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The paper presents the results of calculations related to the flow analysis of gases in a model tube bank of a condenser. Different mass share of the gas not condensing in the heat exchanger upstream of the first row of tubes and the partial pressures of water vapor and air have been taken into account. The value of the partial pressures of gases, pressure drop, temperature, velocity, Reynolds number,...
Pin joints are very popular couplings in applied mechanical engineering. A lot of constructions and mechanisms are equipped with such type of kinematic pair. Pin joints are often applied as hinge connections in many responsible assemblies such as engine parts, bridges set systems, cranes etc. These connections work in different operating conditions which play a fundamental role during the design process...
W artykule przedstawiono podstawowe parametry określające resurs nowoczesnego silnika odrzutowego. Za ich pomocą możliwe jest określenie stopnia jego zużycia. Określają one również wielkość zapasu pracy silnika, jaka pozostała do jego naprawy lub zakończenia eksploatacji. Przedstawiono metodę zliczania cykli pracy silnika. Opisano różnice pomiędzy jego użytkowaniem w lotnictwie cywilnym i wojskowym.
A detailed analysis of the issues related to improving the efficiency of energy conversion in spark ignition engine, powered by low-carbon gaseous fuels are presented in that monograph. The research was conducted on engine powered by compressed natural gas (CNG), and methane/hydrogen blends. Selected for tests group of fuels was consisted of eight blends, with various hydrogen share (by volume): 0%...
This work describes an effective method of creating digitally reconstructed radiograph images. Developed algorithm is based on standard mathematical calculations reducing the necessity of usage sophisticated software and libraries. There is also no need to go through any special training to use it. Presented solution allows creating digitally reconstructed radiographs (DRR) from computer tomography...
The article presents a variety of the meanings of an object state term (notion), depending on the point of view at which it is discussed. Each of the presented meanings can constitute an identification subject in contemporary operational states. The first of these meanings is a structural state of an object. It refers to the number of the elements active in a given set and the interactions between...
This paper presents the results of indicator research of transient states of an engine operating in the Atkinson cycle. Such states are the most frequently observable ones during engine operation and are a subject of many researches and development works. The investigations were carried out using a fast varying data acquisition system using engine speed sensor and the pressure sensors fitted in the...
The application of timing belts into new usage fields makes them more and more popular, and at the same time cause the necessity of introduction of their new construction. It became possible mainly thanks to the usage of new materials and modern production processes. The modernization of timing belts construction affects the reliability and functionality of timing belt gears. New properties allow...
This article covers how commercial air traffic in Europe changed during the last ten years in statistical terms, how air traffic will look in the nearest future and how aerospace engineering conform current and future noise emission regulations. Based on EUROSTAT statistical data article shows changes of: total European fleet, total number of passengers and number of airports. Future state prognoses...
In last years increase number of aircrafts makes a lot of benefits, but they have also brought negative effects. This is mainly due to an increase of air traffic noise and increase of toxic gases emissions. Substances emitted from the main aircraft engines are carbon dioxide CO2, unburned hydrocarbons HC, carbon monoxide CO, nitrogen oxides NOx, particulate matter PM (mainly soot and heavy hydrocarbons...
The paper presents the simulation model of passenger handling process being conducted at the Poznań-Ławica Airport. The first part is theoretical, containing an overall outline of the passenger handling processes and their meaning when concerning airports capacity. Second part of the paper is a presentation of a simulation model construction. The main goal of this paper was to model the departure...
The article presents the research results concerning the application of the selected function characteristics in the domain of the amplitudes in a vibration signal for the valve clearance assessment in the internal combustion engine. It is pointed out here that before the calculations of the characteristics describing the vibroacoustic signal - for to make smaller the risk of the incorrect assessment...
This paper describes a proposed pneumatic positioning system differing in terms of operation from conventional systems produced in Poland and in other countries. The proposed solution is free of the main problems typical of the operation of pneumatic positioning systems. The system ensures maintaining the desired position and features shorter cycle time, higher average velocity of the piston movement...
In the article, an excerpt of conceptual and design work on the universalist transport rehabilitating system for physically disabled and elderly people has been presented. In the introduction, the author has explained the reasons of his study on the above mentioned system and has described the differences in the functional potential of various types of wheelchairs. Next part of the study presents...
The paper presents selected aspects of the technical condition of the vehicles operating in Poland, the quantitative status of a selected group of vehicles and the requirements to be met during compulsory inspections at diagnostic stations in terms of exhaust emissions. The results of studies have been presented and they indicate a group of vehicles which do not meet the required limits of exhaust...
This paper presents the results of simulation studies of dynamic ''Modular system combined transport'' developed in IPS TABOR, used for the transport of semi-trailers. Due to the specific design of combined transport platforms is necessary to couple two of such vehicles. Otherwise it would not be possible to configure a train consisting of wagons, because of the survey was conducted just for this...
The aim of this research was to evaluate the influence of laser alloying with corundum on microstructure and hardness of surface layer of nodular cast iron. The molecular CO2laser with 2600 W output power and TEM01mode was used to perform surface modification. An optical microscope and hardness Vickers tester were used to assess the result of the surface modification. The research showed, that it...
The paper presents the state of ignorance as a result of the analysis of the present GPS rules in drawing, interpretation and verification of geometrical features of a construction. On the basis of the fragments of production drawings of connections which are applied in mechanical engineering, it was proved that the knowledge of the application rules and interpretation of the tolerance of form in...
Poznan University of Technology is an important center of education which attracts students from distant cities. The university significantly affects the economy of the city of Poznan, as well as the nearby towns. The majority of the students rent apartments or rooms, use public transport to commute to the college, buy in Poznan stores, visit cultural centers or dine in restaurants, etc. Currently...
Carbon nanotubes, since they were identified in 1991 by Prof. S. Iijmia, have been an object of interest for almost all fields of science and industry. Their properties are tested continually, both in the micro and the macro scales. It is predicted nowadays that all three types of nanotube structures have the greatest chances to be applied in electronic and medical industries. Authors of this paper...
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