Date of Award

2016

Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Jeffrey Naber

Committee Member 1

Jaclyn Johnson

Committee Member 2

David Wanless

Abstract

The U.S. Army and many NATO affiliates have adopted a ‘one fuel forward fuel policy’ (OFF). The goal of the OFF policy is reducing the logistics and cost involved with providing fuel for military vehicles. With this policy, the logical choice fuel is military grade jet petroleum, JP-8, because of the fuel constraints of turbo-jet engines. This requirement has made it necessary to run military compression ignited engines on JP-8. To reduce the Army’s reliance on petroleum based fuels an alternative fuel, synthetic JP-8, derived from coal and made in the Fischer-Tropsch production method is allowed to be blended up to 50% with JP-8. The two fuels have varying cetane numbers of for 43.1 for JP-8 and 25 for the synthetic JP-8 which influence combustion characteristics. Therefore, the goal of the current work is to characterize the ignition characteristics of synthetic JP-8 as compared to the reference JP-8 under the same test conditions. A JP-8 surrogate fuel is also developed and compared against the baseline fuel in terms of both ignition behavior and liquid penetration. Testing is conducted in an optically accessible combustion vessel sweeping ambient temperatures and densities of 800 – 1100 K and 7.3 – 30.2 kg/m3, respectively. The resultant data is used in comparison of all three fuels in ignition delay and steady state liquid penetration characteristics. Correlations are also developed for calculating the ignition delay of both the JP-8 and the synthetic JP-8 fuel and is used to compare to the surrogate fuel and to compare to a pool of data from past work on JP-8. Results of these comparisons show a 50% increase in the ignition delay and a 10% shorter steady state liquid penetration of the low cetane value synthetic JP-8 over the baseline JP-8 fuel sample. Findings also show the surrogate matches the baseline fuel to within 10% for ignition delays but it over penetrates the baseline fuel by around 30% for liquid penetration.

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