Wyniki wyszukiwania - BazTech

1

Estimation of sound power level of machine by inverse method

Piechowicz Janusz

Vibrations in Physical Systems

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2021

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Vol. 32, nr 1

art. no. 2021113

EN

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.

2

The influence of coolant velocity on the local heat transfer coefficient during steel quenching

Szajding Artur, Gołdasz Andrzej, Telejko Tadeusz

Computer Methods in Materials Science

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2020

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Vol. 20, No. 4

157--164

EN

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.

3

The effect of the assumed thermophysical properties of steel on the heat transfer calculation result in contact phenomena

Rywotycki Marcin, Malinowski Zbigniew, Przyłucka Aleksandra, Sołek Krzysztof

Computer Methods in Materials Science

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2020

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Vol. 20, No. 4

165--172

EN

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.

4

Estimation of distribution of moving heat source during milling of AISIH13 by inverse heat conduction method

Farahani Somayeh D.

Journal of Theoretical and Applied Mechanics

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2019

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Vol. 57 nr 4

1081--1093

EN

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.

5

Inverse estimation of model parametersfor newborn brain cooling process simulations

Bandoła Dominika, Ostrowski Ziemowit, Rojczyk Marek, Walas Wojciech, Halaba Zenon, Nowak Andrzej J.

Computer Assisted Methods in Engineering and Science

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2019

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Vol. 26, no. 2

93--104

EN

In this work, a three-dimensional simplified computational model was built to simulate the passive thermo-physiological response of part of a newborn’s head for neonate’s selective brain cooling. Both metabolicheat generation and blood perfusion were considered. The set of model parameters was selected anda sensitivity study was carried out. Analysis of dimensionless sensitivity coefficients showed that the mostimportant are: the contact thermal resistance between the cool-cap and skin, the thermal resistance ofthe plastic wall material, and deep (arterial) blood temperature. The function specification method wasapplied to estimate the value of the contact resistance. Two, four and six computationally simulated mea-surements with different uncertainties were used to adjust random contact resistance value to the assumedone. Results showed that when using only two measurements having 2% of the uncertainty, the error ofestimation does not exceed 9.8%. However, when using six measurements having 1% of uncertainty, theresulting estimation is burdened with an error of 0.3% only.

6

Engineering design of low-head Kaplan hydraulic turbine blades using the inverse problem method

Krzemianowski Z.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 6

1133--1147

EN

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.

7

Determination of heat flux at a solid-solid intreface

Rywotycki M., Malinowski Z., Sołek K., Falkus J., Miłkowska-Piszczek K.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

79--86

EN

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.

8

Wyznaczenie wartości współczynnika wymiany ciepła w strefie pierwotnego chłodzenia procesu COS z wykorzystaniem metody Inverse

Miłkowska-Piszczek K., Drożdż P.

Hutnik, Wiadomości Hutnicze

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2017

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Vol. 84, nr 11

489--492

PL

Wyznaczenie empirycznych wartości warunków brzegowych oraz parametrów materiałowych jest kluczowe do uzyskania poprawnych wyników modelowania numerycznego. Obliczenie wartości współczynnika wymiany ciepła w strefie pierwotnego chłodzenia maszyny COS jest zadaniem złożonym, ze względu na model wymiany ciepła pomiędzy pasmem a krystalizatorem. W pracy zaprezentowano sposób wyznaczenia średniej wartości współczynnika wymiany ciepła pomiędzy krzepnącym pasmem a ścianą krystalizatora za pomocą metody Inverse. Jako parametry wejściowe wykorzystano wartości temperatury, pochodzące z termopar zainstalowanych w ścianach krystalizatora maszyny COS służącej do odlewania wlewków płaskich. Do obliczeń numerycznych wykorzystano komercyjny pakiet oprogramowania VisualCAST z solverem obliczeniowym ProCAST 2016.

EN

Determination of the empirical values of the boundary conditions and material parameters is a crucial in order to obtain correct numerical modeling results. Calculation of the heat transfer coefficient value in the primary cooling zone continuous casting machine is a complex task, concerning heat transfer model between the mould and the strand surface. This paper presents method of calculation the average value of the heat transfer coefficient between the outer layer of the solidified strand shell and the mould wall surface. The values of the temperature measured by thermocouples – installed in the walls of slab casting machine mould - were used as an input parameters. The VisualCAST software package with a ProCAST2016 solver was used for the numerical calculations.

9

Identification of the Heat Transfer Coefficient at the Charge Surface Heated on the Chamber Furnace

Gołdasz A., Malinowski Z.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

509--513

EN

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.

10

Application of 3D DIC Displacement Field Measurement in Residual Stress Calculations

Brynk T.

Advances in Materials Science

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2017

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Vol. 17, nr 3(53)

46--53

EN

The knowledge of residual stress distribution is of great importance from the viewpoint of both, industrial and basal research. The most commonly utilized method of residual stress determination is based on strain measurements near the drilled holes of known geometry made by means of tensometric rosettes. An alternative to tensometers way of strain measurement is Digital Image Correlation (DIC). This optical method utilizes digital images registered during observed object deformation and delivers results in the form of displacement field maps consisting of hundreds or thousands of data points. Therefore, it is possible to deliver much more data in comparison to rosettes (only 3 or 6 tensometers, usually) and use them in the inverse method numeric procedure for residual stress calculations. In the paper the experimental stand consisting of micro driller and stereo imaging system for 3D DIC measurement and its application to residual stress estimation in prestrained steel samples are presented followed by obtained results discussion.

11

Zastosowanie metody odwrotnej w celu zwiększenia możliwości pomiarowych metody anemometrii obrazowej (PIV)

Stryczniewicz W.

Prace Instytutu Lotnictwa

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2016

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Nr 2 (243)

93--107

PL

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.

EN

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.

12

Wymiana ciepła przy przeróbce plastycznej metali – porównanie modeli

Rywotycki M., Malinowski Z., Szajding A., Falkus J., Sołek K., Miłkowska-Piszczek K.

Hutnik, Wiadomości Hutnicze

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2016

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Vol. 83, nr 1

13--17

PL

W artykule zostały porównane wyniki obliczeń pola temperatury wsadu uzyskane z wykorzystaniem modeli zaczerpniętych z literatury oraz własnym modelem wymiany ciepła. Wartość współczynnika wymiany ciepła została uzyskana z badań własnych z zastosowaniem nowej metodyki określania strumienia ciepła przepływającego między powierzchniami wymieniającymi ciepło. Składa się ona z dwóch etapów: eksperymentu i obliczeń numerycznych. Badania eksperymentalne zawierają pomiary zmian temperatury w określonych punktach w dwóch próbkach pozostających w kontakcie. Część numeryczna wykorzystuje rozwiązanie odwrotne i metodę elementów skończonych do obliczania strumienia ciepła na powierzchni styku.

EN

The results of calculations of the temperature field of the deformed material conducted using heat transfer coefficient form literature are compared with that obtained for developed heat transfer boundary condition model. The developed heat transfer boundary condition model has been obtained using a new methodology for determining heat flux transferred between two solid surfaces. The methodology consists of two parts: experimental and numerical one. The experimental part involves measurements of temperature at specific points in the two samples brought into contact. The numerical part uses an inverse method and the finite element method to calculate the heat flux at the interface.

13

Współczynnik wymiany ciepła na powierzchni płyty osłoniętej ekranem cieplnym

Gołdasz A., Malinowski Z.

Hutnik, Wiadomości Hutnicze

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2016

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Vol. 83, nr 4

186--191

PL

Współczynnik wymiany ciepła na powierzchni płyty osłoniętej ekranem cieplnym i bez osłony wyznaczano z zastosowaniem rozwiązania odwrotnego. Badania chłodzenia płyty przeprowadzono na zaprojektowanym i wykonanym stanowisku badawczym. Pomiar temperatury płyty ze stali EN 1.4724 realizowano za pomocą 9 termoelementów typu K umieszczonych 2 mm pod powierzchnią chłodzoną. Proces chłodzenia w powietrzu realizowano w 2 wariantach: w obecności ekranu aluminiowego oraz bez ekranu. Podczas chłodzenia mierzono temperaturę płyty od 800oC do około 40oC. Rozwiązanie równania przewodzenia ciepła w chłodzonej płycie oparto na metodzie elementów skończonych. Zastosowano nieliniowe funkcje kształtu opisane wielomianami Hermite’a. Przeprowadzono testy dokładności rozwiązania odwrotnego, które wykazały jego poprawność. Rozkład współczynnika wymiany ciepła w czasie aproksymowano za pomocą parabolicznych funkcji kształtu.

EN

An inverse method has been applied in to determine the heat transfer coefficient on the surface of a plate protected by a thermal shield and without protection. For purposes of the analysis a dedicated test stand has been designed. Temperature measurement of EN 1.4724 steel was executed with nine K type thermocouples placed 2 mm under the cooled surface. The cooling process in air was executed in two modes: with and without the aluminum shield. The temperature has been measured during plate cooling from 800oC to about 40oC. The solution of the heat conduction equation in the cooled plate was based on the finite element method. Nonlinear shape functions described by Hermite polynomials have been applied. The accuracy of the inverse solution has been tested and justified. The distribution of heat transfer coefficient in time was approximated with the use of quadratic shape functions.

14

Modelling of Heat Transfer at the Solid to Solid Interface

Rywotycki M., Malinowski Z., Falkus J., Sołek K., Szajding A., Miłkowska-Piszczek K.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 1

341--346

EN

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.

15

Heat Flux Identification at the Charge Surface During Heating in Chamber Furnace

Gołdasz A., Malinowski Z.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 4

2021--2026

EN

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.

16

Zastosowanie metody odwrotnej do wyznaczania dyfuzyjności cieplnej materiału warstwy pokrycia próbki w badaniach metodą powierzchniowego wymuszenia impulsowego

Stryczniewicz W., Panas A. J.

Modelowanie Inżynierskie

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2014

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T. 21, nr 52

193--200

PL

W pracy omówiono zastosowanie rozwiązania zagadnienia odwrotnego do wyznaczania składowej poprzecznej dyfuzyjności cieplnej materiału warstwy pokrycia próbki w badaniach metodą chwilowego powierzchniowego źródła ciepła. Dane doświadczalne uzyskano z zastosowaniem dyfuzometru LFA 457 Netzsch. Wymuszenie cieplne realizowano metodą nagrzewania laserowego. Przedstawiona metodyka opracowania danych doświadczalnych służy do określenia właściwości termofizycznych materiału cienkiej warstwy naniesionej na powierzchnię próbki – nośnika warstwy. Próbki testowe wykonano z materiału o znanych właściwościach. W celu identyfikacji parametrów warstwy opracowano algorytm optymalizacyjny wykorzystujący metodę Levenberga-Marquardta. Danymi przetwarzanymi przez program są zapisy cyfrowe odpowiedzi termicznej badanego obiektu w postaci względnej zmiany temperatury w czasie. Zagadnienie proste jest rozwiązywane metodą elementów skończonych. Numeryczny model próbki pokrytej badaną warstwą materiału wykonany został w programie Comsol Multiphysics. Przedstawione w pracy wyniki testowych badań doświadczalno-numerycznych dowodzą poprawności i efektywności opracowanych procedur badawczych.

EN

Application of the inverse method for investigation of a thin layer coating thermal diffusivity have been discussed. The problem concerns determination of the out off plane thermal transport prosperities of the thin layer material deposited onto a standard specimen of a priori known thermophysical properties. In order to estimate the un-known thermal diffusivity a multi-parametrical identification has been performed. The identification procedure applies a sample temperature response signal as an input. The direct problem is solved applying Finite Element Method. The appropriate numerical model have been developed utilizing Comsol/Multiphysics software. model was incorporated into a specially developed Matlab program. The parametrical estimation procedure uses the Levenberg-Marquardt algorithm. The experimental data used has been supplied utilizing Netzsch LFA 457 laser flash apparatus. The analyses performed proved efficiency and shoved performance of the elaborated procedure.

17

Tomografia sejsmiczna w górnictwie

Dębski W.

Przegląd Górniczy

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2012

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T. 68, nr 7

67--71

PL

Prędkościowa tomografia sejsmiczna jest techniką bezinwazyjnego obrazowania budowy wewnętrznej próbek skalnych, masywu skalnego, struktur geologicznych itp. w skalach począwszy od ułamka metra do tysięcy kilometrów. Otrzymywane tą techniką przestrzenne rozkłady prędkości fal P i S są zwykle interpretowane w kontekście strukturalnej budowy badanego górotworu. Jednakże, z punktu widzenia zastosowań w górnictwie jednym z najważniejszych elementów badania tomograficznego jest próba interpretacji otrzymanego obrazu tomograficznego pod kątem stanu naprężeń w górotworze. Osiągnąć to można albo przez próbę korelacji aktywności sejsmicznej z anomaliami rozkładu prędkości albo przez interpretacje anomalii prędkości pod kątem zmiennego w przestrzeni pola naprężeń. Niezależnie od wybranego podejścia dla poprawnej interpretacji tomogramów bardzo ważna jest ocena wiarygodności otrzymanych pól prędkości. Celem niniejszej pracy jest przybliżenie zasad tomografii sejsmicznej oraz wspomnianego powyżej dwoistego podejścia do praktycznej interpretacji wyników badań tomograficznych.

EN

The seismic velocity tomography is a non-destructive technique of imaging of the structure of rock samples, rock mass, geological structures etc. at scales ranging from centimetres up to thousands of metres. The obtained by use of this technique spatial distributions of P and S waves are usually interpreted in the context of the internal structure of the imaged rock mass. However, from the point of view of applications in mining one of the most important elements of tomographic inversion is the attempt of interpretation of the obtained tomographic image in the context of the state of stresses in the rock mass. This can be achieved either by an attempt of correlation of seismic activity with anomalies of the velocity distribution or by the interpretation of velocity anomalies in terms of lithological parameters. Independently of the chosen approach, for correct interpretation of tomograms very important is the assessment of reliability of obtained velocity fields. The aim of the present work is the approximation of seismic tomography rules and mentioned above dual approach to the practical interpretation of tomographic investigation results.

18

Multispectral polarized BRDF: design of a highly resolved reflectometer and development of a data inversion method

Riviere N., Ceolato R., Hespel L.

Optica Applicata

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2012

|

Vol. 42, nr 1

7-22

EN

Multispectral and polarized light reflectance measurements are very useful to characterize materials such as paint coatings. This article presents an overview of an automated high-angular resolved, in-plane multispectral polarized reflectometer and its calibration process. A comprehensive study based on multispectral BRDF and DOLP measurements is conducted on different colour and glossy aspects of paint coatings. An original inverse method from in-plane measurements is used to model the out-of-plane BRDF and to investigate the role of the surface and subsurface scattering phenomena in its components.

19

Identification of thermal operation conditions of water-wall tubes using eccentric tubular tube meters

Taler J., Taler D., Sury A.

Rynek Energii

|

2011

|

nr 1

164-171

EN

The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. First, formulas for the review factor defining the heat flux distribution on the outer surface of the flux tube were derived. The exact analytical expressions for the view factor compare very good with approximate methods for determining view factor which are used by the ANSYS software. The parameters appearing in the boundary conditions on the outer and inner surfaces of the water flux-tube: the heat flux, the heat transfer coefficient and temperature of the water-steam mixture are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

PL

Opracowano konstrukcję termometrycznej wstawki pomiarowej do identyfikacji warunków brzegowych w rurach ekranowych. Wstawka wykonana jest z krótkiego odcinka rury mimośrodowej. Nieznane parametry: obciążenie cieplne ekranu, współczynnik wnikania ciepła na powierzchni wewnętrznej oraz temperatura mieszaniny parowo-wodnej wyznaczane są na podstawie pomiaru temperatury metalu wewnątrz lub na powierzchni wstawki. Cztery termoelementy zainstalowane są wewnątrz wstawki od strony ogniowej, w pobliżu jej powierzchni wewnętrznej i zewnętrznej. Piąty termoelement usytuowany jest na zewnętrznej powierzchni wstawki od strony izolacji kotła. Poszukiwane parametry dobierane są tak, aby suma kwadratów różnic temperatur zmierzonych i obliczonych była minimalna. Nieliniowe zagadnienie najmniejszych kwadratów rozwiązane zostało za pomocą metody Levenberga-Marquardta. Warunki wymiany ciepła w sąsiednich rurach ekranowych nie mają wpływu na pole temperatury we wstawce pomiarowej, co ma korzystny wpływ na dokładność wyznaczanych parametrów.

20

Verification of heat flux and temperature calculation on the control rod outer surface

Taler J., Cebula A.

Archives of Thermodynamics

|

2011

|

Vol. 32, no. 3

157-173

EN

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.