Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (leaf 24). / The purpose of this thesis is the design and manufacture of an electromagnetic recording and playback device. The device was designed to record information onto a steel wire which can replay the signal. The device is of simple mechanical design, resilient to impacts, minor compression, and operator error. The design has a minimal number of parts and requires limited maintenance or replacement of parts. The device is comprised of three systems: a magnetic head, transport system, and a support structure. Each of these systems is described and mechanical drawings for all parts are included. / by Dylan Chavez. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (leaves 31-32). / The Massachusetts Institute of Technology Department of Mechanical Engineering teaches thermodynamics and fluid mechanics through a pair of classes, Thermal Fluids Engineering I & II. The purpose of this project was to design and fabricate a gas-turbine engine for demonstration use in these two classes. The engine was built from an automobile turbocharger with a combustion chamber connected between its compressor and turbine. Pressure and temperature sensors at different points of the engine cycle allow students to monitor the performance of the individual engine components and the complete engine cycle. / by Lauren Tsai. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 52). / This thesis develops a thermodynamic simulation of the melting and solidification of a substance resting on a surface. The simulation was created in an effort to develop a single actuator joint locking and unlocking mechanism for Squishbot. The Squishbot is a proposed robot that has the ability to climb walls and change shape in order to gain entry into normally inaccessible areas. By using COMSOL Multiphysics, a simple model was developed and tested. Under these conditions, the solder melting phase transition took 2.25 seconds to melt and 2.65 seconds to solidify. These results, as well as observations about the behavior of the program's numerical solver, seem to suggest that the proposed joint locking system is feasible. A framework is laid out to proceed with improved and more specific models for use as an optimization tool. / by Robert Utz. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 23-24). / Conducting polymers such as polypyrrole have been the subject of intensive study due to their light weight and useful electrical properties. Many applications of such polymers, such as for use as motor windings or as magnetic field sensors, require a precise knowledge of the electrical properties of the polymers being used. This thesis presents a study of the magnetoresistance of the conducting polymer polypyrrole. It was found that the electrical resistance of polypyrrole wires is not correlated to the strength of a perpendicular magnetic field, but exhibits a large dependence on the operating temperature of the wire. / by Nathaniel Stein Sharpe. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 37). / The design of high school classrooms often does not serve the needs of instructors. The layout of the Boston urban classroom inhibits effective instruction due to physical obstructions and line of sight issues for students. A permanent lab bench commonly found in high school labs creates distance between the lecturing teacher and students. The barrier negatively impacts instruction and classroom management, according to educational literature, observation, and personal experience. The purpose of this project was to design and prototype a solution to retrofit into this classroom. The prototype was designed with the functional requirements of the user, the instructor, in mind. / by Nydia Ruleman. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 14-15). / Horizontal-axis wind turbine designs often included gearboxes or large direct-drive generators to compensate for the low peripheral speeds of the turbine hub. To take advantage of high blade tip speeds, an alternative generator configuration could employ a stator positioned in a shroud on the outside diameter of the turbine.' 7 I performed a preliminary investigation into some of the main design concerns and costs of a shroud-stator turbine. To answer the basic questions of functionality and cost, I considered turbine-blade deflection, material costs, and stator configuration. Although I did not complete the entire investigation, I determined the approximate deflection of the loaded wind turbine blades and developed several relationships between the force and the current output of the turbine for use in designing the stator. / by Nathaniel Shoemaker-Trejo. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 28). / A prototype system was designed and constructed that used a wall-mounted, counterbalanced mechanical arm to support a workspace that can be adjusted for position. Possible applications of the system include use as a writing desk, dynamic toolbox and use supporting home electronics such as computer screens and television screens. The prototype uses gas springs to counterbalance the system against the effects of gravity. The workspace can be raised, lowered, pushed in and out in the horizontal direction and can be rotated about a fixed base. Once a user releases the table the system will maintain that position without additional support. The system has an effective range of 149cm in the horizontal direction, 91cm in the vertical direction and can be rotated in an 180° sweep about the base. / by Chase R. Olle. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Includes bibliographical references (p. 76). / by Ferran A. Ayala. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003. / Includes bibliographical references (leaves 69-70). / by Prasanga D. Hiniduma Lokuge. / S.M.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 213-217). / Improving fuel economy of internal combustion engines is one of the major focuses in automotive industry. The piston ring friction contributes as much as 25% of total mechanical loss in internal combustion engines [1] and is an area of great interests to the automotive industry in their overall effort to improve engine efficiency. However, typical methods to reduce friction loss from piston ring pack, such as ring tension reduction, may cause additional oil consumption. A compromise between reduction of friction loss and control of gas leakage and oil consumption needs to be made, which requires a deep understanding of oil transport mechanism. This compromise gives rise to the interest in modeling work. Both experimental results and previous experience showed that oil film distribution on the piston varies significantly along the circumference and the oil leakage occurs locally. Therefore to predict oil transfer across different ring pack regions, one needs to integrate both global and local processes. This work is aimed at establishing an enduring framework for all the cycle-based processes at different length scales. As a first step, a multi-scale multi-physics piston ring pack model was developed by coupling the structural dynamics of the piston rings with gas flows and local interactions at ring-groove and ring-liner interfaces. A curved beam finite element method was adopted to calculate the ring structural response to interaction between the ring and the liner as well as the ring and the groove. Compared to a traditional straight beam finite element method, the curved beam separates the structural mesh and contact grid by utilizing the shape functions. In this work, a multi-length-scale ring pack model was, for the first time, successfully assembled. This model bears its fundamental values to truly reflect the integral results of all the relevant mechanisms. The significance of the current work is that it demonstrated such an integration of all the length scales is possible for a cycle model with a reasonable computation cost. With the current model, one can realistically investigate the effects of all kinds of piston and liner distortion, piston secondary motion, bridging, and lube-oil dilution on gas sealing, oil transport and lubrication. As a result, optimization of the ring designs and the part of block design contributing to bore distortion can be coordinated to reduce development costs. / by Yang Liu. / Ph. D.