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Tian Tian. McNally, Conor P. (Conor Peter), 1975- Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2005-09-06T20:37:57Z 2005-09-06T20:37:57Z 2000 2000 http://hdl.handle.net/1721.1/26880 46310081 Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000. Includes bibliographical references (leaves 100-101). The reciprocating motion of the piston of an internal combustion engine in the vertical plane is referred to as its primary motion, and it is this primary motion that produces power in the engine. Due to the fact that there is a clearance between the piston and the liner, and that certain forces on the piston have components in the horizontal direction, there exists some lateral motion of the piston and also some rotational motion about the wrist pin axis. This motion is referred to as secondary motion. Secondary motion has significant implications for oil transport past the piston ring-pack, engine friction and engine noise. For these reasons a comprehensive numerical model of secondary motion is a valuable tool for engine designers and development engineers. This work involves the development of a comprehensive and robust computer model of piston secondary motion, which can be easily run on a desktop computer. The model is applicable to both conventional mono-piston assemblies and also to articulated piston assemblies. The modeling approach involves treating the piston assembly as a set of independent rigid bodies, and formulating and solving the equations of motion for each body. The hydrodynamic skirt-liner interaction force is computed by solving the Reynolds equation for the oil film and integrating the computed pressure. This essentially one dimensional calculation is performed at several circumferential locations on the piston, and the results are integrated to yield a single force in the main thrust-anti thrust direction. The model is first developed with a basic form of this hydrodynamic calculation, which is later improved to include a solution for the wetted region and a complete pressure distribution on the piston. Results using both forms of the model are compared and analyzed, and the final model is used to perform several parametric studies involving various engine operating parameters. by Conor P. McNally. S.M. 107 leaves 4738982 bytes 4751778 bytes application/pdf application/pdf en_US Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Development of a numerical model of piston secondary motion for internal combustion engines Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="96178d3d-2638-4d7e-b6fa-cffa0929823c"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>en_US</Language> <Title>Development of a numerical model of piston secondary motion for internal combustion engines</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2000</PublicationDate> <Authors> <Author> <DisplayName>McNally, Conor P. (Conor Peter), 1975-</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>The reciprocating motion of the piston of an internal combustion engine in the vertical plane is referred to as its primary motion, and it is this primary motion that produces power in the engine. Due to the fact that there is a clearance between the piston and the liner, and that certain forces on the piston have components in the horizontal direction, there exists some lateral motion of the piston and also some rotational motion about the wrist pin axis. This motion is referred to as secondary motion. Secondary motion has significant implications for oil transport past the piston ring-pack, engine friction and engine noise. For these reasons a comprehensive numerical model of secondary motion is a valuable tool for engine designers and development engineers. This work involves the development of a comprehensive and robust computer model of piston secondary motion, which can be easily run on a desktop computer. The model is applicable to both conventional mono-piston assemblies and also to articulated piston assemblies. The modeling approach involves treating the piston assembly as a set of independent rigid bodies, and formulating and solving the equations of motion for each body. The hydrodynamic skirt-liner interaction force is computed by solving the Reynolds equation for the oil film and integrating the computed pressure. This essentially one dimensional calculation is performed at several circumferential locations on the piston, and the results are integrated to yield a single force in the main thrust-anti thrust direction. The model is first developed with a basic form of this hydrodynamic calculation, which is later improved to include a solution for the wetted region and a complete pressure distribution on the piston. Results using both forms of the model are compared and analyzed, and the final model is used to perform several parametric studies involving various engine operating parameters.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>