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Wyszukujesz frazę "open water" wg kryterium: Temat


Tytuł:
Manoeuvring forces on azimuthing podded propulsor model
Autorzy:
Reichel, M.
Powiązania:
https://bibliotekanauki.pl/articles/260411.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
podded propulsors
open water experiments
manoeuvring forces
Opis:
This paper presents the preliminary part of comprehensive manoeuvring open- water tests of a gas carrier model. The paper focuses on open water experiments with an azimuthing podded propulsor. The test program was carried out in the cavitation tunnel and the large towing tank of Ship Hydromechanics Division, Ship Design and Research Centre, Gdańsk. The pod was tested as a pushing unit with a 161.3 mm diameter propeller. Steering forces were measured in the range of advance coefficient from 0.0 to 0.8 combined with the range of deflection angles from -45° up to +45°. Measurements on the pod without propeller were also performed. The experiment results are presented in the form of non-dimensional coefficients in function of advance coefficient and deflection angle. Analysis of the experimental results and the conclusions are presented.
Źródło:
Polish Maritime Research; 2007, 2; 3-8
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Practical measurement of trajectory in open water model tests
Autorzy:
Michałowski, P.
Wolniak, J.
Powiązania:
https://bibliotekanauki.pl/articles/259497.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
open water model tests
GPS
practical measurements
trajectory
Opis:
The common GPS technology – used at sea or in motor vehicle traffic - does not meet the measurement quality requirements of the present day model tests. It is necessary to use special receivers performing very precise real time measurements. Specialised microprocessor controllers allow to substitute a fallible and inaccurate ship model operator by computers. They guarantee practical execution of precisely defined tasks and their full repeatability. Owing to the coordination of the GPS geodesic technology, computing power of the present day miniature processors and radio communications - test automation, unmanned models, quick analysis of results and control from shore have become feasible.
Źródło:
Polish Maritime Research; 2007, S 2; 42-48
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical validation of the improved vortex method applied to CP745 marine propeller model
Autorzy:
Król, P.
Tesch, K.
Powiązania:
https://bibliotekanauki.pl/articles/259513.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine propeller
open water tests
experiment
lifting surface
CFD
Opis:
The article presents a numerical analysis of the CP745 marine propeller model by means of the improved vortex method and CFD simulations. Both numerical approaches are validated experimentally by comparing with open water characteristics of the propeller. The introduced modification of the vortex method couples the lifting surface approach for the propeller blades and the boundary element method for the hub. What is more, a simple algorithm for determination of the propeller induced advance angles is established. The proposed modifications provide better results than the original version of the vortex method. The accuracy of the improved method becomes comparable to CFD predictions, being at the same time a few hundred times faster than CFD.
Źródło:
Polish Maritime Research; 2018, 2; 57-65
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scenarios to reduce evaporation from class A evaporation pan by using windbreaks
Autorzy:
Oribi, Mustafa O.
Abdulkareem, Asraa K.
Powiązania:
https://bibliotekanauki.pl/articles/118708.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
evaporation basin
windbreaks natural
open water bodies
wind speed
Opis:
Evaporation from reservoirs and lakes is an important processes frequently occurring in dry, hot regions such as Iraq. In order to preserve the environment and to reduce the amount of evaporation from open water bodies in this study, simulation was performed to reduce evaporation from evaporation basin class A by using windbreaks natural (Conocarpus trees). Three basic scenarios were made that depended on the values of the atmospheric elements affecting the evaporation process in summer according to the modified Penman equation for the conditions of Iraq, the climate factors are temperature, solar radiation, wind speed, dew point, and the effect of the number of windbreaks and their height was also introduced in sub- scenario. Experiments have shown that the best sub-scenario for all basic scenarios is when the windbreaks are placed in a direct direction to the wind blowing on the evaporation basin in the form of three rows, each row contains three trees where the windbreaks are in case cross and the height of the trees is 100 cm and the distance between each tree and another, and between each row and row 15 × 15 cm, the results of this subscenario recorded the highest rate of evaporation reduction up to 35% of its original value before using windbreaks.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2020, 29, 3; 343-354
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical review of propeller performance scaling methods, based on model experiments and numerical calculations
Autorzy:
Bugalski, T.
Streckwall, H.
Szantyr, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/258844.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller scale effects
open water tests
computational fluid dynamics (CFD)
Opis:
The article presents the results of experimental and numerical investigation of propeller scale effects, undertaken in co-operation of the Hamburg Ship Model Basin (HSVA), Germany, and Ship Design and Research Centre (CTO SA), Poland. The objective of the investigation was to test the adequacy of the methods currently used to account for the propeller scale effect and to develop possible improvement of the methods. HSVA has conducted model experiments in the large cavitation tunnel together with panel method and CFD calculations. CTO SA has performed model experiments in the towing tank, together with lifting surface and CFD calculations. Both institutions have suggested different new approaches to the problem and different new procedures to account for the propeller scale effects. In the article the procedures are presented together with the description of the underlying experimental and theoretical research.
Źródło:
Polish Maritime Research; 2013, 4; 71-79
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A system for the determination of surface water pCO2 in a highly variable environment, exemplified in the Southern Baltic Sea
Autorzy:
Stokowski, M.
Makuch, P.
Rutkowski, K.
Wichorowski, M.
Kulinski, K.
Powiązania:
https://bibliotekanauki.pl/articles/2078920.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
surface water
carbon dioxide
coastal zone
environment change
inorganic carbon
open water
Baltic Sea
Opis:
Measurement of pCO2 in highly dynamic coastal zones such as the southern Baltic Sea presents many challenges. In this study, we designed a system to measure pCO2 and then validated it in a series of laboratory and seagoing tests. The fast response time of the system was shown to provide a better resolution of CO2 system gradients. In the open waters of the Baltic Sea, the accuracy of the pCO2 measurements (±1.3 μatm) met the requirements of the ICOS (±2.0 μatm). In the coastal zone, there was less consistency between pCO2, DIC and pH measurements, suggesting the need to redefine the quality assurance and control requirements for the measurement of pCO2 in dynamic regions.
Źródło:
Oceanologia; 2021, 63, 2; 276-282
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of the ducted propeller and application to a semi-submerged vehicle
Autorzy:
Zou, Jin
Tan, Guoge
Sun, Hanbing
Xu, Jie
Hou, Yongkang
Powiązania:
https://bibliotekanauki.pl/articles/259041.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
open water test
self-propulsion test
ducted propeller
unmanned semi-submerged vehicle
Opis:
The self-propulsion test of underwater vehicles is the key technique for predicting and evaluating the navigation performance of these submersibles. In this study, the numerical simulation of a standard propeller JD7704+Ka4-70 is first presented and the results are compared with experiments to validate the numerical approaches. The reason why the propulsion efficiency of the ducted propeller is higher than that of the conventional propeller is explored. Then, the paper proposes a series of numerical simulations conducted to test the performance of the ducted propeller designed according to the JD7704+Ka4-70 in order to match with the unmanned semi-submerged vehicle (USSV), and the propeller’s open water characteristic curves are obtained. The results show a reasonable agreement with the regression analysis. Afterwards, the numerical simulations focus on a self-propulsion test of the USSV with the designed ducted propeller and the self-propulsion point is obtained. The streamlines through the hull as well as the ducted propellers are clearly obtained, together with the velocity distributions of the propeller plane. The results vividly demonstrate the hydrodynamic performance of the USSV with the designed propellers. In this paper, all the CFD simulations are based on the numerical software, Star-CCM+, and use the Reynolds-averaged Navier‒Stokes (RANS) equations with the shear stress transport (SST) k-omega turbulence model.
Źródło:
Polish Maritime Research; 2020, 2; 19-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A historical review of ship model testing in open waters
Autorzy:
Kastner, S.
Powiązania:
https://bibliotekanauki.pl/articles/258486.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
capsizing of ships
free-running ship model
open water testing
random seaway
Opis:
Specific features of model testing on hydrodynamic ship behaviour will be discussed, in particular with respect to extreme motions in a natural seaway of open waters. Ship model features described are model scale, water tightness, auto - pilot and remote control, data recording, testing procedures and choice of model situations. Wave gauges supported by buoys allowed measuring seaway. Logistics of open water model testing is compared with new procedures in water tanks generating seaway extremes. A short glimpse is given concerning results found with respect to ship capsizing in random seas. Some photographs allow a lively remembrance of early activities in model runs on a lake many decades ago.
Źródło:
Polish Maritime Research; 2007, S 2; 29-32
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sexual reproduction of chydorids (Anomopoda, Chydoridae) as indicator of climate in recent sediments of Lake Aitajärvi, northern Finnish Lapland
Autorzy:
Sarmaja- Korjonen, Kaarina
Powiązania:
https://bibliotekanauki.pl/articles/2026959.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chydorid ephippia
Subfossil Cladocera
climate
length of open-water season
Finnish Lapland
Opis:
The pres ent work is a part of the de vel op ment of a method which uses the rela tive pro por tions of asexu ally and sexually re pro duc ing chy do rid fe males to re con struct the length of the open- water sea son. Sur face sedi ments (5 cm) of Lake Ai tajärvi, north ern Fin nish Lap land, were ex am ined for mod ern and re cent pro por tions of chy do rid cla do ceran ephip pia in sub arc tic cli mate near the pine limit. The to tal chy do rid ephip pium pro por tions (TCE) were stead ily 9.5–9.7% in the Ai tajärvi sedi ment but de clined to 8.4% in the up per most sam ple. The re sult was com pared with the sur face sedi ment TCE from four lakes in south ern Fin land where it var ied be tween 3–6%. It was also com pared with the TCE from two lakes in north ern most Fin nish Lap land above the treeline in very se vere cli mate, where it was 26–30%. These very high val ues sug gest that there might be a thresh old in cli mate con di tions be tween Ai tajärvi and the two north ern most lakes that al ters the re pro duc tion of chy do rids to wards an even more im por tant role of sex ual repro duc tion.
Źródło:
Studia Quaternaria; 2007, 24; 69-72
1641-5558
2300-0384
Pojawia się w:
Studia Quaternaria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of model-scale open-water test uncertainty
Autorzy:
Król, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/32898216.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
uncertainty
propeller open-water test
lifting surface method
model-scale experiment
propulsion
Opis:
Within the frame of CTO’s standard procedure, a propeller open-water test is preceded by a reference measurement, which is taken for a reference propeller model (P356). The results of these measurements are assembled to conduct an open-water test uncertainty analysis. Additional material was gathered from open-water tests that were conducted throughout several research projects on the CP469 model, which is a model of the Nawigator XXI propeller. The latter is a controllable pitch propeller; its pitch was reset before each test repetition. Known procedures for the determination of the open-water test uncertainty do not allow one to extract the manufacture impact directly, without building many models. This factor was addressed with the use of lifting surface calculations. Under certain additional assumptions, these calculations were performed for 100 generic versions of each propeller’s geometry, which were generated by random deviations from the theoretical data within the limits of allowed tolerances. The results of the conducted analyses made it possible to extract separate factors, which were connected to the test’s repeatability, measurement bias and geometry tolerance.
Źródło:
Polish Maritime Research; 2022, 4; 4-11
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrodynamic multidisciplinary optimization of a container ship and its propeller using comprehensive HPSOP code
Autorzy:
Zakerdoost, H.
Ghassemi, H.
Powiązania:
https://bibliotekanauki.pl/articles/135637.pdf
Data publikacji:
2018
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
hydrodynamic optimization
marine propeller
container ship
hull resistance
ship industry
open water efficiency
Opis:
Hydrodynamic shape optimization plays an increasingly important role in the shipping industry. To optimize ship hull and propeller shapes for minimum total (friction+wave) calm-water resistance and maximum open water efficiency, respectively, the main particulars of a hull and propeller model are considered as design variables. The optimization problem is performed by using an integrated hull-propeller system optimization problem (HPSOP) code in a multi-level and multi-point methodology in early-stage ship design. Three numerical methods with variable fidelity are employed to carry out the hydrodynamic performance analysis of a ship’s hull and propeller. A ship and its propeller are selected as initial models to illustrate the effectiveness of the proposed optimization procedure. The numerical results show that the developed technique is efficient and robust for hydrodynamic design problems.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2018, 53 (125); 48-56
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Annual cycle of phytoplankton community through the water column: Study applied to the implementation of bivalve offshore aquaculture in the Southeastern Bay of Biscay
Autorzy:
Muniz, O.
Revilla, M.
Rodriguez, J.G.
Laza-Martinez, A.
Fontan, A.
Powiązania:
https://bibliotekanauki.pl/articles/47941.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton community
water column
open water
bivalve
biomass
chlorophyll a
nutrient
hydrographic condition
environmental variability
Biscay Bay
Źródło:
Oceanologia; 2019, 61, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydraulic Loss Coefficients in 1D Flows
Autorzy:
Sawicki, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/241418.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
hydraulic loss
closed-conduits flows
water hammer
open channel flow
Opis:
Determination of hydraulic losses is a very important problem, both from the cognitive and practical points of view. For the uniform and steady fluid streams these losses are described by the well known algebraic expressions, containing some experimental coefficients. In technical practice it is commonly assumed, that these coefficients can be applied also for more complex kinds of flow (non-uniform and even unsteady). However, the problem analysis shows that the proper level of conformity between the results of calculations and measurements can be obtained only after a considerable enlargement of the loss coefficient. Investigation of available characteristics of non-uniform and unsteady 1D velocity fields, presented in this article, leads to the conclusion that this enlargement is physically justified and in some cases it is possible to determine correction factors, which enable recalculation of "basic" coefficients into their new values, suitable for more complex models of 1D flows.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2007, 54, 2; 95-116
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane problemy związane z rekultywacją wyrobisk w kierunku wodnym
Selected problems connected with water reclamation of post-mining open-pits
Autorzy:
Różkowski, K.
Polak, K.
Cała, M.
Powiązania:
https://bibliotekanauki.pl/articles/349897.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
górnictwo odkrywkowe
węgiel brunatny
rekultywacja wodna
open-pit mining
lignite
water reclamation
Opis:
Rekultywacja obszarów pogórniczych jest skomplikowanym procesem przywracania zdegradowanych obszarów naturze. Umiejętnie przeprowadzona może w długoterminowej perspektywie odtworzyć pierwotne warunki. Co więcej może wzbogacić środowisko przyrodnicze, podnosząc walory krajobrazowe i zwiększając bioróżnorodność. Wymienione potencjalne korzyści niesie ze sobą rekultywacja w kierunku wodnym, szczególnie w obszarach o ubogiej sieci rzecznej. Tworzenie wielofunkcyjnego zbiornika wodnego jest też pożądane przez lokalną społeczność. Niniejszy artykuł przybliża niektóre problemy związane z geośrodowiskowymi uwarunkowaniami procesu rekultywacji w kierunku wodnym.
Reclamation of post mining areas is a complicated process of restore degraded areas to natural environment. Correctly leading of this process in long time perspective restore the natural conditions. Moreover it enriches the natural environment, improves landscape quality and biodiversity. These potential advantages could be realised by water reclamation especially on areas where hydrographic network is not well developed. Multifunction reservoirs are also expected by local society. Selected problems connected with environmental conditions of water reclamation are focused in the paper.
Źródło:
Górnictwo i Geoinżynieria; 2010, 34, 4; 517-525
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of the Inundation of the Potassium Open Pit in Kalush on the Environment - Predictions and Facts
Wpływ zatopienia kopalni soli potasowej w Kałuszu na środowisko - prognozy i fakty
Autorzy:
Gajdin, A. M.
Maciaszek, J.
Szewczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/385799.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
kopalnia soli w Kałuszu (Ukraina)
solanka
deformacje
open pit in Kalush (Ukraine)
brine water
deformation
Opis:
W artykule przedstawiono badania czynników wpływających na kształtowanie się składu chemicznego wody po zatopieniu odkrywki w ukraińskim mieście Kałusz (obwód iwanofrankiwski). Stwierdzono, że zniszczenia skarp odkrywki, jej brzegów oraz dna jeziora powodują izolację warstw solnych od wody; eliminuje to destrukcyjny wpływ mineralizacji wody wskutek rozpuszczania soli na stateczność brzegów jeziora.
Factors generated chemical composition of water during the influence of the potassium open pit near the city of Kalush, Ivano-Frankiv region were investigated. It was stated that the destruction of the open pit edges, the beach and the bottom of the lake are isolated from salt deposition. The elimination of water mineralization takes place.
Źródło:
Geomatics and Environmental Engineering; 2014, 8, 4; 15-24
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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