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1

Rekonstrukcja wyglądu pałacu w Starych Tarnowicach z wykorzystaniem technik modelarstwa eksperymentalnego

Pocisk-Dobrowolski Jerzy

Builder

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2023

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R.27, nr 5

36--39

PL

Ostatnie lata charakteryzują się gigantycznym przyspieszeniem w rozwoju wszelkiego typu technologii związanych z tworzeniem i przekazem graficznych rozwiązań, w tym również dotyczących rekonstrukcji i odbudowy obiektów zabytkowych. Ważne jest jednak zauważenie, że wraz z rozwojem technologii mentalnie nadal jesteśmy przyzwyczajeni do odbioru informacji wizualnych przekazywanych m.in. za pomocą obiektów trójwymiarowych, które są dla nas ciągle bardziej czytelne od najlepiej przedstawionych wizualizacji czy też projektów czysto technicznych. Stąd też nie należy rezygnować dla samej zasady z tradycyjnych form działań wspierających podejmowanie właściwych decyzji przy rekonstrukcji zabytków. Modelarstwo eksperymentalne jest dowodem na to, że jego wykorzystanie nadal jest w stanie skutecznie ułatwiać podejmowanie decyzji w procesie ratowania obiektów zabytkowych. Dowodem na to jest skuteczne zastosowanie makiety rekonstrukcyjnej jako elementu wspierającego wybór właściwych rozwiązań w trakcie odbudowy renesansowego pałacu w Starych Tarnowicach.

EN

Recent years have been characterised by a gigantic acceleration in the development of all kinds of technologies related to the creation and communication of graphic solutions, including those for the reconstruction and restoration of historic buildings. However, it should be noted that with the development of technology, mentally we are still accustomed to receiving visual information conveyed, among other things, by means of three-dimensional objects, which are still more legible to us than the best presented visualisations or purely technical designs. Hence, for the sake of principle alone, traditional forms of activities that support good decision-making in the restoration of monuments should not be abandoned. Experimental modelling is proof that its application can still effectively facilitate decision-making in the process of saving historic buildings. Proof of this is the successful use of a reconstruction mock-up as an element supporting the selection of appropriate solutions during the reconstruction of the Renaissance palace in Stare Tarnowice.

2

Experimental Modeling to Facilitate Removal of Inclusion Contaminants from the Contact Surface in Transversal Extrusion Processes

Skorulski G., Piwnik J., Hościło B.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 1 spec.

209--212

EN

The paper presents experimental optimization of geometrical conditions regarding the shape of billet’s end pieces in the extrusion process of aluminum alloys. The experiments were performed using appropriately pre-treated plasticine as a substitute material. A special test stand was built using a Plexiglass die in order to make it possible to conduct observations and measurements of the modeled contamination surface. To find the best solution, a great number of shape variants of the billets and of their heating temperatures were experimentally analyzed. An attempt was made to find such a solution that could not only resolve the issue of the removal of contaminants from the contact surface of the pre- heated billets but also develop the least complicated technology of billet fabrication. The test results show how to develop the design process and production technology and also offer advice how to improve the quality of the produced profiles. Finally the authors recommend such a shape for the billets that will ensure effective removal of contaminants from the contact surfaces.

3

Modeling of a two stages electrostatic air precipitation process using response surface modeling

Berrached D., Tilmatine A., Miloua F., Bengrit M.

Archives of Electrical Engineering

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2014

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Vol. 63, nr 4

609--619

EN

Any industrial process needs to work with the optimal operating conditions and thus the evaluation of their robustness is a critical issue. A modeling of a laboratoryscale wire-to-plane two stages electrostatic precipitator for guiding the identification of the set point, is presented this in paper. The procedure consists of formulating recommendations regarding the choice of optimal values for electrostatic precipitation. A twostages laboratory precipitator was used to carry out the experiments, with samples of wood particles of average granulometric size 10 μm. The parameters considered in the present study are the negative applied high voltage of the ionization stage, the positive voltage of the collection stage and the air speed. First, three “one-factor-at-a-time” experiments were performed followed by a factorial composite design experiments, based on a two-step strategy: 1) identify the domain of variation of the variables; 2) set point identification and optimization of the process.

4

The Influence of Segregation Phenomena on Quality of Product in Extrusion Process

Skorulski G., Piwnik J., Baranowski P.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 3 spec.

251--254

EN

The segregation phenomena and formation of agglomerate have the basic influence on structure of the final product. The aim of this work is analyzing the phenomena of segregation in semi-solid extrusion process, using several kind of substitute materials, which can simulate the thixotrophic fluid behavior and displacement of solid particles. The experimental researches are made to investigation of segregation in the near-wall layers and the formation of agglomerate. Especially, the distribution of the solid particles at the end of extrusion process have been taken into consideration. Theoretical criteria describe the critical value of the energy liberated at the surfaces by the action of forces depends on the temperature, the pressure, the yield stress and the physical state and degree of intimacy of the contacting surfaces. The theory has been tested experimentally using a silicon polymer as a substitute material. Experimental stand with a Plexiglass die was prepared, such that the velocity fields at the surfaces could be observed and measured during plastic flow, allowing the empirical coefficients in the mathematical formulation to be estimated. On the basis of the theory and experiment an optimal die chamber was designed for a die with a complex shape.

5

The Favourable Choice of the Shape of Billet's Contact Surface to Quality of Extruded Aluminium Profiles

Skorulski G., Piwnik J., Baranowski P.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 3 spec.

245--250

EN

The theoretical and experimental method of optimization the aluminium billet’s contact surface during extrusion have been presented in this paper. The theoretical assumption, based on welding criteria, have been confirmed by experimental researches. The technique of measurement has been shown as well. Experiments are made using plasticine as a substiute material. Some kind of different variants have been investigated. The theory and experiments have been provided to optimize the modeling shape and may help in design and technology. The theory has been tested experimentally using a plasticine as a substitute material and a plexiglass die such that the velocity fields at the surfaces could be observed and measured during plastic flow, allowing the empirical coefficients in the mathematical formulation to be estimated. On the basis of the theory and experiments an optimal billet’s contact surface was proposed.

6

Modelling of semi-liquid aluminium flow in extrusion with temperature effect

Skorulski G., Piwnik J.

Archives of Foundry Engineering

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2007

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Vol. 7, iss. 2

25-30

EN

During thixoforming, when the material is in the semi-liquid state, it exhibits thixotropic properties, i.e. the unsupported material remains stiff and holds its shape so it can be readily handled, but rapidly thins and flows like a liquid when sheared. It is this behaviour that is the key to the thixoforming process where material flows as a semi-liquid slurry into a die, as in conventional die-casting. Modelling the influence of the temperature distribution heterogeneity on deformation mechanisms during extrusion of the aluminium alloys in semi-liquid phase, the way of preparing samples and experimental technique has been analysed in the following work. There were made an analysis on the influence of the possible temperature distribution in recipient obtained during heating it on the extrusion process proceedings. The conclusions concerning stability of the process and appearing during it deformation mechanisms had been drawn on the ground of the received results. The plasticine and rape oil have been choosen as a substitute materials. Some kind of different variants have been investigated used a special experimental stand. The results of the tests presented below prove that the proposed technique can provide valuable insight into the material flow during deformation of aluminium alloys in the semi-liquid state and thus can give some guidance concerning the desirable temperature distribution within the workpiece.

7

Modelling of semi-liquid aluminium flow in extrusion

Skorulski G., Piwnik J.

Archives of Foundry Engineering

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2007

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Vol. 7, iss. 2

31-36

EN

Experimental modeling using substitute materials is usually a simply way to obtain satisfacted results. This kind of experiment is characterizing by low cost. The significant results may be quickly applying using theory of probability. The way of modelling the deformation mechanisms during extrusion of aluminium alloys in semi - liquid phase, the way of preparing samples and experimental technique has been analysed in the following work. On the ground of received results (i.e. registrations of consecutive process steps) the grid of the flow velocity vectors on a flat sample surface was done. It allowed to draw conclusions which one of the basic deformation mechanisms is dominant in particular stage of the process. The technique of measurement has been shown as well. Experiments are made using plasticine and rape oil as a substiute materials. Some kind of different variants have been investigated. To ensure that such model experiments provide useful information it is essential to select model materials and prepare samples that would exhibit (preferably at room temperature) similar behaviour and similar deformation mechanisms as those present during the actual deformation process of aluminium alloys in a semi-liquid state. In particular the FLS, SS and PDS mechanisms should be adequately reproduced.

8

Experimental modelling of the influence of boundary conditions on kinematics of the extrusion process

Skorulski G.

Engineering Transactions

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2005

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Vol. 53, iss. 1

31-41

EN

The aim of this paper is to analyses the influence of boundary conditions on plastic flow kinematics during hot extrusion of aluminium alloys. Clay and plasticine have been used as a substitute material. The shape and distribution of a dead zone, conditions of increasing the boundary layers and their influence on flow kinematics have been done using the modelling experiment. Kinematics of plastic flow and especially, range of deformation region allows to predict stresses distribution on contact surface between the die, container and the extruded material.

9

Physical and numerical modeling of heat-flow processes in tangentially pulverized fuel-fired boiler

Barański J., Stąsiek J., Blasiak W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 3

347-362

EN

The paper presents results of three-dimensional physical modeling and computer simulations of fluid-flow structures, mixing and combustion processes in a 125 MW tangentially fuel-fired boiler and additional fuel - natural gas. This method is commonly called the reburning process, with an emphasis on the reduction of CO, NOx and SOx. The co-firing process is realized between the main coal burners and additional fuel nozzles. To improve the mixing and combustion processes, a physical technique, the so-called acid/alkali technique, is used to optimize the placement and direction of additional air and fuel nozzles. The best result obtained from physical modeling experiments is studied using numerical simulations with the FLUENT commercial code. Numerical modeling results are then used to analyze the performance of an industrial boiler. These results, compared with measurements in a real boiler, seem to be in good agreement with each other.

10

Metematiceskoe i eksperimental'noe modelirovanie dvizenia polidispersnyh sred v kanalah sloznoj geometrii

Slobodkina F. A.

Prace Instytutu Górnictwa Naftowego i Gazownictwa

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2002

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nr 116 wyd. konferencyjne

97--101

11

Strain state and strength of acetabular component of total hip-joint endoprosthesis.

Jira J., Jirova J., Micka M.

Acta of Bioengineering and Biomechanics

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1999

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Vol. 1, nr 2

79-83

EN

The paper deals with the new cementless acetabular cup of the Beznoska type. This cup is made of 1 mm thick titanium covering and polyethylene inner layer. Good initil implant stability is ensured by titanium projections on the outer surface. The purpose of the experimental research was to measure strains at selected points on the outer surface of the artificial cup. A computation model enables us to analyse the strain state generated not only by concentrated load, but also by uniformly distributed load or by varing load. The aim of the research was to analyse the strain state of the acetabular component and to find out the limit loading for assesment of strength and the loss of stability of the cup structure.

12

Experimental modeling of large scale gas fuel injector for IC piston engines

Bocian P., Wojciechowski J., Rychter T.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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1998

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nr 8

81-84

EN

Supplying 1C piston engines with gaseous fuels is one of well known approaches to reduce the content of polluting components in exhaust gases. One of methods for gaseous fuel supply considered is a high-pressure direct gas injection, which is currently studied in a number of laboratories. The successful application of this method requires the proper organisation of the combustion system and particularly - the careful treatment of the gas injection process and its mixing with the surrounding air. Very important is also the location of the choice of the ignition point in order to assure repeatable combustion initiation. The mixing process strongly depends on the shape and the direction of the injected gas which, in turn, depends on the injector tip geometry. The main objective of the presented experimental analysis is to determine the best of the gaseous fuel single-nozzle injector, would be able to assure the proper mixing of the gas with air. The investigations were performed under "cold" conditions with the use of the model gas injector in geometrical scale 10:1. The conventional-like form of the nozzle was with annular gas flow area created by the gap between the pintle and the nozzle wall. The element as well as experimental conditions be easily changed in the wide range This made it possible to select jet geometry (the form, length and convergence angle of the pintle, nozzle outlet and divergence angle etc.). It also for the longitudinal vorticity control: from axial flow to the flow with strong velocity component, or any form. The injection gas pressure was 0.5 MPa, which allowed for the rough simulation engine conditions, for a large spectrum of flow geometries (pintle, nozzle, vorticity). The CO2 was as a working medium. There were used: flow visualisation by schlieren method, the hot-wire technique for determination of velocity especially designed hot-wire probe and the infrared energy apparatus to measure - respectively - the high and low or very low injected gas local concentration. Some interesting injector configurations were chosen for posterior measurements of velocity field in the free circular jet of gas past the injector. The study allowed for drawing the optimal schema of the single-nozzle gas fuel injector, which has become the base for the combustion tests in a normal-scale injection system.