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Search results for: FRICTION LAYER
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Numerical Study of Turbulent Flow and Heat Transfer of Nanofluids in Pipes
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (Reynolds number between 6000 and 12000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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Friction and Lubrication of Large Tilting-Pad Thrust Bearings
PublicationFluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due...
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Effective Friction Angle Of Deltaic Soils In The Vistula Marshlands
PublicationThis article presents the results of laboratory tests on soft, normally consolidated soils from the Vistula Marshlands. Samples of high-plasticity organic soils (muds) taken from 3.2–4.0 m and 9.5–10.0 m depth, as well as peat deposit at 14.0 m, are analysed. Presented case study confirms the applicability of the Norwegian Institute of Technology (NTH) method based on Cone Penetration Tests (CPTU) and allows for a conservative...
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Strength parameters of deltaic soils determined with CPTU, DMT and FVT
PublicationThis paper presents the results of soil investigation in soft, normally consolidated organic soil in the estuary of Vistula river. The analysis concerns clayey mud and peat layers interbedded with loose to medium-dense sands. Several Cone Penetration Tests with pore water measurement (CPTU), Dilatometer Tests (DMT) and Field Vane Tests (FVT) were performed on the testing site. The cone factor Nkt was estimated using the results...
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Drivetrain of a Wind Turbine
PublicationIn a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplying gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration...
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UKŁAD PRZENIESIENIA NAPĘDU TURBINY WIATROWEJ
PublicationIn a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplicating gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration of the lectures.
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Centrally Pivoted Tilting Pad Thrust Bearing with Carbon-Based Coated Collar—Experimental Results of Low- and Medium-Speed Operation
PublicationExperimental 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...
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CPTU/DMT control of heavy tamping compaction of sands
PublicationHeavy tamping compaction method in cohesionless alluvial soil was evaluated with CPTU and DMT tests. Some examples of interpretation of soundings in pre-treated and compacted sands are given. The compaction work was performed in two stages. Compaction control was performed after each stage of tamping. Additional tests were performed two weeks after the compaction works completion to study the set-up effect. While typical increase...
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Turbulence model evaluation for numerical modelling of turbulent flow and heat transfer of nanofluids
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (Reynolds number between 6000 and 12000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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Numerical study of turbulent flow and heat transfer of nanofluids in pipes
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (6 000 < Re < 12 000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data of Vajjha et al. [1]. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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Investigation of Mechanical and Microstructural Properties of Welded Specimens of AA6061-T6 Alloy with Friction Stir Welding and Parallel Friction Stir Welding Methods
PublicationThe present study investigates the effect of two parameters of process type and tool offset on tensile, microhardness, and microstructure properties of AA6061-T6 aluminum alloy joints. Three methods of Friction Stir Welding (FSW), Advancing Parallel-Friction Stir Welding (AP-FSW), and Retreating Parallel-Friction Stir Welding (RP-FSW) were used. In addition, four modes of 0.5, 1, 1.5, and 2 mm of tool offset were used in two welding...
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Contact with coupled adhesion and friction: Computational framework, applications, and new insights
PublicationContact involving soft materials often combines dry adhesion, sliding friction, and large deformations. At the local level, these three aspects are rarely captured simultaneously, but included in the theoretical models by Mergel et al., (2019). We here develop a corresponding finite element framework that captures 3D finite-strain contact of two deformable bodies. This framework is suitable to investigate sliding friction even...
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Tribo-Environment Dependent Chemical Modification of Sliding Interfaces in Ultrananocrystalline Diamond Nanowall Film: A Correlation with Friction and Wear
PublicationTribological properties of ultrananocrystalline diamond nanowall (UNCD NW) films were investigated quantitatively in three different and controlled tribo-environmental conditions, proposing the passivation and graphitization mechanisms. However, these mechanisms are rather complicated and possibly can be understood in well-controlled tribological conditions. It was shown that the friction and wear of these films were high in highPage 1...
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Preparation and Characterization of Diamond-like Carbon Coatings for Biomedical Applications—A Review
PublicationDiamond-like carbon (DLC) films are generally used in biomedical applications, mainly because of their tribological and chemical properties that prevent the release of substrate ions, extend the life cycle of the material, and promote cell growth. The unique properties of the coating depend on the ratio of the sp3/sp2 phases, where the sp2 phase provides coatings with a low coefficient of friction and good electrical conductivity,...
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Discussion on “Coupled effective stress analysis of insertion problems in geotechnics with the Particle Finite Element Method” by L. Monforte, M. Arroyo, J.M. Carbonell, and A. Gens
PublicationAddressed here is the Particle Finite Element Method (PFEM) modelling of undrained CPTu penetration with regard to a reference analytical solution based on the Spherical Cavity Expansion Method (SCEM). Also discussed is the choice of the soil model and its parameters. The effect of cone interface friction on CPTu simulation is analyzed in a series of penetration tests using Arbitrary Lagrangian-Eulerian (ALE) and Updated Lagrangian...
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Should we seek further improvement of fluid film bearings - what for and how?
PublicationFluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient. Large bearings supporting shafts of huge and important rotating machines constitute a special group of fluid film bearings since the reliability of crucial systems, like for example electro-energetic system, rely on their trouble-free operation. Large thrust bearings, apart from enormous...
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Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
PublicationBabbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance...
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Effects of Noncontact Shoulder Tool Velocities on Friction Stir Joining of Polyamide 6 (PA6)
PublicationIn this study, the effects of the traverse and rotational velocities of the noncontact shoulder tool on the heat generation and heated flux during the friction stir joining of high-density polyamide 6 (PA6) polymer were investigated. The computational fluid dynamics (CFD) method was employed to simulate the thermomechanical phenomena during the friction stir joining (FSJ) process of PA6. A developed model was used to consider the...
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Experimental comparison of the transition speed of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationA journal bearing test bench is used to find the transition speed between the hydrodynamic and mixed lubrication regimes for a modified magnetorheological (MR) fluid. It is shown that the transition speed of the bearing can be reduced by applying a local magnetic field near minimum film when it is lubricated with the MR fluid, and that this will only marginally increase friction. The lubricating performance of the MR fluid is compared...
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Experimental and analytical thermal study of PTFE composite sliding against high carbon steel as a function of the surface roughness, sliding velocity and applied load
PublicationThis study investigates the contact temperatures caused by frictional heating of sliding parallel pairs. In this case the materials studied are a PTFE composite in contact with a high carbon steel plate. These materials are commonly used for industrial applications, in particular as the main contacting components within a scroll expander system. The expected contact temperature values are important to be quantified in order to...
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FEM ANALYSIS AND EXPERIMENTAL TESTS OF RIGID RISER HANGING SYSTEM
PublicationThe 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...
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A case study of robust sliding mode control applied to inverted pendulum on a cart
PublicationA control problem of an inverted pendulum on a cart has been addressed in this paper. In particular, a synthesis of alternative sliding mode control for stabilisation of an inverted pendulum at an upper equilibrium point has been investigated. Hence, the feasibility of implementing the developed control system, taking into account primarily the friction of the cart against the gantry and the limited length of the gantry, in a real...
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THEORETICAL AND EXPERIMENTAL INVESTIGATION OF THIN-WALLED BEARING SHELL’S DESIGN PARAMETERS AND ASSEMBLY CONDITIONS ON THE HOLDING TORQUE INSIDE A HOUSING BORE OF A CONNECTING ROD
PublicationThe aim of the work was the experimental and theoretical evaluation of the influence of the most important parameters determining the holding torque of a thin-walled bearing shell inside a housing bore of a connecting rod. The main investigated parameters were defned by authors experience in this feld. In the frst stage of research, a special test stand was designed in order to allow measuring the real values of the friction torque...
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Wear in siding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specim. sets #20-#21, #22-#23, #24-#25, #26-#27, #28-#29,#30 - #31. Run time: 4-8h.
Open Research DataWear in sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer.Running time: 4-8h.Specimen sets:Specim. sets (# [upper, rotating] - #[lower, non-rotating]):#20-#21, #22-#23, #24-#25, #26-#27,...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #24 - #25.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #24 (upper, rotating), #25 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #28 - #29.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #28 (upper, rotating), #29 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Wear in siding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specim. sets #20-#21, #22-#23, #24-#25, #26-#27, #28-#29,#30 - #31. Run time: 0-4h.
Open Research DataWear in sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer.Running time: 0 - 4h.Specimen sets:Specim. sets (# [upper, rotating] - #[lower, non-rotating]):#20-#21, #22-#23, #24-#25, #26-#27,...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #30 - #31.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #30 (upper, rotating), #31 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #20 - #21.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #20 (upper, rotating), #21 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #22 - #23.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #22 (upper, rotating), #23 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #28 - #29.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #28 (upper, rotating), #29 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Specimen running-in. Prep. to sliding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specimen set #26 - #27.
Open Research DataSpecimen running-in procedure. Preparation to sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. Specimen set #26 (upper, rotating), #27 (lower, non-rotating)CZ_PRZYS.MAT - accelerometerMOM_TAR.MAT...
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Research on water lubricated main shaft bearings in conditions of improper lubrication and cooling conducted on high torque real-life scale bush test rig
PublicationWater lubricated polymer bushes find increasingly popular use in the sliding bearings of marine propellers, water turbines and pump shafts. Such popularity is partly due to their simple construction which also means relatively affordable price. In addition, properly designed and installed water lubricated bearings may well last for over a decade. However, in practical experience one may also observe cases of rapid wear...
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Multi Parameter Sliding Test Result Evaluation for The Selection of Material Pair for Wear Resistant Components of a Hydraulic motor Dedicated for Use With Environmentally Friendly Working Fluids
PublicationIn the paper the method and results are presented of the testing of tribological performance of a number of hard materials available commercially. The tests consisted in unidirectional sliding with liquid lubrication. The load and velocity regime chosen were similar to a standard four-ball lubricity test with constant velocity and load increasing over time. The regime was modified in such a way that over the initial part of the...
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Alternative convolution approach to friction in unsteady pipe flow
PublicationIn the paper some aspects of the unsteady friction in pipe flow expressed by the convolution are analyzed. This additional term introduced into the motion equation involves the accelerations of fluid occurring in the past and a weighting function. The essence of such approach is to assume the appropriate form of weighting function. However, until now no fully reliable formula for this function has been found. To avoid some inconveniences...
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Thermo-Mechanical Simulation of Underwater Friction Stir Welding of Low Carbon Steel
PublicationThis article investigates the flow of materials and weld formation during underwater friction stir welding (UFSW) of low carbon steel. A thermo-mechanical model is used to understand the relation between frictional heat phenomena during the welding and weld properties. To better understand the effects of the water environment, the simulation and experimental results were compared with the sample prepared by the traditional friction...
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Effect of processing parameters on the cyclic behaviour of aluminium friction stir welded to spark plasma sintered aluminium matrix composites with bimodal micro-and nano-sized reinforcing alumina particles
PublicationUnderstanding the cyclic behaviour of Alumina reinforced Aluminium composites (Al-A2O3) was of critical importance, for their further application in the different industrial sectors. The present study is focussing on the cyclic behaviour of the Al-Alumina nanocomposite produced through the combination of spark plasma sintering (SPS) method and friction stir welding (FSW). The added Alumina with total content of 10% is the combination...
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Dynamics of a linear pneumatic actuator with 80 mm piston diameter and 500 mm stroke subjected only to a mass load of 2570 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 63 mm piston diameter and 500 mm stroke subjected only to a mass load of 1640 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 63 mm piston diameter and 150 mm stroke subjected only to a mass load of 750 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 80 mm piston diameter and 150 mm stroke subjected only to a mass load of 1100 g
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Dynamics of a linear pneumatic actuator with 50 mm piston diameter and 150 mm stroke subjected only to a mass load of 1530 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 80 mm piston diameter and 100 mm stroke subjected only to a mass load of 1650 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 63 mm piston diameter and 100 mm stroke subjected only to a mass load of 1640 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 80 mm piston diameter and 300 mm stroke subjected only to a mass load of 1650 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 50 mm piston diameter and 100 mm stroke subjected only to a mass load of 930 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 50 mm piston diameter and 300 mm stroke subjected only to a mass load of 930 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 80 mm piston diameter and 150 mm stroke subjected only to a mass load of 1650 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 50 mm piston diameter and 100 mm stroke subjected only to a mass load of 450 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....
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Dynamics of a linear pneumatic actuator with 50 mm piston diameter and 500 mm stroke subjected only to a mass load of 1530 g
Open Research DataThe aim of the study was to determine the dynamics of a linear pneumatic cylinder subjected only to mass load. An actuator of one of the well known European manufacturers was tested.The experiment were to measure pressure changes in both chambers of the actuator and the position of the piston during stroke and retracting. The test was repeated 11 times....