Modeling of piston secondary dynamics and tribology

Date

1992-06-01

Author

Keribar, Rifat
Dursunkaya, Zafer

Metadata

Show full item record

Item Usage Stats

175
views

0
downloads

This paper describes a general, design-oriented model for the analysis of secondary motions in conventional and articulated piston assemblies. The model solves for the axial, lateral and rotational departures in positions and motions from the nominal kinematics, resulting from clearances within the piston assembly and also between the piston assembly components and the cylinder. In order to accurately represent the effect of oil films, the model includes comprehensive treatments of hydrodynamic and boundary lubrication of the skirt and of wristpin bearings. The skirt lubrication submodel also allows representation of oil starvation at the cylinder end of the skirt. The methodology allows the characterization of conventional and articulated piston secondary motions in the thrust plane of the cylinder. Oil and contact pressure and film thickness distributions in skirt-bore and wristpin interfaces are also solved for. Motions of the piston, pin, rod and (for articulated pistons) skirt are separately calculated, by integrating equations of motion for individual components and dynamic degrees of freedom. Various configurations with respect to rigid attachment of the wristpin to other components can also be represented. In the equations of motions solved, all gas pressure, inertia, friction and oil or contact pressure forces are accounted for. All pertinent operating parameters (engine speed and cyclic pressure variation) as well as design parameters, such as component masses, moments of inertia, mass centers, pin offsets, skirt profile, roughness and lubricated area, bore distortion etc. are specifiable to the model as inputs. The integrated model was applied in a number of parametric studies, to conventional and articulated pistons. Effects of speed, load and piston configuration as well as viscosity, skirt design and profile were investigated. Results indicate that the skirt friction predictions of the model correspond to known levels and trends. Further, design parameters such as nominal clearance, skirt profile, circumferential lubrication extent as well as oil viscosity are shown to have key influences on the action of the oil films and thereby on piston motions and skirt friction.

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0026880252&origin=inward
https://hdl.handle.net/11511/84861

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Simulation of Secondary Dynamics of Articulated and Conventional Piston Assemblies Dursunkaya, Zafer (1992-01-01) This paper describes a general model for the analysis of secondary motions in conventional and articulated piston assemblies. The model solves for the axial, lateral and rotational departures in positions and motions from the nominal kinematics, resulting from clearances within the piston assembly and also between the piston assembly components and the cylinder. The methodology allows the characterization of conventional and articulated piston secondary motions in the thrust plane of the cylinder. Motions o...
Analysis of thin walled open section tapered beams using hybrid stress finite element method Akman, Mehmet Nazım; Oral, Süha; Department of Mechanical Engineering (2008) In this thesis, hybrid stress finite element is formulated for the analysis of the isotropic, thin walled, open section beams with variable cross sections. The beam element has two nodes each having seven degrees of freedom. Assumption of stress field is sufficient to determine the element stiffness matrix. Axial, flexural and torsional effects are taken into account in the analysis. The methodology can be applied both to the tapered and the uniform beams. Throughout this study, firstly element cross-sectio...
Modeling of the nonlinear behavior of steel framed structures with semi rigid connections Sarıtaş, Afşin; Özel, Halil Fırat (null; 2015-07-21) A mixed formulation frame finite element with internal semi-rigid connections is presented for the nonlinear analysis of steel structures. Proposed element provides accurate responses for spread of inelasticity along element length by monitoring the nonlinear responses of several crosssections, where spread of inelasticity over each section is captured with fiber discretization. Each material point on the section considers inelastic coupling between normal stress and shear stress. The formulation of the ele...
Consideration of spatial variation of the friction coefficient in contact mechanics analysis of laterally graded materials Dağ, Serkan (2016-01-01) This paper presents a new analytical approach for sliding contact analysis of laterally graded materials, which allows taking into account the spatial variation of the friction coefficient. The method is developed by considering a sliding frictional contact problem between a laterally graded elastic medium and a rigid flat punch. Governing partial differential equations entailing the displacement components are derived in accordance with the theory of plane elasticity. General solutions are determined and b...
Modeling and implementation of local volatility surfaces in Bayesian framework Animoku, Abdulwahab; Uğur, Ömür; Yolcu-Okur, Yeliz (2018-06-01) In this study, we focus on the reconstruction of volatility surfaces via a Bayesian framework. Apart from classical methods, such as, parametric and non-parametric models, we study the Bayesian analysis of the (stochastically) parametrized volatility structure in Dupire local volatility model. We systematically develop and implement novel mathematical tools for handling the classical methods of constructing local volatility surfaces. The most critical limitation of the classical methods is obtaining negativ...

Citation Formats

R. Keribar and Z. Dursunkaya, “Modeling of piston secondary dynamics and tribology,” 1992, Accessed: 00, 2021. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0026880252&origin=inward.