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Search results for: POOL BOILING
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublicationIn the paper are presented the results of calculations using authors own model to predict heat transfer coefficient during flow boiling for carbon dioxide. The experimental data from various researches were scrutinised conducted for a full range of quality variation and wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The work shows the importance of taking into account surface...
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Non-adiabatic Effects in Pressure Drop Calculations in Flow Boiling and Flow Condensation in Minichannels
PublicationConsiderations presented in the paper relate both to the case of flow boiling and flow condensation in conventional channels as well as small diameter ones. Authors devoted all the possible attention that the modeling presented is applicable to the whole range of quality variation in both cases of condensation and boiling. The form of two-phase flow multiplier, which is a major factor in modeling presented here, should be capable...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublicationThe distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures...
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A simplified energy dissipation based model of heat transfer for post-dryout flow boiling
Publicationmodel for post dryout mist flow heat transfer is presented based on considerations of energy dissipation in the flow. The model is an extension of authors own model developed earlier for saturated and subcooled flow boiling. In the former version of the model the heat transfer coefficient for the liquid singlephase convection as a reference was used, due to the lack of the appropriate model for heat transfer coefficient for the...
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Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels
PublicationDetailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged...
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The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of carbon dioxide. The experimental data from various resea rches were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The results show the importance of taking into...
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Influence of porous coating on heat transfer during flow boiling of R22, R134a and R407C
PublicationPrzedstawiono wpływ pwłoki porowatej w pozionej rurce podczas wrzenia w przepływie i spadku ciśnienia czynników chłodniczych R22, R134a i R407C.
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A semi-empirical model for flow boiling heat transfer with account of the reduced pressure effect
PublicationIn the present study the attention was focused on the influence of reduced pressure on the predictions of heat transfer during flow boiling at the extensive range of pressures. The results of calculations were to test the sensitivity of the in-house flow boiling model with respect to the selection of the appropriate two-phase flow multiplier, which is one of the distinctive elements of that model. For this purpose a few two-phase...
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Flow distribution and heat transfer in minigap and minichannel heat exchangers during flow boiling
PublicationThe topic of boiling heat transfer in miniscale geometries has focused the ever increasing interest of researchers in recent years. However, most of the works are related to mini- and microchannels and much less to minigaps. Meanwhile, minigaps allow for more comprehensive experimental studies, i.e. flow visualisations due to the flat, two-dimensional configuration of the flow. The results of the experimental investigations of...
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Experimental study and comparison with predictive methods for flow boiling heat transfer coefficient of HFE7000
PublicationThis article describes an experimental study of flow boiling of HFE7000 inside a smooth vertical channel. The investigation has been carried out in a circular stainless-steel tube with an inner diameter of 2.3 mm. The data have been collected for the applied heat fluxes q ranging from 61 to 205 kW/m2, the mass flux G ranging from 214 to 1006 kg/(m2 s), the saturation temperature Tsat ranging from 30 to 54 °C and the full range...
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Simulation research on the tool cycle in automated manufacturing system at selected tool duplication levels
PublicationThe paper presents results of the research concerning impact of applied tool exchange rule on the efficiency of an automated manufacturing system. The research consider the tool duplication levels that constrain realisation of a manufacturing process. Presented study was based on the real industrial system data. The operating of the investigated system of manufacture, including tools necessary for its realisation, was modelled...
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Statistical Dynamics of the Rolling Mills
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Location of ship rolling axis.
PublicationPodano definicję osi kołysań statku i metodę określania jej położenia. Położenie osi zależy nie tylko od rozkładu mas statku ale równiez od tzw. ''mas towarzyszących'', które są reprezentacją sił hydrodynamicznych działających na statek w czasie kołysania. Podano proste formuły pozwalajace obliczyć poprawne położenie osi kołysań statku.
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Structures of diamond tool composites
PublicationPresented are structures and examples of applications of diamond tool composites. They are widely used as cutting tools, bonded abrasive tools and dressing tools.
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MutS as a tool for mutation detection.
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Balconies as a tool in buildings rewitalisation.
PublicationW pracy przedstawiono sposób renowacji elewacji budynków połączony z zastosowaniem dodatkowych balkonów. Przedstawino kilka rozwiązań konstrukcyjnych montażu balkonów w istniejących budynkach.
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MutS as a tool for mutation detection
PublicationArtykuł przeglądowy pokazujący różne możliwości zastosowania różnych form białka MutS Thermus thermophilus do wykrywania mutacji punktowych.
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Beijing Gongye Daxue Xuebao / Journal of Beijing University of Technology
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Beijing Jiaotong Daxue Xuebao/Journal of Beijing Jiaotong University
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Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University
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Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology
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The orthogonalization of objects simplified with the Simplify Building tool representing groups of buildings in Kartuzy district - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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A new method for determination of flow boiling heat transfer coefficient in conventional diameter channels and minichannels
PublicationW pracy przedstawiono rozważania związane z modelowaniem wrzenia w przepływie w kanałach o średnicach konwencjonalnych, małych i minikanałach. Przedstawiono przegląd podejść do modelowania wymiany ciepła i w tym świetle przedstawiono oryginalne podejście autora. W przeciwieństwie do innych podejść metoda autora ma zastosowanie zarówno do kanałów o średnicach konwencjonalnych i minikanałach. Przedstawiono zadowalające porównania...
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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A semi-empirical method for calculation of heat transfer coefficient in flow boiling for conventional tubes and minichannels
PublicationW pracy przedstawiono zagadnienia które należy uwzględnić podczas modelowania wymiany ciepła z wrzeniem w przepływie w kanałach o małej średnicy. Uzyskano dobrą zgodność z wynikami badań eksperymentalnych.
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EXPERIMENTAL VERIFICATION OF THE METHOD OF FLOW BOILING AND FLOW CONDENSATION HEAT TRANSFER PREDICTION FOR SELECTED FLUIDS
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of different refrigerants. The experimental data from various research studies from literature were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in- house developed model....
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Calculation method for flow boiling and flow condensation of R134a and R1234yf in conventional and small diameter channels
PublicationThe paper presents the results of calculations performed using the authors’ model to predict the heat transfer coefficient during flow boiling for two refrigerants R134a and R1234yf. The experimental data from various past studies have been collected and the calculations have been conducted for the full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house...
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Influence of wall temperature on heat transfer coefficient during R 22 boiling in microfin tube
PublicationPrzedstawiono wyniki badań współczynnika przejmowania ciepła i spadku ciśnienia podczas wrzenia czynnika R 22 w rurze nisko żebrowanej. Opisano stanowisko i procedurę badawczą. Zaobserwowano spadek współczynnika przejmowania. Opisano stanowisko i procedurę badawczą. Zaobserwowano spadek współczynnika przejmowania ciepła wraz ze wzrostem temperatury ścianki rury.
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A semi-empirical method for calculation of heat transfer coefficient in flow boiling for conventional tubes and minichannels
PublicationW pracy przedstawiono zagadnienia któe należy uwzględnić podczas modelowania wymiany ciepła z wrzeniem w przepływie w kanałach o małej średnicy. Uzyskano dobrą zgodność z wynikami badań eksperymentalnych.
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Effect of asymmetric fluid flow distribution on flow boiling in a microchannel heat sink – An experimental investigation
PublicationFlow boiling in microchannels is emerging as an exclusive cooling solution for miniaturized high-power electronic devices alongside having other high heat flux applications. Size miniaturization at microscale strangely increases heat transfer performance as well as flow boiling instabilities. Many flow boiling instabilities are interrelated and result from imperfect hydrodynamic conditions. One of such problems is flow maldistribution among...
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Flow boiling of R1233zd(E) in a 3 mm vertical tube at moderate and high reduced pressures
PublicationThe results of flow boiling of R1233zd(E) in a 3 mm vertical stainless steel tube are presented at moderate and high saturation temperatures. Integral flow characteristics in the form of pressure drop and heat transfer coefficient are discussed for saturation temperatures ranging from 115 to 145 °C (corresponding reduced pressures from 0.2 to 0.7), mass velocity of 800 kg/m2s and heat flux of 20 kW/m2. All of the obtained heat...
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The generalization of objects representing groups of buildings in the Kartuzy district by simplification operator with the Simplify Building tool - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The orthogonalization of simplified objects representing groups of buildings in Gdańsk district using the Simplify Building tool - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The generalization by simplification operator with the Simplify Building tool of objects representing groups of buildings in Gdańsk district - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The generalization of objects representing groups of buildings in the Kartuzy district by simplification operator with the Simplify Building tool - scale 1:25000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The generalization by simplification operator with the Simplify Building tool of objects representing groups of buildings in Katowice district - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The generalization by simplification operator with the Simplify Building tool of objects representing groups of buildings in Katowice district - scale 1:25000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The generalization by simplification operator with the Simplify Building tool of objects representing groups of buildings in Gdańsk district - scale 1:25000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation in the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. It was proved that the phenomenon is similar to that of pool boiling. Results of experiments were compared with predictions by the model showing a good consistency.
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Dome over the Gdynia seaport building
PublicationThe paper presents the description of structure and the selected problems of the technical condition, as well as the strength analysis of the thin-walled reinforced concrete shell which has been making a covering of the main hall of the Gdynia Seaport Building through the last 80 years. The rectangle projection of four single curvature shells of the dome was shaped out of mutual perpendicular intersection of two cylindrical shells. The...
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Type of surface and tire rolling resistance
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Methods of Tire Rolling Resistance Measurements
PublicationTire rolling resistance is one of the factors related to tire/road interaction that has important influence on road vehicles performance. Raising fuel price and increased concern related to the environmental changes result in growing interest in reduction of tire rolling resistance that influences fuel consumption, especially in free-flowing highway traffic with moderate speeds. There are several methods of tire rolling resistance measurements....
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The Modern Agora for Building the Open Society
Publication• sekretarz naukowo-organizacyjny - organizacja międzynarodowej konferencji “The Modern Agora for Building the Open Society ” we współpracy z Europejskim Centrum Solidarności, 02.06.2015 pod patronatem ISOCARP, International Society of City and Regional Planners orazTowarzystawa Urbanistów Polskich TUP/Gdansk. Przy udziale przedstawicieli następujących uczelni: Politechnika Śląska, Fachhochshule Erfurt/ Germany, Mimar...
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Rolling resistance measurements of studded tires
PublicationW pracy przedstawiono wyniki pomiaru oporu toczenia opon kolcowanych i po usunięciu kolców na nawierzchni poroelastycznej. Badania przeprowadzono na stanowisku bębnowym Katedry Pojazdów i Maszyn Roboczych Politechniki Gdańskiej. Opony kolcowane mają o około 5% wyższy współczynnik oporu toczenia w porównaniu z oponami nie kolcowanymi.
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The new concept of product. Cooling band
PublicationThe chapter below presents the innovative solution consist in applying the cooling band to help holding the hot object. The solution was found through substitute inputs analysis and brain storm method. The new product was submitted in Polish Patent Office under the No. W.120905.
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Polyethylene as a small vessel's building material
PublicationThe most common use of polyethylene we can notice nowadays are areas like water supply systems, gas industry (esp. gas piping), food industry, small-scale, light and consumer goods industries. That material has far more applications. One of them is shipbuilding - especially small inland or offshore vessels.
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Sick building syndrome due to molds
PublicationThe term Sick Building Syndrome (SBS) is a combination of ailments occurring in a specific building. Building occupants complain of symptoms such as headaches and dizziness, fainting, nausea, irritation of the mucosal membranes, skin irritation and other nonspecific hypersensitivity reactions.One of the SBS causes can be molds, which are ubiquitous in the air (over 400 species). It is estimated that 30% of the health problems (related...
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Refurbishment of a historical building - design issues
PublicationOver a 10-year modernization of the main building of Gdansk University of Technology is coming to the end. The ever increasing number of students requires not only the development of the campus with new facility buildings, also the existing buildings are subject to adaptation and modernization. In addition to high-impact solutions, as restoring the former glory of the building (reconstruction of the clock tower), or introducing...
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INFLUENCE OF TEMPERATURE ON THE TYRE ROLLING RESISTANCE
PublicationTemperature is a very important factor controlling rolling resistance of road vehicle tyres. There are at least three different temperatures that may be considered as important factors controlling thermal conditions of the rolling tyre. The most common measure of the thermal conditions during tyre rolling is ambient air temperature. The other two are: pavement temperature and “tyre” temperature. Tyre temperature is the most difficult...