Engineering Commons^™

Analysis Of Connecting Rod Bearing Design Trends Using A Mode-Based Elastohydrodynamic Lubrication Model, Travis M. Blais

Theses

Available design trends for big end connecting rod bearings utilize widely adopted rapid methods for prediction of minimum film thickness due to their superior speed and ease of use. However, they impose unrealistic assumptions such as surface rigidity, which could compromise the accuracy of results. The significance of structural elasticity and updated models was investigated using a mode based elastohydrodynamic lubrication model which includes body forces, mass conserving cavitation, and surface roughness. Eight physical connecting rods were modeled using finite element methods and simulated over a variety of conditions, varying engine speed, bearing clearance, and oil viscosity. The results show …

Active Noise Control Using Adaptive And Advanced Control Techniques, Michael O'Brien

Theses

The theory and application of Active Noise Control to remove irritating acoustic pollution from a variety of sources has and continues to receive significant attention from both theoreticians and practitioners.

While a classical acoustic noise problem is the rejection of acoustic tonal disturbances with the most common solution employed being the celebrated filtered-X LMS algorithm, this thesis shows that the presence of non-linearly induced harmonics at multiple frequencies of the original tone often results in poor performance of this algorithm. It is further found that the noise reduction at these problematic harmonics can be improved in a number of ways, …

Effect Of Center Of Gravity Location On Optimum Performance Of Random Vibratory Vehicle Suspension, Daniel Mahar

Theses

This study provides the analysis for the optimal design of a conventional vehicle suspension system, consisting of a sprung mass (vehicle body) and two unsprung masses (wheel frame), accentuated by the implementation of a damped absorber to the unsprung masses. Further, the effect of the c.g. (center of gravity) location of the vehicle body is investigated. A two dimensional, four degrees of freedom linear model is chosen. Randomly profiled terrain is assumed to impart hyperbolically distributed stationary vertical random displacements to the front and rear wheels. For generalization, nondimensional design parameters are selected. Criteria for optimization include the tire-terrain normal …