Wyniki wyszukiwania - BazTech

1

Introduction to non-linear Thermal-FSI on the example of transient load of a thin-walled container

Kraszewski B.

Zeszyty Energetyczne

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2018

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T. 5

1--13

EN

This paper presents the problems associated with the transient thermal load of structures exhibiting a non-linear relationship between load and strain. The mathematical model required to comprehensively describe the relationship between fluid and solid has been shown from different perspectives. In addition, the Newton-Raphson method has been referred to as a way of solving nonlinear equations. The article also presents the assumptions and results of numerical analysis of thin-walled container thermally loaded by contact with hot water. The conclusions drawn emphasize the importance of Thermal-FSI tools, especially in the power engineering sector.

2

On an approach to the thermo-elasto-plastic failure based on the Burzynski criterion

Banaś K., Badur J.

Transactions of the Institute of Fluid-Flow Machinery

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2017

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nr 136

65--76

EN

In this paper the comparison of material eort models: the classic Huber-Mises-Hencky approach and the Burzynski condition was presented. Burzynski yield condition is pressure sensitive and naturally takes into account the strength dierential eect, which has been observed in nickel-base super alloys such as Inconel 718. Investigation was performed during thermal-uidstructure interaction analysis of a power turbine guide vane of turbine helicopter engine PZL- 10W. Firstly, computational uid dynamics conjugate heat transfer analysis was carried out, then stress analysis was performed with boundary conditions obtained via computational uid dynamics analysis. During stress analysis, two mentioned above equivalent stress denitions were applied and dierence in material eort modelling by them was shown.

3

Thermal-FSI modeling of flow and heat transfer in a heat exchanger based on minichanels

Kornet S., Ziółkowski P., Jóźwik P., Ziółkowski P. J., Stajnke M., Badur J.

Journal of Power Technologies

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2017

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Vol. 97, nr 5

373--381

EN

In this paper selected numerical modelling problems for an advanced thermal-FSI ("Fluid Solid Interaction") mini-channel heat exchanger model are presented. Special attention is given to the heat transfer between the separated mediums for different mass flows. Similar modelling problems have also been discussed in the literature dedicated to numerical and theoretical modelling problems for typical heat exchangers [1, 2, 3]. Basic tests, including a comparison with experimental data, have been conducted using a Mini-channel Plate Heat Exchanger (MPHE). The MPHE was made out of two gasketed brazed plates with 40 mm long rectangular cross section channels (width - 1 mm, depth - 700 μm). The thermal-FSI analysis was applied for the heat exchanger model with one hot and one cold water flow passage through the mini-channels. Satisfactory agreement between the modelling results and the experimental data [4] was obtained.

4

Znaczenie głębokości obszaru strefy wpływu ciepła na rodzaj przeprowadzanej rewitalizacji przy uszkodzeniach wirników

Badur J., Bzymek G., Majkowska A., Sławiński D., Ziółkowski P., Ziółkowski P. J.

Instal

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2015

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nr 12

36--40

PL

Strefa wpływu ciepła (HAZ) ma szczególne znaczenie zarówno w procesach spawalniczych, jak i podczas różnego typu zdarzeń wynikających z zatarcia się uszczelnień, panwi łożysk, czopów itp. prowadzących do stopienia i zmiany struktury materiału. Zjawisku temu towarzyszy znaczny przyrost temperatury, który może być spowodowany wewnętrznym źródłem ciepła: bądź to termicznym, jak i również mechanicznym wywołanym wzajemnym tarciem stykających się powierzchni. W celu wyznaczenia głębokości obszaru strefy wpływu ciepła i tym samym znalezienia miejsc ewentualnych zmian fazowych w strukturze metalu, a także miejsc uplastycznienia konstrukcji, wykonano szereg symulacji numerycznych thermal-FSI. Jako warunki brzegowe zadano źródła ciepła na czopie łożyska zmienne w czasie trwania zjawiska. W symulacjach thermal-FSI, wykorzystano autorski model źródła ciepła zaimplementowany do kodu komercyjnego, którego zadaniem było oszacowanie rozkładu temperatur, jaki wygenerowany został w trakcie analizowanego zdarzenia. W dalszej kolejności, dla wyznaczenia głębokości pól płynięcia plastycznego metalu panwi i korpusu łożyska oraz czopa wirnika zaadaptowano model plastyczności Burzyńskiego. Stałe do modelu opisującego wielkość generowanego ciepła zweryfikowano eksperymentalnie. Wyniki uzyskane w zaproponowanym modelu pokryły się z późniejszymi badaniami krystalograficznymi oraz ultradźwiękowymi, przeprowadzonymi w laboratorium producenta turbiny. Stwierdzono dużą zgodność uzyskiwanych przez model wyników z pomiarami rzeczywistymi na obiekcie. Ostatecznie sformułowano wnioski dotyczące HAZ i koniecznych modernizacji.

EN

Heat affected zone (HAZ) plays a crucial role both in welding process as well as in different types of cases, that are the consequences from destroy the clearances, bearing liners, journals, etc., that lead to melting and changing in the structure of the material. This phenomenon is accompanied by a significant increase in temperature, which can be caused by an external, either thermal as well as mechanical, source of heat resulting from mutual friction of the surfaces. In order to determine the depth of heat affected zone area and thus find both places of possible phase changes in metal structure, as well as places of plasticity, we performed a series of thermal-FSI numerical simulations. The heat rate sources of the journal surface changing in duration of the phenomenon were taken into account as boundary conditions. In thermal-FSI simulations, there was used the original model implemented in the commercial code, whose task was to estimate temperature field that has been generated during the analyzed case. Further, to determine the depth of the field of plasticity of the metal, there was adapted Burzyński model plasticity. The necessary constants for the model describing the size of the heat generated were experimentally verified. The obtained results in the proposed model agreed with subsequent crystallographic and ultrasound studies, which were conducted in the laboratory turbine manufacturer. It was found good agreement of model results with actual measurements on an object. Suggestions to a proper modernization have been stated, too.