Vyskumny Ústav Dopravny

Intermodal and combined container transportation is an inseparable part of a sustainable transportation system. Railway transport, in combination with railway ferry services, plays a crucial role within this system. The research presented in this contribution highlights the features of studies on the loading of a universal container when transported by a railway ferry. This research consisted of two stages: a study of the strength of a universal container when transported by a railway ferry, and a study of the container’s stability relative to the frame of a flat wagon. The calculation of the container’s strength was carried out using the finite element method, which is implemented in SolidWorks Simulation. It was established that the stresses in the container structure in the case of its placement on the track farthest from the bulwark exceed the permissible ones by 23%. When the container is placed on the track second from the bulwark, as well as on the middle track, the stresses are within the permissible limits. Studies of the stability against overturning of the container relative to the flat wagon frame showed that in the case of its placement on the track farthest from the bulwark, the container does not maintain equilibrium stability. Therefore, it is recommended to place flat wagons with containers on the track second from the bulwark or the middle tracks. The results of the research will contribute to the creation of recommendations for the safe transportation of containers in combined transport trains by sea, as well as the sustainable development of international freight transportation.

In this paper authors designed, developed, and verified a measurement apparatus (vibration rig) for the simulation and subsequent condition monitoring of operational bearing defects as an analogy of critical and indispensable engine components. The time-domain and frequency-domain analysis is applied on collected vibration signals to identify the defects by comparing the reference and simulated conditions. In addition, the paper pinpoints and describe the main attributes of three current advanced signal processing methods with potential applications in specific areas of condition monitoring processes for critical aero engine parts such as bearings, shaft, blades, etc. The vibration rig as well as the data obtained from presented testing can serve as a benchmark for comparison with the results of the proposed methods applied to various components in future research to validate their effectiveness in the above applications.

The article considers the possibility of using biogas for vehicle engines, as an additive to compressed natural gas, and gives the results of experimental studies of environmental indicators and fuel efficiency of a vehicle equipped with a gasoline engine and converted to work on a mixture of biogas and compressed natural gas. Currently, there are many vehicles in operation that operate without feedback on the content of oxygen in the exhaust gases, they run on gasoline and gas motor fuels, in view of this, the results of these studies are very relevant. It has been proven that the use of biogas as motor fuel for vehicle engines reduces the energy dependence on petroleum fuels and reduces emissions of harmful substances in the exhaust gases of the vehicle engine, and the use of biogas as an additive to compressed natural gas will provide an opportunity not to spend additional resources for its purification. The use of biogas as a motor fuel confirms the possibility of its use in traditional constructions of vehicle engine power systems. With simple, reliable and proven production technologies, biogas can become a cost-effective and efficient type of fuel obtained from renewable sources. In this way, it is possible to satisfy these needs by using alternative types of fuels, one of these types of fuels is biogas, which is obtained in the process of anaerobic decomposition of organic waste. Biogas consists of methane CH4, carbon dioxide CO2, small amounts of carbon monoxide CO, hydrogen H2, nitrogen N2, oxygen O2, water vapor H2O and hydrogen sulfide H2S. The possibility of using a mixture of fuels, namely biogas as an additive to compressed natural gas, is substantiated. A comparative analysis of the fuel-economical and environmental performance of the vehicle engine in the modes of the European urban driving cycle was performed while the engine was running on compressed natural gas, a mixture of biogas and compressed natural gas, and liquid petroleum fuel gasoline brand A-92

During an aircraft’s flight through the atmosphere, the aircraft structure interacts with the surrounding environment. One of the potential hazards that can occur is a lightning strike to the structure covering. Subsequent damage to the aircraft covering may cause safety risks, so it must be removed. This paper describes a method of producing an electrical discharge that simulates the effect of lightning on metallic and non-metallic types of aircraft coverings upon which various types of paint coatings are applied. The electrical discharge hits the coating samples and, based on the material and type of paint used, causes damage. The coatings were later tested in a salt chamber according to STN ISO 9227:2017, and were photodocumented at various time intervals and subsequently analysed. The salt chamber test exposes the material to adverse conditions, which, in relation to the damaged coating, cause corrosion of the material, which depends on the extent of the damage and the type of material. The paper concludes that metallic aircraft coating samples allow less damage to aircraft coverings after a lightning strike, which is linked with less required maintenance associated with financial and time costs.

Nowadays, Unmanned Aerial Vehicles are only being utilized in a limited number of sectors, such as agriculture, cinematography, photogrammetry, or research. The implementation of formation flight could greatly enhance the applicability and make the UAVs operate more effectively. This paper analyses the contemporary state of implementation of UAVs in conditions of their flight in formations, mechanisms by which the formations are coordinated and proposes their further use in the future. We also analyse the possibilities and use cases of development of technology applicable for coordination of multiple UAVs flying in formations. Furthermore, we discuss implementation of advanced mission planning and swarming software, on the usage of specifically chosen hardware and structural components for construction of advanced UAVs capable of coordinated flight in formations or swarms. These formations are configurable to take form of various shapes dependent of the particular application demanded by the operator. For instance, UAV formations could be greatly utilized by delivery companies, for search and rescue purposes or intra city medical material transport between hospitals. All analyses, data collection, monitoring and control are done virtually. This methodology serves to optimalization the swarm flying, without the need of real experimental flights.

The use of digital technologies has become popular in recent years. Digital technologies can be found almost in every sector, with the transport sector being no exception. The Covid-19 pandemic has brought a number of restrictions, which have resulted in various measures being taken to reduce the spread of the virus. Therefore, in some cases, it was necessary to introduce digital technologies, in particular the elimination of personal contact, in order to reduce the spread of the virus. Airports had to adapt to this situation if they wanted to survive, so they began to apply various smart solutions to protect passengers' health as much as possible, which of course encouraged digitization at small and regional airports as well. At present, not all regional airports are digitized, whereas efforts to implement digital technologies are very strong. The main goal of this paper is to find out which digital technologies are currently used by regional airports in the Slovak Republic and Czech Republic, and what digital technologies have been introduced as a result of the pandemic. Research has shown that regional airports want to adapt and implement digital technologies, but this is not possible due to their poor financial situation and minimal traffic.

The year 2019 is possible to consider as an extraordinary in the history of mankind. The sudden outbreak of Covid-19 virus in China has had a significant impact on daily life. The situation worsened over the weeks, so much so that a global pandemic broke out, and it was accompanied by a slowdown in the world economy. From another point of view, the pandemic caused a reduction in incomes in families, a deepening of poverty, mental problems of people, high unemployment, inflation, or interruption of the educational process in schools. Closed borders and strict rules have caused that all kinds of traffic suffered. The difficult situation was perceived by air transport, where the decline in passengers caused the bankruptcy of airlines, the grounding of aircraft and the overall decline of the sector. This paper is focused on the impact of the Covid-19 pandemic on civil aviation and the measures put in place to mitigate the spread of the Covid-19 virus. The article briefly assesses previous crises that have affected civil aviation. Then it describes the measures and changes that had to be applied in air transport to mitigate the impact of the corona crisis. From a legal point of view, it analyses the legislative solutions that were suggested by the European Union, and It evaluates the approach of the Slovak government to rescuing airports.

In recent years, we can observe a lack of trainer aircraft suitable for initial and also for advanced aerobatics training. In addition, it should be mentioned that Upset Prevention and Recovery Training provision has been applied, which has increased the demands on the capabilities of trainer aircraft. This paper is devoted to introducing the conceptual design of an aerobatic trainer two-seater aircraft with a tandem arrangement. The introductory part is aimed at a state-of-the-art review of the aerobatic aircraft portfolio. The main section of the paper discusses the design creation of a training aerobatic aircraft in the software Rhinoceros and the determination of technical and operational parameters. Analyses of aerodynamic characteristics precede the conclusion.

The paper deals with the solution of the issue of achieving customer satisfaction of the postal company. Through the diagnostic procedures used in quality management in services, the focus is on the application of KANO model as one of the customer satisfaction measurement models. The primary research carried out in four different districts of Slovakia identified the relationship between customer satisfaction level and quality attributes through 5 categories of perceived quality by customers. The categories were identified as attractive, one-dimensional, mandatory, insignificant and contradictory attributes of postal products that create their quality parameters and reflect the requirements of customers. Significant findings concern mainly the identified differences in survey results in individual selected districts of Slovakia. There were also differences in the categories of postal quality requirements in respondent segments that differed in gender, residence, or age of respondents. One of the conclusions of the solved issue is to propose framework therapeutic procedures in response to individual diagnostic statements that resulted from the performed research activities.

Abstract The article deals with issues, which may arise during the preparation of line infrastructure projects in the public interest such as airports, railways or highways. We focused mainly on the issue of expropriation of land in the public interest and related problems in Slovakia and Croatia but also in other states. Few case studies complement the theoretical part of the study. The paper is focused on comparison of selected national legislation especially Slovak and Croatian in this field and individual State’s approaches and tries to find the necessary changes in legislation whose could be usefully for the future. Slovakia and Croatia were chosen for comparison because not only they have a similar population and number of public airports, but they also have a common history and had common legal framework where, after the Austro-Hungarian settlement in 1867, Croatia itself belonged to Zalitavsko within Austria-Hungary together with Slovakia.