Masters Theses

Date of Award

5-1993

Degree Type

Thesis

Degree Name

Master of Science

Major

Mechanical Engineering

Major Professor

Frank H. Speckhart

Committee Members

Stanley Becker, Grzegorz Kawiecki, Clement Wilson

Abstract

This thesis was a feasibility study of a centrifugal pendulum absorber, designed by Frank H. Speckhart for reducing torsional vibrations in racing engines. Evaluation of this absorber was accomplished in two ways: a simple computer model was established, and the nonlinear equations of motion governing the absorber were solved numerically; and a model and a prototype of the absorber were constructed and tested. The results of the computer simulation of the simple model showed the absorber to significantly reduce torsional vibrations within certain limits of engine torque and speed, which were directly related to the dimensions of the absorber. Outside these limits, the simulation revealed a magnification of torsional vibrations. The simulated performance of the absorber was compared to that of a viscous-fluid damper. The damper provided no significant reduction in torsional vibrations. The prototype absorber test was inconclusive. The model absorber test, which was conducted at a single combination of engine speed and torque, revealed significant reduction in torsional vibrations. For certain operating conditions, there appeared to be a contradiction between the computer and experimental results. This led to the conclusion that the computer model may inadequately have represented a realistic engine system. It was also concluded that the absorber merited further study and testing, having been shown to be very effective under certain conditions. Suggestions were made for additional study and testing of the existing design. Recommendations were given for improvements in the existing design as well.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS