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Dive into the research topics where Michał Wodtke is active.

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Featured researches published by Michał Wodtke.


Journal of Tribology-transactions of The Asme | 2012

Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing

Michał Wodtke; Michel Fillon; Andreas Schubert; Michał Wasilczuk

Part of the heat generated by the shearing of the lubricating film during operation of a hydrodynamic bearing is transferred to the bearing components. In the case of the pad, which is usually fully submerged in the lubricating oil, heat is further transferred at the pad free walls to the oil by convection. This mechanism causes a thermal gradient in a pad and, consequently, its thermal deflection. In large hydrodynamic thrust bearings, thermal deflection of the pads is an important phenomenon influencing bearing performance. For such bearings, pad distortion can reach the level of hydrodynamic film thickness and can significantly change the bearing’s properties. In this paper, the study of the influence of the heat convection coefficient on the predicted performance of a large hydrodynamic thrust bearing is presented. Two sets of convection coefficients at the pad free surfaces are investigated with the use of thermo-elasto-hydrodynamic (TEHD) calculations. An analysis is carried out for the Itaipu hydro turbine thrust bearing with the outer diameter equal to 5.2 m, which is one of the biggest hydro power plants in the world. The results of the theoretical predictions are compared to the measured data collected during bearing operation.


Tribology Transactions | 2009

Structural Properties of Foil Bearings: A Closed-Form Solution Validated with Finite Element Analysis

Piotr Hryniewicz; Michał Wodtke; Artur Olszewski; Romuald Rzadkowski

Fluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the bump foil-top foil assembly and the interaction between bumps and which can predict the bearing deflection and stresses due to an arbitrary pressure load. The proposed model is first validated using a finite element analysis and the results available in the literature and then used to conduct a parametric study investigating the influence of bump foil geometry, the coefficient of friction between the bearing components, and the type of loading on the structural properties of the bearing. The most important parameters are also identified. The proposed analytical model is completely algebraic and can be easily implemented using any programming language, a spreadsheet, or even a calculator. The resulting solution can also be coupled with the appropriate hydrodynamic model to predict static performance of compliant foil bearings.


Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology | 2013

Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems

Michał Wodtke; Artur Olszewski; Michał Wasilczuk

Fluid–structure interaction technique seems to be one of the most promising possibilities for theoretical analysis of lubrication problems. It allows coupling of different physical fields in one computational task, taking into account the interaction between them. In this article, two sets of fluid–structure interaction analyses focusing on the bearing performance evaluation are presented. One analysis was applied to a water-lubricated journal bearing and the other to a hydrodynamic thrust bearing lubricated with oil. Steady-state operation was considered in both cases. In the presented cases of fluid–structure interaction analyses, all important phenomena accompanying bearing operation are considered, e.g. lubricant flow, structure movements and their deformations as well as heat transfer in case of thrust bearing. The problems encountered during modelling are discussed in this article, as well as the results of calculations: hydrodynamic pressures, gap geometries or temperature profiles.


Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology | 2014

Simulation of large thrust-bearing performance at transient states, warm and cold start-up

Piotr Pajączkowski; Andreas Schubert; Michał Wasilczuk; Michał Wodtke

The start-up of a large hydrodynamic thrust bearing of a vertical hydrogenerator is one of the most critical situations during the lifetime of a bearing. Hydrodynamic load capacity is low due to low speed and higher thermal deformations of the pad. A new approach to the simulation of a hydrodynamic bearing is shown in this article. A combination of finite elements method and computational fluid dynamics is used to perform the transient simulation of the bearing start-up. A bidirectional bearing of a pump-storage power plant is investigated. To show the potential advantages of the new method, a comparison of the warm and cold start procedure is presented. The thermal crowning of the bearing pad, oil film gap and other parameters of both cases are compared in this article.


Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology | 2014

Large hydrodynamic thrust bearing: Comparison of the calculations and measurements

Michał Wodtke; Andreas Schubert; Michel Fillon; Michał Wasilczuk; Piotr Pajączkowski

Hydrodynamic thrust bearings, used to carry axial loads in heavily loaded shafts of water power plants hydro turbines, can reach outer diameters even exceeding 5 m. In such large objects scale effect could be observed. According to this, allowable bearing specific load assuring safe operation of the bearings has to be decreased, which increases thrust bearing dimensions. This effect is caused by excessive thermal deflections of bearing pads, which significantly change oil gap geometry, and in consequence, decreases bearing load-carrying ability. Design of hydrodynamic thrust bearing of large dimensions seems to be a demanding engineering challenge, and additional difficulty comes from limited possibilities of experimental testing of these systems due to high costs. Theoretical investigations, carried out with the use of specially developed computer models, remain a feasible alternative for experimental research. But the accuracy of the models is not often directly validated, because of the lack of appropriate experimental data coming from large objects. In this paper, results of calculations carried out for a large hydrodynamic thrust bearing are shown and compared to measurement data obtained at bearing commissioning stage. Pad temperatures profile sliding surface, oil pressure in hydrodynamic gap and film geometry are compared to the measured values. According to the presented comparisons, some conclusions are drawn with respect to the accuracy of models used to predict large thrust bearing performance.


Key Engineering Materials | 2011

Influence of Shaft Misalignment on Water Lubricated Turbine Sliding Bearings with Various Bush Modules of Elasticity

Wojciech Litwin; Artur Olszewski; Michał Wodtke

Hydropower industry increasingly frequently uses water lubricated bearings in turbines. This stems from the lack of negative impact of such solution on the environment. The paper presents an analysis of the influence of shaft misalignment in a turbine with water lubricated main shaft bearing on its hydrodynamic capacity. The theoretical analysis was based on the results of calculations for experimentally verified elastohydrodynamic lubrication (EHL) model. The obtained results showed impact of the stiffness of bush material and the degree of misalignment on bearings hydrodynamic capacity.


Key Engineering Materials | 2011

Experimental Investigation of Prototype Water-Lubricated Compliant Foil Bearings

Artur Olszewski; Michał Wodtke; Piotr Hryniewicz

First gas-lubricated compliant foil bearings (CFBs) were built in the 1950s. Due to their significant advantages, such as oil-free operation, good tolerance to bearing misalignment and very low maintenance, they have been penetrating the bearing applications for high speed compressors, air-cycle machines and gas turbines. The work presented here investigates a novel idea of water-lubricated compliant foil bearings, which could be used in applications where environmentally friendly lubrication is desired, for example in hydroelectric turbines or water pumps. Experimental results collected for three prototype water-lubricated foil journal bearings are presented. The tests were conducted under steady radial load and with the sliding speed varied incrementally. A sequence of design improvements is presented, with the best bearing demonstrating friction coefficient of about 0.01 at the sliding speed of about 4 m/s and the radial load of about 300 kPa. Encountered difficulties, research methodology and the testing equipment are also described.


Tribology Transactions | 2015

Centrally Pivoted Tilting Pad Thrust Bearing with Carbon-Based Coated Collar—Experimental Results of Low- and Medium-Speed Operation

Michał Wasilczuk; Michał Wodtke; Wolfgang Braun

Experimental results of the research on a tilting pad thrust bearing with symmetrical pad support in the conditions of high loads and low speeds are presented in the paper. As described in the literature review, experimental results of tilting pad bearings at low speed/high load regime and transient conditions are rare. Unusual material selection - steel pad against a DLC-type coating on the collar was utilized. Such material combination has been mostly used in automotive industry in concentrated contact friction pairs, but it is not commonly used in thick film contacts. The tests included low speed high load and a test, where a Stribeck curve was reproduced. The steel pads showed minimum traces of contact and no visible wear was noticed on the collar coating. Differences of operation in medium and low speed were observed. Big variations of bearing temperature at medium speed and almost constant pad temperature at low speed were measured. At a specific load of 5 MPa transition to mixed friction was occurring at a sliding speed of approx. 0.18 m/s.


Polish Maritime Research | 2018

FEM Analysis and Experimental Tests of Rigid Riser Hanging System

Artur Olszewski; Michał Wodtke; Artur Wójcikowski

Abstract The article presents the analysis, project, and experimental examination of an original rigid riser for Coil Tubing Pipes. The principle of riser operation is based on the use of friction forces. The research included the FEM analysis of the designed riser, calculations of the required bolt tensions, and checking the effect of the clamping force on stress distribution in the pipeline. The results of computer simulation were verified on a specially designed test rig. The described riser design was implemented on the LOTOS Petrobaltic platform, thus eliminating the need for purchase and installation of expensive elastic risers.


ASME/STLE 2012 International Joint Tribology Conference | 2012

New Generation of Water Lubricated Foil Bearing: Numerical Models and Experimental Verification

Artur Olszewski; Michał Wodtke; R. Gawarkiewicz

The paper presents a new idea of foil water-lubricated bearing and the methodology of hydrodynamic characteristics calculations. Two different computer models were built in order to assess the theoretical characteristics of these bearings. Firstly a structural model coupled with a hydrodynamic fluid model which takes into account: fluid flow in the deformed fluid gap — a specific design of bearing support and the friction in bearing support. The second model is based on the fluid structure interaction simulation. Due to the fact that it is necessary to define physical properties of the materials for computer models, special tribology and stiffness tests of actual materials intended to be used in the prototype bearing were performed.The test rig was modernised by installing pressure sensors on bush perimeter in two parallel planes in order to verify the method of the calculation of the bearing.Copyright

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Michał Wasilczuk

Gdańsk University of Technology

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Artur Olszewski

Gdańsk University of Technology

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Grzegorz Rotta

Gdańsk University of Technology

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Leszek Dąbrowski

Gdańsk University of Technology

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Piotr Hryniewicz

Polish Academy of Sciences

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P. Pajączkowski

Gdańsk University of Technology

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R. Gawarkiewicz

Gdańsk University of Technology

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