Modelling of the Military Helicopter Operation Process in Terms of Readiness

Ziółkowski, Jarosław; Małachowski, Jerzy; Oszczypała, Mateusz; Szkutnik-Rogoż, Joanna; Lęgas, Aleksandra

doi:10.14429/dsj.71.16422

Cited by 12 publications

(8 citation statements)

References 32 publications

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“…In operation, the most frequently used models are based on discrete processes in states, developed for both discrete and continuous time [8,16,24,28,29].…”

Section: Methodsmentioning

confidence: 99%

“…Military exploitation systems are largely based on a plan-preventive maintenance strategy, aiming to maximize the technical availability of facilities [6][7][8][9]. This strategy assumes the implementation of maintenance with a specific labor intensity, in accordance with the required scope.…”

Section: Introductionmentioning

confidence: 99%

“…Markov models with 9-and 16-state phase spaces are presented in [8,30] with much more elaborate models. The increased number of states allows a detailed analysis of the process and factors affecting the technical readiness of the facility.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of Light Utility Vehicle Readiness in Military Transportation Systems Using Markov and Semi-Markov Processes

2022

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This paper presents the issues of modeling the operation process of light utility vehicles operating in military transport systems. The required condition for the effective operation of the system is to maintain the means of transport at the appropriate level of technical readiness. For this purpose, it is necessary to equip the technical system with appropriate resources enabling the efficient implementation of fuel refilling, maintenance and repair processes. Each failure of the means of transport causes a significant reduction in transport capacity, which then results in the inability to perform the planned tasks. Quality control and vehicle operation process management require advanced mathematical methods and tools. Three indicators have been proposed as quantitative characteristics for assessing and optimizing the availability of military vehicles: functional readiness, technical efficiency and airworthiness. To determine their value, a stochastic exploitation model was developed based on the application of the theory of Markov processes. Based on the collected empirical data, a nine-state phase space of the studied process was identified. Operating states were distinguished relating to the implementation of the transport task, refueling, parking in the garage, as well as maintenance and repairs. As part of the considerations for the continuous time, verification of the distributions of time characteristics led to the development of a semi-Markov model. The ergodic probabilities calculated based on the conditional probability matrix of interstate transitions and the expected values of the time spent in the states were used to determine the indicators of functional availability, efficiency and technical suitability. In order to determine the possibility of optimizing the process, a sensitivity analysis was performed. Reducing the amount of time the vehicles must wait for repair by about 50% can improve the values of the indexes from 0.91 to 0.95.

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“…In operation, the most frequently used models are based on discrete processes in states, developed for both discrete and continuous time [8,16,24,28,29].…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Analysis of Light Utility Vehicle Readiness in Military Transportation Systems Using Markov and Semi-Markov Processes

2022

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“…Hence the need to replace the filter element when a certain pressure drop p fdop is reached. The operation of an air filter is a technical compromise between pressure drop (car mileage), separation efficiency and accuracy, and engine wear and durability, as well as facility reliability [45,46].…”

Section: Introductionmentioning

confidence: 99%

Empirical study of the effect of the air filter on the performance and exhaust emissions of a diesel engine

Dziubak¹,

Karczewski²,

Dziobek³

2023

Combustion Engines

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The results of an experimental study of the effect of the pressure drop of the air filter pf on the operat-ing parameters and exhaust emissions of a modern CI internal combustion engine of a truck equipped with an electronically controlled power system are presented. The tests were carried out for an air filter with a clean filter cartridge Δpf0 = 0,58 kPa and with a cartridge contaminated after a service mileage (about 50 thousand km) ΔpfD = 2,024 kPa. In each test, engine performance, exhaust emissions and relative change in emissions were determined: CO, NOx, HC, CO2, H2O. It was found that an increase in the filter resistance pf causes a decrease in the filling degree by 12%, engine useful power by almost 10%, exhaust gas temperature by a maximum of 30oC and an increase in specific fuel consumption by almost 5%. Air filter resistance has no significant effect on NOx emissions and HC concentration. There is a reduction in H2O emissions by up to 7%, CO by up to 13% and CO2 by up to 4%, and an increase in oxygen emissions by 15%, depending on operating conditions.

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“…The operation of an air filter is a technical compromise between the ever-increasing pressure drop that is the cause of decreased power, increased fuel consumption and increased exhaust emissions of a vehicle engine and the high efficiency and accuracy of inlet air filtration, factors that determine the value of component wear, durability and reliability of the engine and the entire facility [ 29 , 30 ]. Hence, there are constant efforts of researchers to obtain an air filtration element with a low pressure drop, in order to reduce the adverse effects of the air filtration element on engine performance.…”

Section: Introductionmentioning

confidence: 99%

Experimental Studies of PowerCore Filters and Pleated Filter Baffles

Dziubak

2022

Materials

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The material most commonly used to filter and clean the intake air of vehicle internal combustion engines is pleated filter paper, which in most cases is shaped in the form of a cylinder or panel. The production technology has a low cost and is not complicated. In addition to high separation efficiency and filtration performance, pleated filter media are required to have low initial pressure drop, which depends on the geometry of the bed. Much research has been conducted in this area. Dust accumulated in the filter bed causes an increase in pressure drop, which is the cause of deformation and sticking of pleats. The lack of stability of the pleats, the need to strengthen them, and the need to obtain small sizes while achieving high efficiency and accuracy of filtration of engine intake air was the reason for the development of a different design and a new technology for making filter cartridges called PowerCore. The distinctive feature of these filters is axial flow in one direction of the air stream, which avoids turbulence and thus minimizes pressure drop. This paper presents a comparative analysis of a standard PowerCore and PowerCore G2 filter bed and two cylindrical filters with a pleated filter bed made of cellulose and polyester. The conditions and methodology of experimental testing of filters with test dust are presented. During the tests, the characteristics of separation efficiency and filtration performance, as well as pressure drop as a function of the mass of dust retained on the filter of two PowerCore filters and two cylindrical filters were performed. Three specimens of test filters with the same filtration area were made from each sample of filter bed. The results showed that in each test of the filter bed, there is an initial filtration period characterized by low (96–98%) initial separation efficiency and the presence of large (dpmax) dust grains. As the dust loading of the bed increases, the separation efficiency and filtration performance obtain higher and higher values. The initial period of filtration ends when the conventional value (99.9%) of separation efficiency is reached. The duration of this period depends on the type of filter bed and for the PowerCore G2 filter ends for a dust loading of km = 33.1 g/m2, and for the cellulose filter for km = 117.3 g/m2. During the initial period, the air behind the PowerCore G2 filter contains grains with sizes in the range of dpmax = 9–16 µm. Behind the cellulose filter, dust grains are much larger, dpmax = 17–35 µm. The total operating time of the PowerCore G2 filter, limited by the achievement of the permittivity resistance Δpwdop = 3 kPa, is twice that of the other filter compositions tested.

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Modelling of the Military Helicopter Operation Process in Terms of Readiness

Cited by 12 publications

References 32 publications

Analysis of Light Utility Vehicle Readiness in Military Transportation Systems Using Markov and Semi-Markov Processes

Analysis of Light Utility Vehicle Readiness in Military Transportation Systems Using Markov and Semi-Markov Processes

Empirical study of the effect of the air filter on the performance and exhaust emissions of a diesel engine

Experimental Studies of PowerCore Filters and Pleated Filter Baffles

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