Semester

Summer

Date of Graduation

2003

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Nigel N. Clark.

Abstract

A time based numerical simulation program was built at West Virginia University to simulate the operation of a two-stroke compression ignition direct injection linear engine. The two-stroke linear engine consists of two pistons connected together with a yoke and allowed to move freely according to the frequent combustion that takes place in response to fueling and load applied along the full stroke of the internal combustion engine. The simulating program used a series of dynamic and thermodynamic equations that were solved simultaneously to predict the performance and analyze the different factors affecting the operation of the two-stroke compression ignition linear engine coupled with linear alternator. This dissertation presents a dimensionless analysis parametric study to explore this novel type of internal combustion engine. It was found that these types of engines have a nature to build up compression ratio, and this was the reason behind recommending to operate such engines with high air to fuel ratios. Indicated efficiency was found to have an average of 42%. For stationary power generation a bore to effective stroke ratio equal to 1, or 1.3 would result in an efficient power generation unit whereas a bore to effective stroke length equal to three or four would result in a high-indicated power per cylinder volume, which may be suitable for automotive application. It was also found that a bore to effective stroke length of 2.2 would result in excessive compression ratio. This makes such a design limited to special applications where high indicated power per generator mass is needed. Advancing fuel injection close to the cylinder head during the compression stroke and burning the fuel with premixed to diffusive combustion ratio of 20% to 80% would enhance indicated efficiency and indicated power generated relative to injecting the fuel far from the cylinder head during the compression stroke and burning the fuel with premixed to diffusive combustion ratio of 40% to 60%.

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