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Wyszukujesz frazę "inverse method" wg kryterium: Temat


Tytuł:
Identification of the Heat Transfer Coefficient at the Charge Surface Heated on the Chamber Furnace
Autorzy:
Gołdasz, A.
Malinowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/356595.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat transfer coefficient
inverse method
finite element method
Opis:
The inverse method was applied to determine the heat flux reaching the charge surface. The inverse solution was based upon finding the minimum of the error norm between the measured and calculated temperatures. The charge temperature field was calculated with the finite element method by solving the heat transfer equation for a square charge made of 15HM steel heated on all its surfaces. On the basis of the mean value of heat flux, the value of the heat transfer coefficient at each surface was determined depending on the surface temperature of the material heated.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 509-513
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the assumed thermophysical properties of steel on the heat transfer calculation result in contact phenomena
Autorzy:
Rywotycki, Marcin
Malinowski, Zbigniew
Przyłucka, Aleksandra
Sołek, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/29520236.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
heat transfer
inverse method
solid surface contact
Opis:
The article presents a model of heat transfer between two solid surfaces remaining in contact under the effect of the force applied. The presented results were obtained from the authors’ own studies conducted with the application of a new method of determining the heat flux transferred between these surfaces. The method consists of two stages: the experiment and numerical calculations. The experimental tests include temperature measurements in specific points in two samples remaining in contact with each other. The numerical part uses the inverse solution and the finite element method for the calculation of the heat flux on the contact surface. An analysis was performed on the effect of the steel grade used in the tests on the result of heat transfer determination in contact phenomena. The calculations were conducted with the application of proprietary software using the inverse method integrated with FEM.
Źródło:
Computer Methods in Materials Science; 2020, 20, 4; 165-172
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Heat Transfer at the Solid to Solid Interface
Autorzy:
Rywotycki, M.
Malinowski, Z.
Falkus, J.
Sołek, K.
Szajding, A.
Miłkowska-Piszczek, K.
Powiązania:
https://bibliotekanauki.pl/articles/958225.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat transfer
inverse method
solid - solid interface
Opis:
In technological process of steel industry heat transfer is a very important factor. Heat transfer plays an essential role especially in rolling and forging processes. Heat flux between a tool and work piece is a function of temperature, pressure and time. A methodology for the determination of the heat transfer at solid to solid interface has been developed. It involves physical experiment and numerical methods. The first one requires measurements of the temperature variations at specified points in the two samples brought into contact. Samples made of C45 and NC6 steels have been employed in physical experiment. One of the samples was heated to an initial temperature of: 800°C, 1000°C and 1100°C. The second sample has been kept at room temperature. The numerical part makes use of the inverse method for calculating the heat flux and at the interface. The method involves the temperature field simulation in the axially symmetrical samples. The objective function is bulled up as a dimensionless error norm between measured and computed temperatures. The variable metric method is employed in the objective function minimization. The heat transfer coefficient variation in time at the boundary surface is approximated by cubic spline functions. The influence of pressure and temperature on the heat flux has been analysed. The problem has been solved by applying the inverse procedure and finite element method for the temperature field simulations. The self-developed software has been used. The simulation results, along with their analysis, have been presented.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 1; 341-346
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat Flux Identification at the Charge Surface During Heating in Chamber Furnace
Autorzy:
Gołdasz, A.
Malinowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/351346.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat flux
inverse method
finite element method
chamber furnace
Opis:
In this study, a method of determining the heat flux, which reaches the surface of a charge, has been presented with the use of an inverse analysis. The research on the heating process of a square 15HM steel charge was conducted in a natural gas-fired laboratory furnace. The inverse solution was based on the search of the minimum standard error between the measured and the calculated temperatures. The temperature of the charge has been calculated by the finite element method, solving the heat conduction equation for a square charge heated on all the surfaces. As a result, the mean value of the heat flux on each of the heated surfaces of the charge was estimated.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 2021-2026
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of coolant velocity on the local heat transfer coefficient during steel quenching
Autorzy:
Szajding, Artur
Gołdasz, Andrzej
Telejko, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/29520233.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
inverse method
heat transfer coefficient
boundary condition
quenching
Opis:
The results of the calculations of the local heat transfer coefficient HTC and a heat flux HF on the face of a cylindrical sample made of 1.0503 steel are presented. The sample was cooled from a temperature of approx. 930°C in a mineral oil having a temperature equal to 50°C. The experiments were performed for three speeds of the oil stream (0.2, 0.4 and 0.6 m/s). The oil stream was directed perpendicularly to the cooled surface. The temperature of each sample was measured with 4 thermocouples and recorded with a frequency of 10 Hz. The maximum values of HTC always occurred in the axis of the sample and were in the range of 8000 to 10,000 W/(m2 K). The results are presented in the form of useful graphs showing the dependence of HTC and HF on the surface temperature for various velocities of cooling oil. The calculations were made with self-developed software using the inverse solution of the boundary heat conduction problem.
Źródło:
Computer Methods in Materials Science; 2020, 20, 4; 157-164
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of heat flux at a solid-solid intreface
Autorzy:
Rywotycki, M.
Malinowski, Z.
Sołek, K.
Falkus, J.
Miłkowska-Piszczek, K.
Powiązania:
https://bibliotekanauki.pl/articles/356275.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting of steel
heat transfer
inverse method
rolls
Opis:
Determining the boundary conditions of heat transfer in steel manufacturing is a very important issue. The heat transfer effect during contact of two solid bodies occurs in the continuous casting steel process. The temperature fields of solids taking part in heat transfer are described by the Fourier equation. The boundary conditions of heat transfer must be determined to get an accurate solution to the heat conduction equation. The heat flux between the tool and the object processed depends mainly on temperature, pressure and time. It is very difficult and complicated to accomplish direct identification and determination of the boundary conditions in this process. The solution to this problem may be the construction of a process model, performing measurements at a test stand, and using numerical methods. The proposed model must be verified on the basis of parameters which can easily be measured in industrial processes. One of them is temperature, which may be used in inverse methods to determine the heat transfer coefficient. This work presents the methodology for determining the heat flux between two solid bodies staying in contact. It consists of two stages – the experiment and the numerical computation. The problem was solved by using the finite element method (FEM) and a numerical program developed at AGH University of Science and Technology in Krakow. The findings of the conducted research are relationships describing the value of the heat flux versus the contact time and surface temperature.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 79-86
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variational principles and natural boundary conditions for multilayered orthotropic graphene sheets undergoing vibrations and based on nonlocal elastic theory
Zasady wariacyjne i naturalne warunki brzegowe dla wielowarstwowych ortotropowych paneli grafenowych poddanych drganiom, sformułowane w ramach nielokalnej teorii sprężystości
Autorzy:
Adali, S.
Powiązania:
https://bibliotekanauki.pl/articles/279248.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
variational formulation
multilayered graphene sheets
non-local theory
vibrations
semi-inverse method
Opis:
Variational principles are derived for multilayered orthotropic graphene sheets undergoing transverse vibrations based on the nonlocal elastic theory of orthotropic plates which provide a continuum model for graphene sheets. The variational formulation allows the derivation of natural boundary conditions which are expressed in the form of a set of coupled equations for multilayered sheets as opposed to uncoupled boundary conditions applicable to simply supported and clamped boundaries and also in the case of a formulation based on the local (classical) elasticity theory. For the free vibrations case, the Rayleigh quotient is derived. The methods for the variational formulation use techniques of calculus of variations and the semi-inverse method for deriving variational integrals. Variational formulations provide the basis for a number of approximate and numerical methods of solutions and improve the understanding of the physical phenomena.
W pracy zajęto się problemem drgań poprzecznych ortotropowych paneli grafenowych, dla których sformułowano zasady wariacyjne na podstawie nielokalnej teorii sprężystości, co pozwoliło na budowę ciągłego modelu takich struktur. Formuła wariacyjna umożliwiła konstrukcję naturalnych warunków brzegowych wyrażonych zbiorem sprzężonych równań opisujących grafenowe panele wielowarstwowe w odróżnieniu od rozprzężonych warunków brzegowych stosowanych jedynie do zamocowań typu swobodne podparcie lub zamurowanie, jednocześnie przy zastosowaniu lokalnej (klasycznej) teorii sprężystości. Dla przypadku drgań swobodnych wyznaczono iloraz Rayleigha układu z grafenu. W prezentowanym sformułowaniu użyto odpowiednich technik obliczania funkcjonałów i półodwrotnej metody wyznaczania całek. Wykazano, że postać wariacyjna stanowi podstawę dla numerycznych metod poszukiwania przybliżonych rozwiązań i pogłębia zrozumienie zachodzących zjawisk fizycznych w takich układach.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 3; 621-639
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverse methods in hydrologic optics
Autorzy:
Gordon, H.R.
Powiązania:
https://bibliotekanauki.pl/articles/48466.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
water body
inverse method
fluorescence
inelastic process
optical property
inherent optical property
irradiance
Opis:
Methods for solving the hydrologic-optics inverse problem, i.e., estimating the inherent optical properties of a water body based solely on measurements of the apparent optical properties, are reviewed in detail. A new method is developed for the inverse problem in water bodies in which fluorescence is important. It is shown that in principle, given profiles of the spectra of up- and downwelling irradiance, estimation of the coefficient of inelastic scattering from any wave band to any other wave band can be effected.
Źródło:
Oceanologia; 2002, 44, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of distribution of moving heat source during milling of AISIH13 by inverse heat conduction method
Autorzy:
Farahani, Somayeh D.
Powiązania:
https://bibliotekanauki.pl/articles/279414.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
milling
inverse method
moving plane heat source
moving point heat source
cutting temperature
Opis:
This study presents an inverse heat transfer method to estimate the time history of a local heat flow into the work-piece during milling of AISIH13 with considering a 3D thermal model. Temperatures are measured using thermocouples within the work-piece providing input data for the inverse solver. The conjugate gradient method is used as an inverse solver to predict the local time dependent heat flow distribution on the cutting surfaces as well as the temperature distribution in the work-piece. A moving point heat source and a moving plane heat source with different heat source velocity is considered to investigate their influence on the estimated heat flow. Results indicate a good agreement between the experimental and estimated data with an average root mean square error less than 0.2 ◦C. It can be observed that the heat flow distribution is a function of heat source geometry, cutting speed and feed rate, but the temperature distribution is a weak function of geometry of the moving heat source. Changes of temperature with depth are studied. This study suggests that the developed inverse model can be successfully applied for estimating the heat flow and thermal field in the work-piece during milling.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 1081-1093
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Engineering design of low-head Kaplan hydraulic turbine blades using the inverse problem method
Autorzy:
Krzemianowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/200629.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inverse method
hydraulic turbine blade design
low-head Kaplan turbine
curvilinear coordinate system
Christoffel symbols
Opis:
The paper concerns the engineering design of guide vane and runner blades of hydraulic turbines using the inverse problem on the basis of the definition of a velocity hodograph, which is based on Wu’s theory [1, 2]. The design concerns the low-head double-regulated axial Kaplan turbine model characterized by a very high specific speed. The three-dimensional surfaces of turbine blades are based on meridional geometry that is determined in advance and, additionally, the distribution of streamlines must also be defined. The principles of the method applied for the hydraulic turbine and related to its conservation equations are also presented. The conservation equations are written in a curvilinear coordinate system, which adjusts to streamlines by means of the Christoffel symbols. This leads to significant simplification of the computations and generates fast results of three-dimensional blade surfaces. Then, the solution can be found using the method of characteristics. To assess usefulness of the design and robustness of the method, numerical and experimental investigations in a wide range of operations were carried out. Afterwards, the so-called shell characteristics were determined by means of experiments, which allowed to evaluate the method for application to the low-head (1.5 m) Kaplan hydraulic turbine model with the kinematic specific speed (»260). The numerical and experimental results show the successful usage of the method and it can be concluded that it will be useful in designing other types of Kaplan and Francis turbine blades with different specific speeds.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 6; 1133-1147
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of heat flux and temperature calculation on the control rod outer surface
Autorzy:
Taler, J.
Cebula, A.
Powiązania:
https://bibliotekanauki.pl/articles/240728.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
strumień ciepła
temperatura
wymiana ciepła
metoda inwersji
CFD
heat flux
heat transfer
inverse method
temperature
Opis:
The paper presents heat transfer calculation results concerning a control rod of Forsmark Nuclear Power Plant (NPP). The part of the control rod, which is the object of interest, is surrounded by a mixing region of hot and cold flows and, as a consequence, is subjected to thermal fluctuations. The paper describes a numerical test which validates the method based on the solution of the inverse heat conduction problem (IHCP). The comparison of the results achieved by two methods, computational fluid dynamics (CFD) simulations and IHCP, including a description of the IHCP method used in the calculation process, shows a very good agreement between the methods.
Źródło:
Archives of Thermodynamics; 2011, 32, 3; 157-173
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method
Autorzy:
Grądziel, S.
Powiązania:
https://bibliotekanauki.pl/articles/240169.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metoda inwersji
propagacja nacisków
szybkozmienna temperatura
współczynnik przenikania ciepła
heat transfer coefficient
inverse method
stress distribution
transient temperature
Opis:
The following paper presents the method for solving one-dimensional inverse boundary heat conduction problems. The method is used to estimate the unknown thermal boundary condition on inner surface of a thick-walled Y-branch. Solution is based on measured temperature transients at two points inside the element's wall thickness. Y-branch is installed in a fresh steam pipeline in a power plant in Poland. Determination of an unknown boundary condition allows for the calculation of transient temperature distribution in the whole element. Next, stresses caused by non-uniform transient temperature distribution and by steam pressure inside a Y-branch are calculated using the finite element method. The proposed algorithm can be used for thermal-strength state monitoring in similar elements, when it is not possible to determine a 3-D thermal boundary condition. The calculated temperature and stress transients can be used for the calculation of element durability. More accurate temperature and stress monitoring will contribute to a substantial decrease of maximal stresses that occur during transient start-up and shut-down processes.
Źródło:
Archives of Thermodynamics; 2011, 32, 3; 191-200
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of sound power level of machine by inverse method
Autorzy:
Piechowicz, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/2146645.pdf
Data publikacji:
2021
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
inverse method
sound power
sound pressure level
sound measurement
metoda odwrotna
moc akustyczna
poziom ciśnienia akustycznego
pomiar dźwięku
Opis:
The paper presents the inverse method to estimate the sound power level of machines operated in industrial environments. Values of the partial sound power sources of machine components could be predicted based on the distribution of sound field parameters measured around the machine. Assigning partial sound power levels of machine components allows for the effective selection of efficient noise protection solutions for this machine. Measurements were carried out in an actual mechanical workshop. The multichannel measurement system for simultaneous recording of sound pressure levels and the angle of phase angle shift was used in measurements. Based on the determined the sound power of partial sources, the A-weighted sound pressure levels at the operator's workplace were determined.
Źródło:
Vibrations in Physical Systems; 2021, 32, 1; art. no. 2021113
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody odwrotnej w celu zwiększenia możliwości pomiarowych metody anemometrii obrazowej (PIV)
Application of an inverse method for improvement of the measurement capability of the particle image velocimetry method
Autorzy:
Stryczniewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/212974.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
metody odwrotne
aerodynamika doświadczalna
numeryczna mechanika płynów
CFD
anemometria obrazowa
PIV
inverse method
applied aerodynamics
computational fluid dynamics (CFD)
Particle Image Velocimetry
Opis:
W pracy przedstawiono koncepcję zwiększenia możliwości pomiarowych metody anemometrii obrazowej (Particie Image Velocimetry - PIV) poprzez zastosowanie zastosowaniu wyniku symulacji numerycznej w procesie analizy danych pomiarowych. Badania przeprowadzono w celu weryfikacji następującej hipotezy: uzyskanie zgodności wyniku pomiaru metodą PR" oraz wyniku numerycznej symulacji przepływu umożliwi wyznaczenie parametrów przepływu, będących poza zakresem pomiarowym metody PIV'. W ramach pracy przeprowadzono testy numeryczne, w których dokonano estymacji parametrów przepływu wokół profilu NAC A0009. Identyfikacj ipodległa prędkość przepływu strumienia niezaburzonego. W celu sprawdzenia poprawności zaproponowanej procedury estymacji parametrycznej, algorytm przetestowano na symulowanych danych pomiarowych. Wyniki badań testowych dowodzą poprawności opracowanych procedur oraz stanowią przyczynek do rozpoczęcia pracy nad nową metodyką analizy wyników7 pomiarów metodą PIV.
In the presented paper an application of the inverse method for improvement of the measurement capability of the Particle Image Velocimetry method have been discussed. The paper introduces a new approach for PIV data analysis. In a course of the research following thesis has been verified: fitting of the experimental PIV data and a direct numerical problem solution, will lead to determination of flow parameters unobtainable for PIV method. In order to verify the proposed methodology numerical tests has been performed. The parameters of the flow over NACA0009 airfoil has been estimated. The parameter of has been estimated with developed optimization algorithm. The presented results proved the feasibility of proposed methodology and contributes to development of new PIV data post-processing procedure.
Źródło:
Prace Instytutu Lotnictwa; 2016, 2 (243); 93-107
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-Channel System for Sound Creation in Open Areas
Autorzy:
Gołaś, A.
Suder-Dębska, K.
Powiązania:
https://bibliotekanauki.pl/articles/176685.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound creation system
open area
spatial impression
noise
geometrical method
inverse image source method
Opis:
There are typically two systems in use for sound reinforcement in open areas: the central, “wall of sound” system with speakers localized at the sides of the stage, and the zone system, in which additional speakers are introduced to obtain a uniform sound pressure level throughout the area of listening. In the past two decades the line array systems gained great popularity. The main purpose of their use is to obtain a uniformly distributed sound level throughout the listening area in order to achieve good speech intelligibility. The present paper aims to present an alternative and original method of sound reinforcement in open areas which is in contrast to the above solutions. This new method allows achieving a uniformly distributed sound pressure and good speech intelligibility in the area of interest, and also allows to gain spatial sound impression that accompanies sound reproduction in concert halls. Another advantage of the proposed system is the reduction of the sound level outside the area of interest, i.e. reduction of the noise level outside the area of listening.
Źródło:
Archives of Acoustics; 2012, 37, 3; 323-329
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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