Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "flow analysis" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
A computational fluid flow analysis of a disc valve system
Autorzy:
Czop, P.
Śliwa, P.
Gniłka, J.
Gąsiorek, D.
Wszołek, G.
Powiązania:
https://bibliotekanauki.pl/articles/244640.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
valve system
computational fluid flow analysis
simulation
Opis:
Noise concerns in shock absorbers can be divided into two categories. The first is fluid flow noise, or “swish noise”, caused by the oil being forced through openings in the valves. The type and temperature of the oil, its velocity and the orifice geometry all have an effect on this. In addition, the structural design of the shock absorber shell may either reduce or amplify the noise. The second type of shock absorber noise is often described as regular operational noise or “chuckle noise”. It can be observed in vehicles during low-displacement, higher-frequency events, such as driving over a slightly rough road. This effect measurable as a force discontinuity into the vehicle and can come from a number of sources in the shock absorber, e.g. hydraulic transitions. It is often traceable to the valve discs closing and opening, but can also be caused by cavitation/aeration in the oil and air being pulled through the valves. The work on noise improvement reported in this paper has been started using conventional shock absorbers to be extended and will cover in the future variable damping shock systems as well. The paper gives an overview about the configurations of a typical valve system including three basic regimes of operation, which correspond to the amount of oil flowing through a valve cavity. The aim of this work was to propose a finite element fluid flow model, which can be used in order to reduce the velocity of fluid flow through a cavity of a shock absorber valve. High flow velocity can cause high-content frequency vibrations and, in turn, audible noise. The model will be used for initial screening of new valve concepts and on the other hand to improve the currently use ones.
Źródło:
Journal of KONES; 2011, 18, 1; 117-122
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of a velocity distribution of a fluid flow inside a reversing chamber
Autorzy:
Judt, W.
Bartoszewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/242487.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
numerical analysis
reversing flow
fluent
axisymmetric flow
Opis:
Axisymmetric stream, which is directed into an obstacle, is an important type of a fluid flow for technical applications in a large amount of thermal and flow devices. The article presents a case wherein stream of a fluid is directed into a flat surface and changes the direction of a flow by an angle equal to 90°. After that, the free stream is changing a character of a flow into impinging stream. The article presents a methodology of numerical calculations preparation in ANSYS Fluent environment for a velocity distribution of an airflow inside a reversing chamber. Numerical calculations were prepared for a three-dimensional model as an unsteady simulation with Delayed Detached Eddy Simulation model of turbulence. A stream of an air, which was analysed inside a reversing chamber, was not initially swirled. Obtained results of realized calculations were compared with experimental analysis and numerical calculations, which was realized in a different environment by co-author. Model of reversing chamber, which was implemented into numerical analysis has the same dimensions as used in experimental research. Obtained results show areas of intense flow turbulence inside reversing chamber. Prepared numerical calculations agreed with experimental results of research and allowed to designate areas of stream core and impinging stream inside modelled chamber.
Źródło:
Journal of KONES; 2018, 25, 3; 247-251
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysing the cavitation phenomena in in-nozzle flows
Autorzy:
Vajda, B.
Žunič, Z.
Kegl, B.
Powiązania:
https://bibliotekanauki.pl/articles/247508.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
two-phase flow
cavitation
injector nozzle
CFD
nodalisation analysis
Opis:
The geometry of the diesel fuel injection nozzle and fuel flow characteristics in the nozzle significantly affects the processes of fuel atomization, combustion and formation of pollutant emissions in diesel engine. To improve the process of fuel injection, CFD packages are used. Since CPU times are often high, partial models are used for the analysis. In presented paper the influence ,of different density of mesh on the cavitation phenomena is being analysed. The theoretical backgrounds of the cavitation occurrence presented in the first part of the paper are followed by the numerical analyses of two-phase flow in same simplified nozzle models. The numerical analyses are made using computation fluid dynamic (CFD) program Fire. The numerical analysis is made for two different types of fluid, diesel (D2) and biodiesel (B 100). Numerical analysis also includes various densities of meshes and their influence on results. The two-phase flow is analysed using a two-equation approach, where all conservation equations are solved for every phase. Numerical analysis results are compared to the experimental observations of the two-phase flow available from the literature. The results are compared for various meshes and various fluid types. The results show that higher pressure yields mode cavitation and point out the importance of mesh densities.
Źródło:
Journal of KONES; 2010, 17, 2; 475-482
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of light aircraft in domestic transport in Poland
Autorzy:
Kołodziejczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/241893.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
small aircraft transport
domestic air transport
routes analysis
passengers flow
Opis:
The work concerns the analysis of the possibilities of using light aircraft in the regional passenger transport. This analysis was based on the existing airport infrastructure in Poland. Between 43 existing airports with paved runways and length more than 1,000 meters potential routes of aircraft traffic were set. The study compared the light aircraft transport to the car transport. One of the benchmark criteria was the travel time between different destinations, using both means of transport. The second criterion is the financial aspects of travel. For this purpose, a statistics of light aircraft and calculated their Direct Operating Cost as a function of various parameters such as maximum weight, the number of passenger seats, cruise speed were created. Analysis also included air navigation charges on the routes and the operator profit. The calculations allowed identifying potential routes where the plane would be competitive with the car in terms of travel time and costs by one person. The number of these routes was dependent on the speed of travel, the number of seats on the plane as well as the fill factor of these seats. The analysis also applies to determine the number of passengers traveling between the regions. In 2013, domestic air transport handled less than 2.5 million passengers, which in comparison to the countries of Western Europe is a poor result. This is caused mainly by a small amount of domestic routes as well as a small number of regional airports. The implementation of the concept of using light aircraft in regional connections aims to increase the speed of travel, increase the safety in passenger transport, cost reduction and partial replacement of road transport by air transport.
Źródło:
Journal of KONES; 2014, 21, 4; 239-246
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies