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Wyszukujesz frazę "pressure characteristics" wg kryterium: Temat


Wyświetlanie 1-13 z 13
Tytuł:
Experiment on pressure characteristics of submerged floating tunnel with different section types under wave condition
Autorzy:
Li, Q.
Jiang, S.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/260098.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
submerged floating tunnel
section type
irregular waves
pressure characteristics
physical test
Opis:
Submerged floating tunnel (SFT for short) is a special underwater traffic structure, and wave load is one of the main environmental loads of SFT structure. In this paper, the 1:60 physical model test of three kinds of SFT in a two-dimensional wave flume is tested. The effects of random irregular waves on the SFT structure under different wave heights and periods are discussed. The study shows that: (1) Compared with circular and polygonal sections, there are multiple local peaks in the elliptical section during the period. with the increase of wave height, the number of local peaks also increases. It suggests that the rotational moment plays an important role in the elliptical section which has a relatively small depth-width ratio. (2) The position of the maximum and minimum pressure in the three kinds of SFT sections is consistent. Their vertical wave forces are all larger than their horizontal wave forces. The increase of vertical wave force relative to horizontal wave force in polygon section is larger than that in elliptical section, and the difference in the circular section is the smallest. (3) Under the same traffic condition, the wave force of the elliptical and polygon section is smaller, but they are more sensitive to the change of wave height, and the increase is obvious. The distribution of wave force in the circular section is more uniform.
Źródło:
Polish Maritime Research; 2018, S 3; 54-60
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of dynamic characteristics of an experimental bench of high-pressure water fracturing assisted cutting
Autorzy:
Liu, Zhiming
Zhang, Qiang
Sun, Yuliang
Liu, Junming
Powiązania:
https://bibliotekanauki.pl/articles/2200892.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
high-pressure water fracturing
experimental bench
dynamic characteristics
Opis:
Aiming at the problem that the cutting efficiency of a drum shearer is low when mining hard coal seams, an experimental bench of high-pressure water fracturing assisted cutting is designed. Compared with normal ones, the maximum equivalent stress of the improved experimental bench is reduced by 55.38%, and the maximum total deformation is reduced by 27.23%. According to the results of dynamic response analysis, it is concluded that the experimental bench of high-pressure water fracturing assisted cutting is stable and reliable under extreme working conditions, and meets design requirements for strength and stiffness.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 317--330
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the hydrodynamic characteristics of the accelerating and decelerating ducted propeller
Autorzy:
Razaghian, A. H.
Ghassemi, H.
Powiązania:
https://bibliotekanauki.pl/articles/135301.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
accelerating and decelerating ducted propeller
pressure coefficient
hydrodynamics characteristics
Opis:
This paper investigates the open-water characteristics of the 5-blade propeller with accelerating and decelerating ducts using the Reynolds-Averaged Navier-Stokes (RANS) equation code. In the first step, numerical open-water hydrodynamic characteristics of the propeller in the absence of a duct were validated using the available experimental data. The shear stress transport (SST) turbulence model was chosen, which shows less error in thrust and torque coefficients than others. In the second step, two accelerating and decelerating ducts, namely ducts 19A and N32, were modeled. In these simulations, the clearance value was selected at 3 percent of the propeller’s diameter and uniform-flow conditions were assumed. After analysis of the mesh sensitivity for the propeller thrust, the results were compared to the corresponding open-water condition values. In this regard, results of the hydrodynamic coefficients, pressure distribution, and coefficients on the propeller-blade surface and ducts were also analyzed and discussed.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 47 (119); 42-53
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of dense-phase pneumatic conveying in vertical pipe for gasifier
Autorzy:
Gao, Yuzhen
Chan, Choon Kit
Powiązania:
https://bibliotekanauki.pl/articles/27315652.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Pneumatic conveying
Flow characteristics
Dense phase
High pressure
Process innovation
Opis:
The stable transportation of pulverized coal in the vertical pipe is significant for the operation of the gasifier. There are few studies on the flow characteristics and flow pattern transition of particles in vertical pipes with small diameters. This paper has modeled and analyzed the flow characteristic of powder in dense-phase pneumatic conveying through 25 mm vertical pipe using CFD. Firstly, the grid independence is verified to determine the optimal mesh size. Then, the influences of different solid loading ratios (SLRs) and conveying velocities on particle flow characteristics, flow stability, and flow pattern transition are investigated. The results show that the flow pattern in the vertical pipe changes from annular flow to uniform flow at high SLR and low conveying velocity. Moreover, the evolution regulation of resistance characteristics under different conveying velocities is further revealed. Considering the conveying stability and economic benefit, the most suitable conveying velocity is 6 m/s
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 3; 14--22
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic potential of passableness of the agricultural traction-transport technological machine with a hydrodrive of wheels
Metodyka oceny wlasciwosci uciagowych maszyny rolniczej z hydrostatycznym napedem kol jezdnych
Autorzy:
Tajanowskij, G.
Tanas, W.
Powiązania:
https://bibliotekanauki.pl/articles/792965.pdf
Data publikacji:
2011
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
agricultural machine
hydrostatic drive
stress distribution
drawing characteristics
dynamic characteristics
drive wheel
working pressure
wheel slip
velocity
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:
Acquisition of diagnostic information from the indicator diagrams of marine engines using the electronic indicators
Autorzy:
Polanowski, S.
Pawletko, R.
Powiązania:
https://bibliotekanauki.pl/articles/246036.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
marine engines
engine indication
angular axis
pressure sensors
TDC
heat release characteristics
Opis:
The paper analyzes the factors influencing the quantity and quality of diagnostic information obtained by engine indication with electronic indicators and pressures analyzers. Amount of information obtained virtually unchanged since the advent of the first construction pressure analyzers produced by Autronica and ABB Company. In many cases, the value of the maximum combustion and compression pressures, can be measured using these devices with sufficient accuracy and reliability, is if ignition occurs after piston TDC. Determination of the mean indicated pressure, compression ratio and heat release characteristics required to develop a method of TDC determination on the indicator diagrams, generate reliable angular axes in real time and pressure sensors of sufficient accuracy. It should be noted that in the latest solution of ABB system, a correction of thermodynamic loss angle and combustion pressure sensors of high accuracy were introduced. For marine diesel engines diagnosis, the pressure sensor measuring sustainability is important because of the ability to create trends of specific diagnostic parameters, which may constitute an additional, important source of diagnostic information. The paper presents an overview of currently available pressure sensors that can be used during marine engines indication. Most important issues related to the pressure measurement on indicator valves were characterized. An assessment of the gas channels and the quality of the angular axis impact for the parameters of indicator graphs was done.
Źródło:
Journal of KONES; 2011, 18, 3; 359-366
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Glass microspheres thermo-deformation sintering processes in the technologies of obtaining materials for underwater technical equipment
Autorzy:
Kazymyrenko, Yuliia
Solomoniuk, Natalya
Drozd, Oxana
Powiązania:
https://bibliotekanauki.pl/articles/34607483.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
temperature
pressing pressure
structure
porosity
sphericity
subsea equipment
infrastructure characteristics
fiberglass composite
Opis:
In this work, the important scientific and technical problem of creating multifunctional composite materials for shipbuilding and ocean engineering was solved. The work aimed to study the thermal deformation processes of sintering glass microspheres to obtain lightweight glass composites with a cellular structure that provides positive buoyancy and sound insulation properties. For this purpose, glass microspheres of Na2O‒SiO2 and Na2O‒B2O3‒SiO2 composition with a dispersion of 10 to 60 μm were used as raw materials. They were sintered to form a closed, porous structure. The theoretical substantiation of technological parameters is based on the concepts of solid state and glassy state chemistry and physicochemical concepts of glass softening processes. The process of hot-pressing glass microspheres without plasticisers and additives was investigated. The author’s own laboratory equipment was used for the experiments. The sintering intensity was determined from the results of shrinkage processes; the kinetic shrinkage curves were constructed in semilogarithmic coordinates. The glass composite samples were examined by optical and electron microscopy. As a criterion, the storage of spherical microspheres under the influence of simultaneous heating to 700 °C with the application of pressure in the range of 0,5 to 1,5 MPa was chosen. It was established that the formation of a predominantly closed-porous structure of glass composites with a density of 350...600 kg/m3 occurs by the mechanisms of viscous glass phase flow through liquefaction processes in the walls of microspheres. At the same time, shrinkage processes in the linear direction reach up to 50%. The acoustic properties were investigated by measuring the differences in sound pressure levels in octave frequency bands using a Kundt pipe. The water absorption of the glass composite samples was determined at hydrostatic pressures up to 20 MPa. The research results were compared with the characteristics of analogue composites, such as syntactic foams and foam glass. The developed materials can be used in the design and manufacture of technical equipment for research and maintenance of underwater infrastructure. The prospects for further research are related to the feasibility study and marketing research on implementing the developed glass composites.
Źródło:
Polish Maritime Research; 2023, 3; 174-180
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometric characteristics of triticale grain stored under silo pressure
Wplyw naciskow w silosie na zmiany cech geometrycznych pszenzyta
Autorzy:
Guz, T.
Kobus, Z.
Kusinska, E.
Nadulski, R.
Powiązania:
https://bibliotekanauki.pl/articles/793095.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
geometrical characteristics
triticale grain
grain storage
silo
pressure
moisture content
stress value
analysis
storage condition
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 1
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary investigation to estimate soil NAPL retention using parametric pedotransfer functions
Autorzy:
Hernadi, H.
Mako, A.
Powiązania:
https://bibliotekanauki.pl/articles/24805.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
pressure-saturation relationship
soil property
soil
non-aqueous phase liquid
retention
pedotransfer function
hydraulic characteristics
van Genuchten method
Opis:
Organic liquid retention of soils is a primary input variable for modelling the nonaqueous phase liquid transport and behaviour in the subsurface. In environmental and soil physical practice, it is mainly determined by scaling based on the water retention of soils or with charts of average empirical values of organic liquid retention or the fitting parameters of hydraulic functions. Predicting the fitting parameters of organic liquid retention curves with pedotransfer functions might be a promising alternative method, but this topic has only been researched to a limited extent. Thus we investigated the applicability of different hydraulic functions (3- and 4- parameter form of the van Genuchten equation and Brutsaert equation) for fitting organic liquid retention characteristics. Multivariate linear regression was used to build and develop pedotransfer functions, modelling relations between original and transformed values of basic soil properties and organic liquid retention. We attempted to generate parametric pedotransfer functions. According to our results, the applicability of hydraulic functions for fitting nonaqueous phase liquid retention curves to the experimental data was proven. The investigations gave promising results for the possibility to estimate soil nonaqueous phase liquid retention with parametric pedotransfer functions.
Źródło:
International Agrophysics; 2014, 28, 4
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some effects of wind on ship’s manoeuvrability
Autorzy:
Szymoński, M.
Powiązania:
https://bibliotekanauki.pl/articles/117192.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
ship’s manoeuvrability
effects of wind
wind resistance
wind speed
windage area
wind pressure force
manoeuvring characteristics
dynamic parameters
Opis:
All ships experience an air and wind resistance while under way of sea, and they may experience adverse effects on wind while manoeuvring in harbours and limited waterways. The wind resistance is proportional to relative wind speed squared, wind direction and the projected windage area of the ship. The paper describes the effect of wind pressure into the ship’s superstructures and houses on ship manoeuvrability, in the range of the wind speed, for the ship which is with the large windage area. The above is one of the recommended information to be included in the ship’s manoeuvring booklet, as per IMO Resolution A.601(15). In sea practice, the manoeuvring characteristics in wind, as wind forces and moments, course-keeping limitation, and drifting under wind influence are fare from these estimated. The results obtained during the several years of practice in ship’s exploitation are included in this paper.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 3; 623-626
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An examination of vehicles at the brake-chassis test bed in the range of the partial engine load.
Autorzy:
Marzec, P.
Powiązania:
https://bibliotekanauki.pl/articles/196586.pdf
Data publikacji:
2017
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
partial load of the engine
external characteristics of the engine
indicated pressure
częściowe obciążenie silnika
zewnętrzne właściwości silnika
wskazane ciśnienie
Opis:
The performance of a ZI engine is presented in the paper, as well as a project involving a device for applying a partial load in the performed examinations of a brake-chassis test bed. The device was prepared for an Opel Astra and enabled the determination of exterior characteristics of the engine for different values of the engine load. The indicating pressure sensor and the angle marker on the crankshaft allowed for the recording of the indicating pressure obtained at different values of the load. The analysis of heat evolution in the process of burning, based on the registered results of the measurements at the brake-chassis test bed, has also been included in the presentation.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2017, 95; 121-131
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Minimum Pressure Drop Caused by the Condensation of Water Vapor in the Cooled Air Flowing in the Inclined Conduit
Minimalna strata ciśnienia spowodowana kondensacją pary wodnej w chłodzonym powietrzu płynącym przewodem nachylonym
Autorzy:
Ptaszyński, Bogusław
Kuczera, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/318286.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
dwufazowy przepływ bezpoślizgowy
strata ciśnienia
charakterystyka przewodu
masowe źródła wody z kondensacji pary wodnej
two-phase no-slip flow
pressure loss
flow characteristics of a duct
water mass sources from water vapor condensation
Opis:
The paper presents methodology for determining water mass and pressure drop in ducts with fixed co-current and no-slip two-phase flow. The dispersed liquid phase (water) is present in the air as a result of wet air from underground excavations being distributed in some sections of a discharge pathway, or local water mass sources (or its local outlets) formed by the natural phenomenon of water vapor condensation. For such cases, static pressure losses were determined, which resulted from the force of gravity of the mass of water droplets occurring in the air stream in the duct.
W pracy przedstawiono metodologię wyznaczania masy wody i spadku ciśnienia w przewodach z ustalonym współprądowym bezpoślizgowym przepływem dwufazowym. Zdyspergowana faza ciekła (woda) występuje w powietrzu w wyniku ochłodzenia strumienia wilgotnego powietrza na niektórych odcinkach drogi jego odprowadzenia z wyrobisk podziemnych lub w miejscach występowania lokalnych źródeł masy wody (lub jej lokalnych upustów) utworzonych przez naturalne zjawisko kondensacji pary wodnej przy mieszaniu się strumieni powietrza wilgotnego. Dla takich przypadków określono straty ciśnienia statycznego, które wynikały z siły grawitacji masy kropelek wody występujących w strumieniu powietrza w szybie wydechowym.
Źródło:
Inżynieria Mineralna; 2019, 21, 1/2; 189-197
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of pressure loss in steerable tyre wheel on steerability of four-axle special purpose vehicle
Wpływ utraty ciśnienia w ogumieniu koła kierowanego na kierowalność czteroosiowego pojazdu specjalnego
Autorzy:
Stryjek, P.
Motrycz, G.
Pieniążek, W.
Powiązania:
https://bibliotekanauki.pl/articles/347148.pdf
Data publikacji:
2013
Wydawca:
Akademia Wojsk Lądowych imienia generała Tadeusza Kościuszki
Tematy:
AFVs
tires
pressure
damage
steady state circular test
steerability characteristics
double lane change
loss of lateral stability
transportery opancerzone
opony
ciśnienie
uszkodzenia
ustalona jazda po okręgu
podwójna zmiana pasa ruchu
charakterystyka kierowalności
utrata stateczności poprzecznej
Opis:
The authors of this paper took a part in a government research project on the behavior of a military AFV after an explosive damage to its tires, which inter alia aims to assess its motion-al abilities, also in terms of ensuring the safety of the crew. The results presented hereto refer to a part of preliminary experimental studies on a four-axle vehicle with a total weight of 22,000 kg and a length of 8m, carried out in the situations of a substantial or complete loss of tire pressure in the first steerable wheels axle. A significant influence of the total pressure loss in the drivability of the vehicle has been proven.
Autorzy niniejszej pracy uczestniczyli w rządowym projekcie badawczym dotyczącym problemu zachowania się transportera wojskowego po eksplozyjnym uszkodzeniu ogumienia, który miał na celu, między innymi, ocenę jego możliwości ruchowych, w aspekcie zapewnienia bezpieczeństwa załogi. Przedstawione wyniki dotyczą fragmentu wstępnych badań eksperymentalnych pojazdu czteroosiowego o masie całkowitej 22.000 kg i długości 8m, przeprowadzonych w sytuacjach znacznej lub całkowitej utraty ciśnienia w ogumieniu koła pierwszej osi kierowanej. Wykazano znaczny wpływ całkowitej utraty ciśnienia na kierowalność pojazdu.
Źródło:
Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki; 2013, 4; 92-100
1731-8157
Pojawia się w:
Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-13 z 13

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