scholarly journals A research stand for the testing of the sealing properties of the piston-rings-cylinder assembly in a combustion engine

2013 ◽  
Vol 153 (2) ◽  
pp. 54-62
Author(s):  
Grzegorz KOSZAŁKA ◽  
Jacek HUNICZ ◽  
Paweł KORDOS

The paper discusses research assumptions and describes a test stand for the investigations of the sealing properties of the piston rings. The research stand includes an engine brake together with a control system, a research engine and a lubrication and engine thermal state stabilization systems. The engine was fitted with a research piston containing a measuring device enabling the recording of fast varying quantities such as the pressures in the space between the rings, axial displacements of the oil sealing rings in the piston grooves and the temperatures of the gas blown through the seal.

The issues of cooling control automation for an internal combustion engine (ICE) of cars and trucks are considered. An algorithm for controlling the number of revolutions of the electric motors for the liquid pump and the radiator fan, depending on the temperature of the internal combustion engine coolant is proposed. This algorithm is stir up by the Arduino MEGA 2500 microcontroller in conjunction with the motor driver. The automatic control system for the thermal state of the internal combustion engine will reduce fuel consumption, wear of the cylinderpiston group, as well as the emission of harmful substances into the atmosphere.


2008 ◽  
Vol 133 (2) ◽  
pp. 44-53
Author(s):  
Dariusz SZPICA

The paper presents the issues related to the unevenness of air filling inside a cylinder of a combus-tion engine. In order to evaluate such an unevenness a test stand and simulation models have been built. The tests stand allows a full assessment of the influence of selected parameters on the uneven-ness of the filling process. In this case the deviations in individual ducts of an intake manifold have been analyzed. This variant has been repeated in simulation tests, where concentrated models have been used for the description of the phenomena. The tests have shown an approximately 6% influence of a 64oC temperature deviation on the unevenness of the cylinder filling. The simulation tests have not shown a significant impact of the thermal state on the filling process


Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.


2018 ◽  
Author(s):  
Sizwe Makhunga ◽  
Tivani P. Mashamba-Thompson ◽  
Mbuzeleni Hlongwa ◽  
Khumbulani W. Hlongwana

Author(s):  
Neng Wan ◽  
Guangping Zeng ◽  
Chunguang Zhang ◽  
Dingqi Pan ◽  
Songtao Cai

This paper deals with a new state-constrained control (SCC) system of vehicle, which includes a multi-layer controller, in order to ensure the vehicle’s lateral stability and steering performance under complex environment. In this system, a new constraint control strategy with input and state constraints is applied to calculate the steady-state yaw moment. It ensures the vehicle lateral stability by tracking the desired yaw rate value and limiting the allowable range of the side slip. Through the linkage of the three-layer controller, the tire load is optimized and achieve minimal vehicle velocity reduction. The seven-degree-of-freedom (7-DOF) simulation model was established and simulated in MATLAB to evaluate the effect of the proposed controller. Through the analysis of the simulation results, compared with the traditional ESC and integrated control, it not only solves the problem of obvious velocity reduction, but also solves the problem of high cost and high hardware requirements in integrated control. The simulation results show that designed control system has better performance of path tracking and driving state, which is closer to the desired value. Through hardware-in-the-loop (HIL) practical experiments in two typical driving conditions, the effectiveness of the above proposed control system is further verified, which can improve the lateral stability and maneuverability of the vehicle.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Shiqiang Wang ◽  
Jianchun Xing ◽  
Ziyan Jiang ◽  
Juelong Li

A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC) system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.


2015 ◽  
Vol 738-739 ◽  
pp. 935-940 ◽  
Author(s):  
Zhen Li ◽  
Pei Xu ◽  
Yu Ping Ouyang ◽  
Shi Lei Lv ◽  
Qiu Fang Dai

In order to reduce operation risk and working intensity in mountainous orchard transportation and to realize optimized control for the mountainous orchard electric-drive monorail transportation system, a mountainous orchard electric-drive monorail transporter control system was designed and developed in this study. The system mainly consists of modules as: manual and remote control, positioning, obstacle avoidance, speed measurement, motor control, electric-magnetic break, and the position limit. The driving speed, current consumption, break control, and battery pack running ability experiments were conducted to test the control system. Results indicated that, the transporter’s driving speed is 0.60~0.58 m/s when it is running on the ground with the load weight from 0 to 100kg. This speed is little affected by the load weight. The transporter’s driving speed is 0.45~0.28 m/s when it is climbing a steep hill with an angle of 39°. That speed is critically affected by the load weight. In further improvements, a shift mechanism will be introduced so that adjustable gear ratio could be achieved thus solve the current overload problem in a full load situation.


Aviation ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 130-135
Author(s):  
Vaidotas Kondroška ◽  
Jonas Stankūnas

This work reviews the innovative and progressive methods of determination and analysis of safety objectives using Vilnius A-SMGCS example. The aim of the analysis is to determine how failures in this system could affect flight safety in Vilnius aerodrome. Identified safety objectives will limit the frequency of occurrence of hazards enough for the associated risk to be acceptable, and will ensure that appropriate mitigation means are reflected subsequently as Safety Requirements for the system. Analysis reflects aspects of A-SMGCS Safety objectives, which should be taken into consideration. Santrauka Darbe apžvelgiami progresyvūs saugos tikslų analizės metodai pagal Vilniaus aerodromo automatizuotos antžeminio eismo stebėjimo ir kontrolės sistemos veiklos pavyzdį. Analizuojama, kaip šios sistemos sutrikimai gali paveikti skrydžių saugą Vilniaus aerodrome. Remiantis galimų pavojų skrydžių saugai analize, tyrime nustatyti saugos tikslai, pagal kuriuos vėliau bus numatomos riziką mažinančios priemonės (galimų pavojų neutralizavimui ar kylančios rizikos sumažinimui iki priimtino lygio). Straipsnyje pateikiami veiksniai, kuriuos reikėtų įvertinti nustatant aerodromo automatizuotos antžeminio eismo stebėjimo ir kontrolės sistemos saugos tikslus.


Author(s):  
Claudia ARAUJO MACEDO ◽  
Jos MENTING

Cybersecurity in industrial control system environments has become a significant concern and is even more relevant in the context of critical infrastructures where control system disruption could have a profound impact on health, safety and the environment. This makes this type of system a major target for malicious activities. Notwithstanding an organization’s interest in protecting its industrial control systems against cyber-attacks, the implementation of security measures, whether technical, organizational or human, still faces resistance and is often seen as a constraint. Using the best technology to protect industrial control systems makes no sense if persons with access do not act attentively and protectively. Technical and human cybersecurity measures are intrinsically linked, and it is essential that all persons with access to these systems are fully aware of the inherent cyber risks. Organizations must also act so that staff receive appropriate training on how to keep systems continuously protected against cyber-attack when carrying out their daily tasks. These educational processes can contribute to building an effective cybersecurity culture fully reflective of management and staff attitudes, so that the availability, integrity and confidentiality of information in industrial control systems can be assured.


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