Access Type

Open Access Dissertation

Date of Award

January 2013

Degree Type


Degree Name



Mechanical Engineering

First Advisor

Naeim A. Henein


The aim of this research is to investigate the effect of air inlet temperature and boost pressure on the auto-ignition of fuels that have different CNs and volatilities in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C at a constant intake pressure of 1.1 bar. The boost pressure is varied from 1.1 bar to 1.5 bar at a constant intake temperature of 60°C. All engine tests are run at steady-state conditions. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 50 & 31) and F-T SPK. Detailed analysis is made of the rate of heat release during the ignition delay period, to determine the effect of fuel volatility and CN on the auto-ignition process. A STAR-CD CFD model is applied to track the effect of intake temperature and pressure on fuel evaporation, start of exothermic reactions, formation of different species and their significance in the auto-ignition process. CHEMKIN is used to study the chemical reactions under different equivalence ratio, pressure and temperatures. Special attention has been given to LT (low-temperature) and NTC (negative-temperature coefficient) regimes during the ignition delay period. Effect of intake pressure and temperature on these regimes has been studied in detail.