Development of Resonating Tubular Oscillating Linear Alternator and Engine; System Design and Modeling

Abstract

A resonating tubular oscillating linear alternator and engine (OLEA) provides an alternative for electric power generation to conventional rotary alternator and engine systems. An OLEA allows direct conversion of linear reciprocating motion provided by a free piston internal combustion engine to electricity. The elimination of the engine crankshaft and bearing allows a design that is more compact and more efficient with fewer moving parts. Additionally, mechanical resonance is utilized to further enhance the performance, power density and efficiency of the system. Presented in this thesis is a study of a resonating tubular OLEA system. Electrical performance has been recorded for two different stator configurations, an air core stator and an iron core stator. Electrical performance comparisons are made to finite element modeling (FEMM/LUA scripting) results using Fourier expansion and a simplified equivalent model with good results. A higher power design of OLEA and its two stator configurations was also modeled and its performance has been predicted. In addition, some of the mechanical considerations for the free piston OLEA is included. It was found that mechanical offset of the translator and operation at large stroke lengths cause distortion of the alternator output voltage.