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Search results for: COOLING RATE
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Nonlinear impedance of annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of annealed and next fully crystallized 50Bi2VO5.5-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 fully crystallized glass at 813 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 40Bi2VO5.5-60SrB4O7 annealed glass at 593 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of 40Bi2VO5.5-60SrB4O7 glass annealed at 593 K was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 partially crystallized glass at 613 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 partially crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance as a function of A.C. voltage for fully crystallized 45Bi2VO5.5-55SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties as a function of A.C. voltage for fully crystallized 45Bi2VO5.5-55SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 30Bi2VO5.5-70SrB4O7 fully crystallized glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 30Bi2VO5.5-70SrB4O7 fully crystallized glass was measured by impedance spectroscopy method.
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Nonlinear impedance of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of glass 40Bi2VO5.5-60SrB4O7 annealed at 593 K and next fully crystallized was measured by impedance spectroscopy method.
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The topography of as-quenched and heat treated 50(2Bi2O3-V2O5)-50SrB4O7 and 50Bi2VO5.5-50SrB4O7 glasses measured with confocal microscope
Open Research DataThe topography of as-quenched and heat treated 50(2Bi2O3-V2O5)-50SrB4O7 and 50Bi2VO5.5-50SrB4O7 glasses measured with confocal microscope.
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The topography of as-quenched and heat treated 50(2Bi2O3-V2O5)-50SrB4O7 and 50Bi2VO5.5-50SrB4O7 glasses measured with AFM
Open Research DataThe topography of as-quenched and heat treated 50(2Bi2O3-V2O5)-50SrB4O7 and 50Bi2VO5.5-50SrB4O7 glasses measured with AFM.
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The structure of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. measured with X-ray diffraction method
Open Research DataThe structure of strontium–borate glasses and glass-ceramics containing Bi2VO5.5 nanocrystallites was measured by XRD.
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Improvement of the thrust bearing calculation considering the convectional heating within the space between the pads
PublicationA modern thrust bearing calculation tool should consider not only the oil film between pad and rotating collar but also the space between the pads. The oil flow in the space has a significant influence on the oil film inlet temperature, the convectional cooling of pad and collar and should be included in the bearing calculation methods. The authors use a tool developed at Clausthal University of Technology in cooperation with the...
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Beyond the helium buffer: 12C−2 rotational cooling in cold traps with H2 as a partner gas: interaction forces and quantum dynamics
Publicationabstract = { The scattering cross-sections and corresponding rate coefficients for rotationally inelastic collisions of $^{12}$C$_2$^-$ ($^2 \Sigma_g^+$) with H$_2$ ($^1 \Sigma_g^+$) are presented over a broad range of cold-trap temperatures. They have been calculated using quantum scattering theory that employs a new ab initio potential energy surface. The rate coefficients for the inelastic processes in the anionic partner are...
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Experimental Investigation of the Thermal Performance of a Wickless Heat Pipe Operating with Different Fluids: Water, Ethanol, and SES36. Analysis of Influences of Instability Processes at Working Operation Parameters
PublicationIn this study, the influences of different parameters on performance of a wickless heat pipe have been presented. Experiments have been carried out for an input power range from 50 W to 300 W, constant cooling water mass flow rate of 0.01 kg/s, and constant temperature at the inlet to condenser of 10 C. Three working fluids have been tested: water, ethanol, and SES36 (1,1,1,3,3-Pentafluorobutane) with different filling ratios (0.32,...
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Prognozowanie właściwości złączy spawanych pod wodą metodą lokalnej komory suchej
PublicationNiniejsza praca jest poświęcona spawaniu pod wodą metodą lokalnej komory suchej (MLKS) i przedstawia metodologię oraz narzędzia umożliwiające prognozowanie właściwości złączy spawanych wykonanych przy zastosowaniu tej odmiany spawania. Monografia zawiera opis rozwoju spawania pod wodą oraz charakterystykę metod wykorzystywanych do realizacji prac spawalniczych. Zaproponowano nowy podział metod spawania pod wodą, uwzględniający...
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The topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. measured with SEM method
Open Research DataThe topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. was measured by SEM.
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Active management of equipment cooling in hoteling data centers
PublicationHoteling data centers are designated for housing computing and storage units of many, usually small customers, as opposed to traditional data centers supporting own computing and storage resources of a bigger company. One of the services to be provided to consumer’s equipment is cooling. Cooling in data centers is prevalently achieved by circulating air in computer room. Efficient cooling requires delivering cold air from central...
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THERMAL ANALYSIS AND DESIGN OF HYBRID MICROCHANNEL -MICROJET TEST PROBE
PublicationAccurate control of cooling parameters is required in ever wider range of technical applications. It is known that reducing the flow hydraulic diameter to an increase in the economy of cooling and improves its quality (Mikielewicz and Muszyński 2009). Present study describes research results related to the design and construction of the test stand for hybrid microjet- microchannel cooling modules study, which may be applied in...
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Heat exchange enhancement of jet impingement cooling with the novel humped-cone heat sink
PublicationJet impingement cooling technology is applicable to control temperature of devices, where very high heat flux is generated within a small area. This paper is about the improvement of the jet impingement cooling efficiency by the heat sink geometry modification. Two reference cases were sourced from the literature – flat heat sink and modified one with cone in the jet stagnation region. Such a change improves cooling capability...
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Heat transfer characteristics of hybrid microjet – Microchannel cooling module
PublicationThe paper presents experimental investigation of heat transfer intensification in a microjet–microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was...
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The structure of strontium–borate glass-ceramics containing crystalites of Bi2VO5.5. measured with X-ray diffraction and SEM methods
Open Research DataThe structure of strontium–borate glass-ceramics containing Bi2VO5.5 crystallites was measured by XRD and SEM.
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Heat transfer characteristics of hybrid microjet -microchannel cooling module
PublicationThe paper presents the experimental investigation of heat transfer intensification in a microjet- microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper...
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Influence of external walls' thermal capacitance on indoor thermal comfort
PublicationThe doctoral thesis presents the results of numerical investigations on the influence of walls’ thermal capacitance on indoor thermal comfort. A proper set of thermal parameters of a building structure can considerably limit the heating / cooling demand, and passively increase the indoor thermal comfort. However the effect of building thermal capacitance on indoor conditions is complex and not always beneficial. Among a great number...
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Flow visualization and heat transfer investigations on the flat plate with streamwise pressure gradient
PublicationPaper presents experimental investigations results for film cooling on a flat plate. The main objective of the design is the streamwise pressure distribution on the flat plate as in the blade cascade. The transient and steady-state technique with liquid crystals for the surface temperature distribution with film cooling has been used in experiments in a low speed wind tunnel.
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Determination of t8/5 cooling times for underwater local dry welding of steel
PublicationKnowledge of thermal history is the basic condition for studying the structure - properties of welded joints. The determinant of thermal history is the thermal cycle, whose in-situ measurements are still a big challenge. Water as the welding environment complicates this issue even more. The article presents a method to determine an equation for calculating t8/5 cooling times for underwater gas metal arc welding of unalloyed steels...
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Simplified method of water cooled exhaust system design.
PublicationThe water cooled exhaust systems are not often used onboard ships. Prime goal is to lower temperature of exhaust gas from main propulsion and auxiliary engines to the defined limit. The design of such systems require detailed analysis of propulsion system operational parameters to meet designer expectations. The paper outlines the cooled exhaust system design problems in specific application. The simplified method of evaluation...
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of 50(Bi2VO5.5)-50SrB4O7 glass was measured by impedance spectroscopy method.
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Modeling of the internal combustion engine cooling system
PublicationThe article concerns computer modelling of processes in cooling systems of internal combustion engines. Modelling objectives and existing commercial programs are presented. It also describes Author’s own method of binding graphs used to describe phenomena in the cooling system of a spark ignition engine. The own model has been verified by tests on the engine dynamometer. An example of using a commercial program for experimental...
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Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
PublicationEnergy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed...
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A study of jet impingement cooling enhancement by concave and convex heat sink shape modifications
PublicationThe rising demand for efficient cooling technologies is a strong driver of extensive research in this area. This trend is particularly strong in turbines and microprocessors technology. Presented study is focused on the jet impingement cooling concept, which is used in various configurations for many years. The potential of the heat sink shape modification is not yet fully explored. Available literature suggests that average Nusselt...
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A System for Cooling Electronic Elements with EHD Coolant Flow
PublicationA system for cooling electronic components where the liquid coolant flow is forced with ion-drag type EHD micropumps was tested.
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Friction and Lubrication of Large Tilting-Pad Thrust Bearings
PublicationFluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due...
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Propagation of initially sawtooth periodic and impulsive signals in a quasi-isentropic magnetic gas
PublicationThe characteristics of propagation of sawtooth periodic and impulsive signals at a transducer are analytically studied in this work. A plasma under consideration is motionless and uniform at equilibrium, and its perturbations are described by a system of ideal magnetohydrodynamic equations. Some generic heating/cooling function, which in turn depends on equilibrium thermodynamic parameters, may destroy adiabaticity of a flow and...
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The effect of laser on metal surfaces for multidisciplinary usage in material and thermal engineering
PublicationThe subject of heat transfer and cooling systems is still a matter of contention in many different fields of science and industry. Infrigidation is much more difficult than warming, and so, much more needed in more and more different devices, starting from massive industrial machinery and air conditioning in commercial buildings, up to micro and nano-surgery tools. In fact, the size of many cooling systems is still a problem. It...
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Interaction of Acoustic and Thermal Modes in the Vibrationally Relaxing Gases. Acoustic Cooling
PublicationThe dynamic equation which governs an excess temperature associated with the thermal mode in vibrationally relaxing gas is derived. The nonlinear transfer of acoustic energy to the energy of the thermal mode in a relaxing gas causes slow variation of temperature with time. The nal dynamic equation is instantaneous. All types of sound, including aperiodic, may be considered as an acoustic source of corresponding heating or cooling....
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Inlet air fogging of marine gas turbine in power output loss compensation
PublicationThe use of inlet air fogging installation to boost the power for gas turbine engines is widely applied in the power generation sector. The application of fogging to mechanical drive is rarely considered in the literature [1]. This paper will cover some considerations relating to its application to gas turbines in ship drive. There is an important evaporative cooling potential throughout the world when the dynamic data is evaluated,...
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Experimental investigation on heat pipes supported by soy wax and lauric acid for electronics cooling
PublicationThis paper presents an experimental study of heat pipes for electronics cooling that were supported by energy storage materials (i.e. phase change materials - PCMs) coated at the adiabatic section. The PCMs utilized included two materials, namely lauric acid and soy wax, the latter being considered as a more cost-effective alternative. The study focused on three different powers: 20 W, 25 W, and 30 W. Both heating, cooling, and...
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COMPARISON OF HEAT TRANSFER CHARACTERISTICS IN SURFACE COOLING WITH BOILING MICROJETS OF WATER, ETHANOL AND HFE7100
PublicationThe basis of microjet technology is to produce laminar jets which when impinging the surface have a very high kinetic energy at the stagnation point. Boundary layer is not formed in those conditions, while the area of film cooling has a very high turbulence resulting from a very high heat transfer coefficient. Applied technology of jet production can result with the size of jets ranging from 20 to 500μm in breadth and 20 to 100μm...
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation into the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. Experiments were conducted using the nozzle size of 70 and 100 mikrometer respectively. In the course of investigations obtained were experimental relations between heat flux and wall superheating. It was proved that the phenomenon is similar to that of pool boiling...
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Performance of a hybrid microjet – microchannel cooling module
PublicationThe paper presents the experimental investigation of a microjet- microchannel cooling module. In which microjets of water are impinging into the microchannels and forming a liquid film on the impingement surface. Applied technology takes benefits from two very attractive heat removal techniques. When lminar jets are impinging on the surface have a very high kinetic energy at the stagnation point, also in microchannels boundary...
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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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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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ANALYSIS OF DIESEL OIL SPECIFIC HEAT IMPACT FOR OPERATION OF THE SUPPLY PUMP
PublicationThe article describes a test rig that allows the measurement of fuel oil specific heat changes based on the cooling time of liquids. After that, by analysing the test results, a research hypothesis was created and verified. The hypothesis is that the specific heat energy of fuel oil impact the operation of the circulation pump.
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Thermal ablation modeling via the bioheat equation and its numerical treatment
PublicationThe phenomenon of thermal ablation is described by Pennes’ bioheat equation. This model is based on Newton’s law of cooling. Many approximate methods have been considered because of the importance of this issue. We propose an implicit numerical scheme which has better stability properties than other approaches.
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Quantification of Compatibility Between Polymeric Excipients and Atenolol Using Principal Component Analysis and Hierarchical Cluster Analysis
PublicationAn important challenge to overcome in the solid dosage forms technology is the selection of the most biopharmaceutically efficient polymeric excipients. The excipients can be selected, among others, by compatibility studies since incompatibilities between ingredients of the drug formulations adversely affect their bioavailability, stability, efficacy, and safety. Therefore, new, fast, and reliable methods for detecting incompatibility...
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Improved energy management technique in pipe-embedded wall heating/cooling system in residential buildings
PublicationEffective and environmentally responsive techniques of energy management in residential buildings are desirable for the resulting reduction of energy costs and consumption. In this paper, an improved and efficient technique of energy management in pipe-embedded wall heating/cooling systems, called the Thermal Barrier, is described. Specifically, the Thermal Barrier is a technique focused on the management and control of heat...
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Improved energy management technique in pipe-embedded wall heating/cooling system in residential buildings
PublicationEffective and environmentally responsive techniques of energy management in residential buildings are desirable for the resulting reduction of energy costs and consumption. In this paper, an improved and efficient technique of energy management in pipe-embedded wall heating/cooling systems, called the Thermal Barrier, is described. Specifically, the Thermal Barrier is a technique focused on the management and control of heat supply...
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THERMION-C2S_0301 Phase transition in Cu1.96Se
Open Research DataInvestigation of a phase transition in Cu1.96Se was investigated. The data contains results of thermal analysis (DSC) and thermoelectric properties measurements. These measurements were performed with different heating and cooling rates. Structure and elemental composition were also analysed. The data shows the influence of the kinetics of the transition...
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Resonant and nonresonant excitation of waves in a planar magnetosonic flow
PublicationForced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating-cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical...
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Influence of Holes Manufacture Technology on Perforated Plate Aerodynamics
PublicationTranspiration flow is a very important and still open subject in many technical applications. Perforated walls are useful for the purpose of “flow control”, as well as for the cooling of walls and blades (effusive cooling) in gas turbines. We are still not able to include large numbers of holes in the numerical calculations and therefore we need physical models. Problems are related also to the quality of the holes in perforated...
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Assessment of the impact of jet impingement technique on the energy efficiency of air-cooled BIPV/T roof tile
PublicationThe paper concerns a numerical analysis of cooling of the hybrid photovoltaic (PV) modules dedicated to Building-Integrated Photovoltaic/Thermal (BIPV/T) systems. Attention was focused on the photovoltaic roof tiles, using a jet impingement technique, in which the intensification of heat transfer is ensured by streams of air hitting the heat exchange partition. A series of numerical simulations were carried out to assess an influence...