Informacja

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

Wyszukujesz frazę "pressure distribution" wg kryterium: Temat


Tytuł:
Numerical analysis of turbulent flow around twodimensional bodies using non-orthogonal body-fitted mesh
Autorzy:
Tarafder, M. Shahjada
Mursaline, M. Al
Powiązania:
https://bibliotekanauki.pl/articles/947300.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ turbulentny
objętość
rozkład ciśnienia
turbulent flow
finite volume method
pressure distribution
Opis:
This paper deals with the numerical simulation of a turbulent flow around two-dimensional bodies by the finite volume method with non-orthogonal body-fitted grid. The governing equations are expressed in Cartesian velocity components and solution is carried out using the SIMPLE algorithm for collocated arrangement of scalar and vector variables. Turbulence is modeled by the turbulence model and wall functions are used to bridge the solution variables at the near wall cells and the corresponding quantities on the wall. A simplified pressure correction equation is derived and proper under-relaxation factors are used so that computational cost is reduced without adversely affecting the convergence rate. The numerical procedure is validated by comparing the computed pressure distribution on the surface of NACA 0012 and NACA 4412 hydrofoils for different angles of attack with experimental data. The grid dependency of the solution is studied by varying the number of cells of the C-type structured mesh. The computed lift coefficients of NACA 4412 hydrofoil at different angles of attack are also compared with experimental results to further substantiate the validity of the proposed methodology.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 2; 387-410
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oil pressure distribution in variable height gaps
Rozklady cisnienia oleju w szczelinach plaskich o zmiennej wysokosci
Autorzy:
Zloto, T.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/792863.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
variable height gap
pressure distribution
hydraulic oil
hydraulic machine
Navier-Stokes equation
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2011, 11C
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of the impact of a cone opening angle parameter on the hydrodynamic lubrication of the conical slide bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/242697.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
slide bearing
conical bearing
cone opening angle
CFD
pressure distribution
Opis:
The height of the oil lubrication gap is the primary quantity that determines in simulations the operating parameters of a hydrodynamic slide bearing. It is influenced by multiple effects, such as vibrations during operation, varying load, misalignment between the shaft axis and the axis of the bearing sleeve, the roughness of the journal and sleeve surfaces, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces etc. It is important to take into account such effects considering hydrodynamic lubrication simulations and design of the slide bearings. The one of the factors influencing the height of the oil lubrication gap of the conical slide bearing is the difference between the opening angle of the cone of bearing shaft and opening angle of the cone of bearing sleeve. The aim of this work is to investigate the impact of the difference between the values of these angles on the hydrodynamic lubrication of the conical slide bearing. The commercial CFD software Ansys Fluent, from the Ansys Workbench 2 platform, was used to determine the hydrodynamic pressure distributions, load carrying capacities and friction torques of the simulated bearings. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal, there is no misalignment between the axis of bearing journal and axis of bearing sleeve, the surfaces of the journal and sleeve are smooth and lubricating oil acts as a liquid described by the Ostwald-de Waele power law model.
Źródło:
Journal of KONES; 2016, 23, 3; 71-77
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alternative FEM algorithm of determining piston ring pressure distribution on a cylinder to a contact simulation
Autorzy:
Kaliszewski, M.
Mazuro, P.
Powiązania:
https://bibliotekanauki.pl/articles/793393.pdf
Data publikacji:
2016
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
finite element modelling
algorithm
piston ring
pressure distribution
contact simulation
ANSYS programme
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2016, 16, 4
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the stern wedge length and height on the drag and trim of a chine-planing hull
Autorzy:
Ghassemi, Mohammad A.
Ghadimi, Parviz
Sajedi, Sayyed Mahdi
Powiązania:
https://bibliotekanauki.pl/articles/2033606.pdf
Data publikacji:
2021
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
chine-planing hull
stern wedge
wedge width and height
drag
trim
pressure distribution
Opis:
This paper examines the effect of the stern wedge length and height on the drag and trim of a chine-planing hull in calm water. To this end, fluid flow was simulated by Star-CCM+ software by applying an overset mesh and k-ε turbulent model. The finite volume method was used to discretize the fluid domain, and the fluid volume was utilized to capture the generated free surface. The considered model is a prismatic planing hull with a deadrise angle of 24°, a mass of 86 kg, a length (L) of 2.64 m, and a beam (B) of 0.55 m. For validation, the numerical results of drag and trim were compared against experimental data, which displayed good compliance. Subsequently, the hydrodynamic performance of the planing hull was investigated, and the wedge effect was assessed. The stern wedge was located at the bottom and near the aft perpendicular to the hull to facilitate a moderate distribution. Various wedge lengths of 0.2B, 0.5B, and B at two different heights of 5 mm and 10 mm were examined to assess the hydrodynamic performance of the hull at various speeds. The trim angle, resistance, water surface elevation, porpoising, roster tail, and the stern and bow were computed and analyzed. Based on the numerical results, it was concluded that when the wedge length increased, the drag and trim were reduced. It was also concluded that the best wedge for a vessel with desirable wake generation is one with a length of 0.2B and a height of 5 mm.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2021, 67 (139); 39-52
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental verification of a model of the loss of fluid friction in a hybrid thrust bearing
Eksperymentalna weryfikacja modelu utraty tarcia płynnego w hybrydowym łożysku wzdłużnym
Autorzy:
Salwiński, J.
Grądkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/187962.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
łożysko wzdłużne
smarowanie hydrostatyczne
pomiar rozkładu ciśnienia
thrust bearing
hydrostatic lubrication
pressure distribution measurement
Opis:
One of the known solutions of thrust bearings for heavy machines is a hybrid slide axial bearing composed of a set of bearing pads supported on sets of compression springs. During operation of such a system, a series of failures have been observed. The failures were caused by inappropriate parameters of the supporting springs and the appearance of an adverse system of forces acting on the bearing pad. The paper presents the results of experiments in which pressure distribution in a bearing interspace of a model hydrostatic thrust bearing was measured. The research goal was to verify an earlier formulated quantitative model, describing the conditions at which the mentioned failure occurred. The results of the experiment confirm the legitimacy of the proposed model.
Jednym ze stosowanych rozwiązań łożyskowania wzdłużnego ciężkich maszyn jest łożyskowanie w hybrydowym ślizgowym łożysku wzdłużnym, złożonym z segmentów wspartych na elementach sprężystych. W trakcie eksploatacji takiego układu zaobserwowano szereg awarii, polegających na niezamierzonym metalicznym kontakcie powierzchni ślizgowych. Awarie były spowodowane niewłaściwymi parametrami sprężyn wspierających segmenty i wystąpieniem niekorzystnego układu sił działających na segmenty łożyska. W pracy zaprezentowano wyniki badań stanowiskowych rozkładu ciśnienia w szczelinie smarnej modelu hydrostatycznego łożyska wzdłużnego. Badania służyły weryfikacji, sformułowanego wcześniej, modelu jakościowego opisującego warunki wystąpienia opisanej awarii. Wyniki badań potwierdzają słuszność zaproponowanego modelu.
Źródło:
Tribologia; 2010, 3; 199-208
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of non-Newtonian and non-isothermal lubrication of hydrodynamic conical bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/243876.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
non-isothermal flow
pressure distribution
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of non-isothermal oil flow in a bearing lubrication gap and also with assumption, that oil has non- Newtonian properties. The determination of hydrodynamic pressure distribution in bearing gap was carried out by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were performed for bearings without misalignment, i.e. where the cone generating line of bearing shaft is parallel to the cone generating line of bearing sleeve. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that the flow in the bearing lubrication gap is isothermal. Some other simplifying assumptions are: a steady-state operating conditions of a bearing, incompressible flow of lubricating oil, no slip on bearing surfaces, pressure on the side surfaces of bearing gap is equal to atmospheric pressure. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 4; 49-56
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing
Autorzy:
Koprowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/260459.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
unsymmetrical lubricating gap
conical slide bearing
numerical calculations
hydrodynamic pressure distribution
load carrying capacity
Opis:
This paper presents a computer analysis of lubricating medium flow through unsymmetrical lubricating gap of conical slide bearing. Numerical calculations were carried out with the use of the software Matlab 7.1 and Mathematica 5.2 for example conical slide bearings of different values of cone apex angles of pin and sleeve and set values of relative eccentricity and skewing angle as well as dimensionless bearing length equal to 1.
Źródło:
Polish Maritime Research; 2007, 4; 59-63
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of total inertia effects in a thrust curvilinear bearing lubricated with Newtonian lubricants
Autorzy:
Walicka, A.
Jurczak, P.
Powiązania:
https://bibliotekanauki.pl/articles/265900.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
inertia
modified Reynolds equation
pressure distribution
load-capacity
bezwładność
równanie Reynoldsa
rozkład ciśnienia
nośność
Opis:
In the paper, the flow of a Newtonian type of lubricant in the clearance of a curvilinear bearing is considered. It is assumed that the bearing walls are modelled as smooth and impermeable. In analytical considerations, full inertia of the longitudinal flow and partial inertia of the circumferential flow are taken into account. The equation of motion of the lubricant is solved by the modified method of averaged inertia. A thrust bearing and spherical bearing are considered, for which dimensionless pressure distributions and the bearing capacity are given.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 4; 1045-1058
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insights into hydrodynamics of spinning fluids reactor
Autorzy:
Dargacz, A.
Aranowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/109782.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hydrodynamics
spinning fluids reactor
pressure field distribution
separation
flotation
Opis:
Spinning fluids reactor (SFR) is one of the most efficient gas-liquid contacting system with high potential of application in many fields. The unique solution of SFR is the contacting of two spinning fluids which generated centrifugal force. The aim of this study was to investigate the pressure field distribution on the inner surface of reactors dispersing element. Obtained results confirm the high heterogeneity of the field pressure in the reactor system with a cylindrical wall. This is due to the low tangential force generated by rotating liquid on a cylindrical wall, and pressure drop in the locations of surface irregularities. The change of the sparger element to conical shape element increases the pressure exerted by fluid on the wall. In this case the effects of solid particles and inequality in the fluid flow are negligibly small compared to the measured pressure exerted on the sparger element.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 173-183
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiana ciśnienia w poprzecznym łożysku ślizgowym przy laminarnym niestacjonarnym smarowaniu
Variation of Pressure in a Slide Journal Bearing with Laminar Unsteady Lubrication
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/359411.pdf
Data publikacji:
2006
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
łożyska ślizgowe
EXPLO-SHIP 2006
równanie Reynoldsa
rozkład ciśnienia
journal bearing
Reynolds equation
pressure distribution
Opis:
W artykule przedstawiono przykład rozwiązania numerycznego zmodyfikowanego równania Reynoldsa dla laminarnego niestacjonarnego smarowania poprzecznego cylindrycznego łożyska ślizgowego. Przyjęto izotermiczny model łożyska o nieskończonej długości, smarowanego olejem o własnościach newtonowskich i lepkości dynamicznej zależnej od ciśnienia. Wyznaczono rozkłady ciśnienia hydrodynamicznego w łożysku przy zaburzeniach prędkości przepływu oleju w kierunku obwodowym na czopie i na panewce.
This paper presents the results of numerical solutions modified by the Reynolds equation of laminar unsteady lubrication of a cylindrical slide journal bearing. The particular solutions are limited to isothermal models of bearing with infinite length, lubricated by Newtonian oil with the dynamic viscosity dependent on pressure. The disturbances are related with unsteady velocity of oil flow on the sleeve and on the journal. The results are shown in the diagram of hydrodynamic pressure in the dimensionless form in time intervals of displacement duration.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2006, 10 (82); 287-298
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of oil’s exploitation time on load carrying capacity in a slider bearing
Autorzy:
Sikora, G.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/244279.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
oil ageing
numerical calculations
Reynolds equation
pressure distribution
load carrying capacities
viscosity changes in time
Opis:
In this paper, authors are presenting conclusions of the numerical calculations of pressure distribution and capacity in a slider bearing with taking changes of oil viscosity in exploitation time into account. Changes of the engine oil’s viscosity, which depend on the exploitation time, were determined on Haake Mars III rheometer and the conclusions were published in Solid State Phenomena and Logistyka in 2015. Numerical calculations were performed by solving of Reynolds equation, using finite difference method and own calculation procedures in Mathcad 15. Reynolds equation was developed by solving the continuity equation and the momentum conservation equation from the fundamentals. For the considerations, the laminar and stationary lubricating of the slider bearing of finite length and full angle of wrap were taken. Assumption of the stationary flow concerns lack of changes in flow parameters in short period of considered phenomena, f. ex. in one hour. Smooth and non-porous bushing were assumed. The aim of this paper was preliminary estimation of influence of viscosity changes in the exploitation time on the load carrying capacities of the cross slider bearing. Wherefore, the viscosity changes dependence on the pressure, temperature and also shear rate, were not taken into account. The basic equations were developed to the non-dimensional form and estimated according to the thin layer theory. In the calculations, the Reynolds boundary conditions concerning pressure distribution were taken into account. Preliminary calculations were performed for different models of viscosity changes in time and circumstances, where the viscosity increases and decreases in exploitation time.
Źródło:
Journal of KONES; 2015, 22, 3; 207-212
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of hydrodynamic lubrication of slide conical bearing with consideration of the bearing shaft and sleeve surface roughness
Autorzy:
Czaban, A
Powiązania:
https://bibliotekanauki.pl/articles/246600.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
surface roughness
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
pressure distribution
sand-grain roughness
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of the effect of the bearing shaft and sleeve surface roughness. The oil flow in a bearing lubrication gap largely depend on the condition of the cooperating surfaces of a bearing. Surface irregularities are formed already at the manufacturing process and furthermore the quality of the surface may change during operation of a bearing. In this work, as a parameter describing surface condition, the Ks roughness height parameter was taken (i.e. sand-grain roughness height). The hydrodynamic pressure distribution in lubrication gaps of investigated bearings were calculated by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were conducted for bearings without misalignment. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that bearings have smooth surfaces and there is no slip on surfaces. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 3; 35-40
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does B.I.R.D foot control supply sensitivity disturbance induced by EMLA cream anaesthesia
Autorzy:
Descatoire, A.
Moretto, P.
Powiązania:
https://bibliotekanauki.pl/articles/333485.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
urządzenia biologicznego sprzężenia zwrotnego
rozkład ciśnienia podeszwowego
obciążenia stopy
biofeedback devices
plantar pressure distribution
foot unloading
Opis:
Numerous studies on the development of new biofeedback device conception have already been undertaken. Patients with loss of protective pain sensation are unable to modify their gait when abnormal and excessive plantar pressure occurs. For this reason, we have developed and tested a portable baropodometric biofeedback, on healthy subjects, to prevent injuries by informing the subject when local pressure exceeds a determined threshold. Anaesthesia cream enables us to determine the ability to use our device with a perturbation of the plantar sensory inputs. Results showed 58.2% of success steps in the EMLA condition while the placebo condition showed 57.5% of success steps.
Źródło:
Journal of Medical Informatics & Technologies; 2008, 12; 123-127
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Baro-paedometric biofeedback for foot unloading procedures investigation
Autorzy:
Descatoire, A.
Moretto, P.
Powiązania:
https://bibliotekanauki.pl/articles/333748.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
urządzenia biologicznego sprzężenia zwrotnego
rozkład ciśnienia podeszwowego
obciążenia stopy
biofeedback devices
plantar pressure distribution
foot unloading
Opis:
Numerous studies on new biofeedback devices conception development were undertaken. They are used for some compensation methods of the data lost on sensors set. The aim of the study was carried out for introducing several approaches of investigations and testing of the biofeedback devices that support a plantar pressure analysis, for foot unloading processes implementation. The healthy man is walking in normal conditions first; on a walkway. The recorded load on 6 sensors has to be reduced next in a specified area. The pressure was considered at the beginning on metatarsal head, in time of 100 steps. The visual and auditory signals were then adjusted to a specific plantar pressure threshold setting. The peak pressure was evaluated for various walking condition. The introduced device enables us reducing the peak plantar pressure within the appointed risk-regions.
Źródło:
Journal of Medical Informatics & Technologies; 2007, 11; 41-45
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł

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