The article is devoted to the problem of decision support in a simulation environment prepared for the air traffic control service. The limitations resulting from the functionality of the airport have been presented. In addition, the “integration” problems resulting from the movement of aircraft on the apron have been presented. The article outlines optimization problems such as minimizing the total taxiing time, taking into account the waiting time for the start of the runway, minimizing the time elapsed from the first taxiing to the end of taxiing by the last aircraft or multi-faceted functions, including, for example, penalties for deviations from the schedule of take-off / landing operations, failure to keep the CFMU time slots, or for too long taxiing cycles. The article presents restrictions on taxiing of aircraft, integration with other airport operations, decision problems and applied algorithms, groups of restrictions on taxiing of aircraft, scheduled flight table, dependencies between individual operations, positioning of aircraft.
In dynamic tests, especially landing gears, it is necessary to measure and record load levels. In this article, authors present measurement methods used in the landing gear tests on the 10-Ton Drop Test Machine, which is capable of simulating conditions similar to real landing in landing energy dissipation tests. Possible test objects include dampers, shock absorbers, and crash structures and devices. In described case load measurement can be done by several methods where one of them is strain-gauge plate based load measurement. This type of measurement is weighting system under the test object where all forces acting on it are measured. Strain gauge plate is usually tailor-made measurement system, which is composed out of mechanical device (plate itself) equipped with strain gauge force sensors, strain gauge amplification system and recording system. In addition, differences between static and dynamic measurements are described as well as influence of dynamic test conditions on strain gauges behaviour. In the article, authors describe general layout of the system, advantages and disadvantages of the test stand and problems that may appear during measuring. Authors also emphasize how the accuracy of the design affects to the quality of measurement. At the end of the article, advantages and disadvantages of the test stand and problems that may appear during measuring are described.
In the article, legal norms regarding the reduction of sulphur content limits in exhaust gases in special areas were presented. Then an overview of various solutions for supplying the marine engine with heavy fuel, distillation fuel and gas was made. In addition, the problem of using low-sulphur fuels in internal combustion engines was described. The presented solutions are a response to the latest provisions being part of the VI Annex of the MARPOL Convention, which entered into force on 01.01.2015. These provisions constitute that sulphation of fuel used in Emission Control Areas (ECAs) may not exceed 0.1%. Then, to meet the requirements, the conditions of using heavy fuels for supplying diesel engines were presented. Individual solutions such as the use of low-sulphur fuels, exhaust gas scrubber assembly, and the supply of liquefied natural gas (LNG) from the technical side were shown. Besides, the advantages and disadvantages of each of them were also indicated. In the following part, the economic analysis of the selected ship was made. Its purpose was to evaluate economically in the assumed time of operation, and then select the optimal solution for a given unit. For the comparative analysis, the use of low-sulphur fuels was used; the assembly of the scrubber, as well as the adaptation of the unit to use liquefied natural gas (LPG). The article was finished with conclusions; the most important of them is that the use of fuels with reduced sulphur content is the most expensive solution for the selected ship. The cost of the remaining solutions is at a comparable level, but they require greater interference in the ship’s construction.
Marianna Jacyna, Jacek Kukulski, Piotr Gołębiowski, Sławomir Jasiński and Wawrzyniec Wychowański
Railway transport is considered the most environmentally friendly. However, taking into account all factors, (including point pollution associated with the production of energy necessary for the movement of electric traction vehicles); this position is attractive, but a little less. Therefore, it is necessary to ensure that the amount of energy produced for railway transport is sufficient, but the lowest as possible. Creating new systems whose components for correct operation require a supply of electricity, they should be designed in such a way as to consume as little energy but meeting a series of standards. The aim of the article is to review selected requirements for the power supply of a railway vehicle equipped with automatic train control devices and identification of energy demand in the scope of supplying the rmCBTC on-board system, which is being developed by Rail-Mil Computers Company from Warsaw and the Faculty of Transport of the Warsaw University of Technology. The article presents an analysis of formal and legal requirements in the field of traction vehicles. Reference was made to the list of the Office of Rail Transport and the standards not included in it − PN-EN 50155, PN-EN 61000-6 and PN-EN 50125-2. Energy requirements in the field of traction vehicles equipped with an automatic train control system have been identified − e.g. voltage range of the onboard system, permissible decays, voltage dips, disturbances and environmental requirements. The energy requirements for the rmCBTC on-board system were also identified.
The purpose of this article was to show two thing thermal issues theory and thermovision tests in the laboratory. The main idea of this article was to describe the thermal issues theory of interesting problem base on the thermovision tests of new type electric brake prototype. After the creation of new product the designer needed to know how behave the prototype of the brake during tests with higher energy which could increase the temperatures on the object in our case of the electric brake prototype. The first step in that kind of issues was thermal analysis, which is very useful to define and subscribe the thermal issues. The second step it was measurement of the temperature, which was really significant during the electric brake tests. It was really important to check the temperature of engines. If there was some influence to the brake during braking. One of the method was using special thermal camera. The camera was checking the temperature during whole test after beginning the test to the end of the trial. The full spectrum of the temperature allowed the author to verify if there was some influence of temperature to the new electric brake prototype. The thermocouple was other type of sensors, which was normally used in our laboratory methodology to check temperature during the test. The pyrometer was other type of the method, which was used to measure the temperature after the test. The results of this measurement were subscribed in this article.
Magdalena Szwaja, Paweł Mazuro and Stanisław Szwaja
The main aim of the research was to investigate influence of overlap of the natural gas fuelled spark ignited engine on the following parameters: Indicated Mean Effective Pressure (IMEP), heat rate release including combustion phases (ignition lag, main combustion phase). The content of the study includes results from processing in-cylinder pressure measurements, heat release rate analysis, combustion phases, and finally the conclusions. The tests were carried out on the test bed including the single cylinder research engine with a displacement volume of 550 cm3. The engine was equipped with independent cam phasors for both intake and exhaust valves, but for this investigation, the exhaust valve timing was fixed (the exhaust cam centre line was fixed at -95 crank angle (CA) deg before Top Dead Centre) and intake valve timing was changed (the intake cam centre line was varied from 90 to 150 CA deg after Top Dead Centre). The overlap was changed in the range from 85 to 25 CA deg. 8 tests series were performed, each singular series consisted of 300 consecutive engine combustion cycles. As observed, by varying the valve overlap it contributes to significant change in the peak combustion pressure, peak of heat release rate, and combustion phases. Summing up, variable valve timing affects compression and expansion strokes by changing polytropic indexes due to various amounts of exhaust residuals trapped in the cylinder. It affects not only engine volumetric efficiency but also the heat release rate and IMEP, so it does engine performance. Thus, variable valve timing can be considered as valuable tool that can be applied to the natural gas fuelled internal combustion engine.
Remarkable characteristics of high temperature thermoplastic (HTP) matrix used in composite materials reinforced with continuous fibres causes growing application in composite industry. Because of high processing temperature of some semi, crystalline matrix there is limited number of technologies that can be used for part manufacturing. Press forming is an example of technology that allows manufacturing high quality complex parts made of HTP reinforced fibres composite. In order to manufacture part with acceptable quality and mechanical properties, uniform pressure distribution during the process is required.
In this article, tooling design process focused on uniform pressure distribution for manufacturing of supporting rib was presented. In order to satisfy this requirement, the rubber stamp was proposed as a tool for manufacturing. Typical press forming process defects were identified and the requirements for rubber stamp were described. It was assumed that the forming process has to begin at one point on mould surface and sequentially continue in all directions. For stamp material, the two components additive silicone was selected. The hardness of the silicone was equal 40 Shore A. The rubber mechanical properties was determined through the additional tests and used for stamp designing. The tooling was designed using FEM software ABAQUS 6.12.
The sequence of stamp shape designing and optimization in order to meet the stamp requirements was presented. At the end the FEM rubber stamp designing recommendation were presented.
The conducted tests were aimed at determination of the drop diameters and shaping of the velocity field at different configurations of the test injector. The test results allowed defining the relationship between the injector configuration and the distribution of velocities and dimensions of drops in the fuel stream. The effect of the fuel viscosity and injection pressure on the dimensions of fuel drop diameters and the distribution of the velocity field of drops in the stream were tested. The tests were carried out on a special test rig with a fixed volume chamber. The measurements were carried out with the use of laser Doppler measurement systems (PDPA, LDV). The tests were conducted for seven different fuel types varying in viscosity and surface tension. In addition, the injection pressure from 50 MPa to 130 MPa was applied. The test results allowed determining the relationship between the injector structure configuration, fuel types and fuel additives, and the distribution of velocity and an atomisation spectrum of drops in the fuel stream, and the air impact on the fuel stream.
In metal cutting industries, machining processing, especially turning operation is very basic type of machining. For certain processes in manufacturing, it is favourable and necessary to have certain knowledge about heat generation and temperature rise (including average and maximum temperature) during machining process. Increment in maximum temperature at clearance face or at rake face of cutting tool causes the reduction in life of tool. Similarly, the quality of machined surface, a metallurgical structural alteration in tool and workpiece material also depends on the maximum temperature, temperature gradient and cooling rate of both tool and workpiece. Certain physical and chemical reactions that are developed during the cutting process are directly connected with tool wear, power consumption, surface roughness on work piece material and cutting temperature. The natural low of thermal energy gives significant relationship between cutting temperature and cutting parameters in order to improvement of cutting tool’s wok efficiency, quality and accuracy. The heat distribution in cutting tool, in formed chip and in workpiece material strongly depends on (mechanical and chemical) properties of cutting tool and workpiece material, cutting speed, depth of cut, feed rate, nose radius, geometry of tool, type of coolant used and other parameters. This work presents some results of research done during turning steel 235JR realized on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process temperature, realized for different materials.
The article presents a non-destructive welded joints assessment (vibrodiagnostics) method, in which, with the use of the Internet, computer networking technologies and laser displacement sensors, the quality of welded steel plates may be monitored. The article also describes the possibilities of analysis of received vibrodiagnostics data on the base of diagnostic parameters analysed in function of time and frequency. The method described in the article allows remotely registering, analysing and diagnosing mechanical systems using vibrodiagnostics and information technologies. Modern, computerized methods exhibit efficiency and reliability of results – they are currently the best measuring tools that can be used in automatic monitoring (structural health monitoring - SHM) of marine structures. It is essential to make objective assessment of the results by NDT users, which is tightly connected with the expertise of norms and regulations of NDT. It may be helpful in this respect to monitor responses from a few sensors, arranged in a few measuring points. NDT results quite often trigger further analysis of durability of an object. The NDT of welded joints method as presented in the article allows remotely and in an IT-aided way analysing and diagnosing mechanical systems with the use of vibrodiagnostics method.