risk ◽  
Damage Tolerance ◽  
Probabilistic Approach ◽  
Aircraft Engine ◽  
Design Strategy ◽  
Assessment Methodology ◽  
Relative Risk Assessment ◽  
Risk Assessment Methodology ◽  
Engine Rotors

The Aerospace Industries Association (AIA) Rotor Integrity Sub-Committee (RISC) has proposed an enhanced damage tolerance design strategy for critical rotating parts intended to reduce the rate of uncontained rotor events. Building upon the industry committee’s experience in developing a probabilistic relative risk assessment methodology for hard alpha anomalies in titanium rotors, a similar probabilistic approach has been proposed for induced anomalies along machined hole surfaces in engine rotors. Key inputs to this strategy are the development of a surface anomaly distribution for machined holes and the benchmark of design target risk (DTR). The DTR is an FAA/industry agreed upon design target value of relative risk against which the results of the probabilistic risk assessment are compared.

scholarly journals The influence of stress level on the ratcheting magnitude and progress rate in steel alloys under uniaxial loading conditions

2021 ◽  
Author(s):  
Prasanth Chandrasekar
Keyword(s):  
Cyclic Loading ◽  
Plastic Strain ◽  
Strain Rate ◽  
Loading Condition ◽  
Stress Amplitude ◽  
Fatigue Loading ◽  
Mean Stress ◽  
Cyclic Loading Condition ◽  
Ratcheting Strain ◽  
Cyclic Damage

Engineering materials in their service life undergo symmetric or asymmetric fatigue loading, which leads to fatigue damage in the material. Ratcheting damage is due to the application of mean stress under cyclic loading condition. From deformation behavior perspective, application of mean stress under stress-controlled fatigue loading gives rise to accumulation of plastic strain in the material. Ratcheting strain increases with an increase in applied mean stress and stress amplitude. In addition, ratcheting behavior will increase in cyclic damage with the rise in strain accumulation and it can be illustrated by a shift in the hysteresis loop towards large plastic strain amplitudes. This study focuses on the ratcheting behavior of different steel materials under uniaxial cyclic loading condition and suggests a suitable method to arrest ratcheting by loading the materials at zero ratcheting strain rate condition with specified mean stress and stress amplitudes. The three dimensional surface is created with stress amplitude, mean stress and ratcheting strain rate for different steel materials. This represents a graphical surface zone to study the ratcheting strain rates for various mean stress and stress amplitude combinations.

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 EAGLE: An Interactive Engine/Airframe Life Cycle Cost Model

1982 ◽  
Author(s):  
E. J. Reed ◽  
R. R. Horton ◽  
J. B. Fyfe
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Development Process ◽  
Cost Model ◽  
Aircraft Engine ◽  
Preliminary Design ◽  
Weapon System ◽  
Technology Evaluation ◽  
Advance Technology ◽  
Design Decisions

A major portion of the Life Cycle Cost (LCC) of a modern high technology weapon system is determined by design decisions made very early in the development process. Many of these decisions are so fundamental that later changes become impractical. As a result, a usage-sensitive, interactive aircraft engine LCC model has been developed by Pratt & Whitney Aircraft to evaluate and prioritize potential technology candidates during conceptual/preliminary design. This paper discusses the development of the EAGLE (Engine/Airframe Generalized LCC Evaluator) model, its validation using results from the Advance Technology Engine Studies (ATES), and includes an example engine technology evaluation.

Actual vs Simulated Equipment for Aircraft Maintenance Training: Cost Implications of the Incremental vs the Unique Device

1979 ◽  
Vol 23 (1) ◽  
pp. 334-338
Author(s):  
Richard E. Vestewig ◽  
F. Thomas Eggemeier
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Test Equipment ◽  
Fighter Aircraft ◽  
Cost Estimates ◽  
Actual Equipment ◽  
Training Cost ◽  
Cost Implications ◽  
The Cost ◽  
Support Cost

Life cycle cost estimates were developed for use of simulated test equipment vs actual test equipment in a maintenance training program of the type used for current advanced fighter aircraft. Previous life cycle cost comparisons had not explicitly considered the cost implications of procurement and support of a unique training device vs an incremental device. This effort included the unique vs the incremental device factor. Total estimated fifteen year costs for simulated equipment trainers were significantly lower than comparable estimates for actual equipment trainers. The results indicate that the cost implications of a unique device vs an incremental device are important determinants of both acquisition and support cost estimates and should be considered fully in future life cycle costing efforts.

Life Cycle Analysis for a Powertrain in a Concept for Electric Power Generation in a Hybrid Electric Aircraft

2020 ◽  
Author(s):  
Michael Schneider ◽  
Jens Dickhoff ◽  
Karsten Kusterer ◽  
Wilfried Visser
Keyword(s):  
Life Cycle ◽  
Gas Turbine ◽  
Electric Propulsion ◽  
Aircraft Engine ◽  
Propulsion System ◽  
Civil Aviation ◽  
Propulsion Systems ◽  
Hybrid Propulsion ◽  
Hybrid Electric ◽  
The Impact

Abstract In the recent decades, civil aviation was growing 4.7% per annum. In order to reduce emissions promoting the global warming process, alternative propulsion systems are needed. Full-electric propulsion systems in aviation might have the potential for emission-free flights using renewable energy. However, several research efforts indicate electric propulsion only seems feasible for small aircraft. Especially due to the low energy density of batteries compared to fossil fuels. For this reason, hybrid propulsion systems came into focus, combining the benefits of all-electric and conventional propulsion system concepts. It is also considered as bridging technology, system test and basis for component development — and therewith paves the way towards CO2 free aviation. In the ‘HyFly’ project (supported by the German Luftfahrtforschungsprogramm LuFo V-3), the potential of a hybrid electric concept for a short/mid-range 19 PAX aircraft is assessed — not only on system but also on single component basis. In a recent study, the propulsion architecture and the operating mode of the gas turbine and the electric components have been defined [1]. In this paper, the advantages of the hybrid propulsion architecture and a qualitative assessment of component life are presented. Methods for life time prediction for the aircraft engine, the electric motor, the reluctance generator and the battery are discussed. The impact of turbine inlet temperature on life consumption is analyzed. The life cycle of the aircraft engine and the electric components including gradual component deterioration and consequent performance degradation is simulated by using an in-house gas turbine simulation tool (GTPsim). Therefore, various effects on electric propulsion system can be predicted for the entire drivetrain system in less than one hour.

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