In 2009, Saudi Aramco and KAUST joined to establish the Fuel Combustion for Next Generation Engines (FUELCOM) Program. The objective was to develop an ambitious, long-term collaborative research program between Saudi Aramco's Fuel Technology Team and the Clean Combustion Research Center (CCRC) to enable simulation-based fuel design, with specific focus on advanced engine fuel formulation strategy based on first principles.
Combustion is complex multi-physics phenomena associated with chemical reaction, fluid mechanics, and heat and mass transfer. Chemical and physical properties of the fuel are key to the design and operation of combustion reactors. Fuels have conventionally been rated on a few empirical parameters such as research octane number (RON), motor octane number (MON), derived cetane number (DCN), flash point and boiling range. However, fundamental and first principle-based fuel characterizations can enable high-fidelity predictive engine simulations. The FUELCOM-I program aims to provide such characterizations for conventional and unconventional fuels to aid in the design of future fuel formulations.
The program is divided into five sub-projects with strong interplay and cross-collaboration among the three projects. The first two projects served as short-term pilot projects and were later supplemented by three relatively long-term projects.
Project-specific contact details about basic combustion research are available at the following address:
William Roberts, Ph.D.
1. FUEL SCREENING FOR LOW TEMPERATURE COMBUSTION USING AUTO-IGNITION EXPERIMENTS
During this project, the effect of mixture inhomogeneity on autoignition was investigated and its effect was examined to relate flame behavior with ignition delay times from shock tube experiments and kinetics modeling. Various flames in laminar non-premixed jets were analyzed with coflowing air at elevated temperatures, these include non-autoignited attached and lifted flames, autoignited lifted flames with similar shapes as non-autoignited lifted flames, and autoignited flames with mild combustion when a fuel stream is highly diluted by inert gas.
2. LIQUID HYDROCARBON SOOTING METRIC DEVELOPMENT
One objective of this project is to experimentally and computationally investigate sooting characteristics of gaseous fuels and gasoline surrogate fuels and their blends. Another goal is to produce a database of canonical sooting flames with a variety of gasoline surrogate components and their blends, utilizing a well-defined flame configuration, which is relevant to turbulent sooting flame dynamics in IC engines: The counterflow burner.
3. PHYSICAL PROCESSES OF AUTOIGNITION
The objective of this research program is to experimentally and computationally investigate the physical and chemical kinetic autoignition characteristics of real fuels and their surrogates. The main fuels of interest are gasolines, diesel, naphtha, and lubricant oils. This program utilizes laboratory-scale coflow and counterflow laminar flame configurations developed to operate at high pressures; the fuels will not necessarily be pre-vaporized. These configurations are chosen because they reflect the complexity of autoignition phenomena in real combustion systems, including mixture and temperature inhomogeneity, heat loss and flow field effects, high pressure, and sprays; thus they allow detailed study of the interaction between chemical kinetics, convection, evaporation, and diffusion processes.
4. CHEMICAL KINETICS OF AUTOIGNITION
The goal of this research proposal is to conduct a variety of fundamental chemical kinetic experiments to aid the development of chemical kinetic models. The experiments will be designed to emulate real engine operating conditions and provide information about the transient nature of autoignition phenomenon. The experimental data will be used to validate comprehensive chemical kinetic models that are developed based on a fundamental understanding of fuel combustion chemistry.
5. FLAME SPEEDS OF REAL FUELS
The speed at which premixed laminar and turbulent flames propagate is a fundamental parameter in many combustion applications such as engines and gas turbines. Flame speeds play an important role in their performance and emissions and they influence knocking events in spark-ignited engines. Laminar burning velocity is the governing fundamental physicochemical parameter of the deflagration wave, being indicative of the reactivity, diffusivity and exothermicity of a combustible mixture. As such, laminar burning velocity is an important target data point for validating relevant kinetic mechanisms which describe the combustion of future fuel formulations. Moreover, flame speeds are basic information for virtually all turbulent combustion models, an essential part of developing predictive tools for practical combustion systems. Thus, knowing the laminar and turbulent flame speeds is essential in the modeling and eventual design of efficient engines and predictive computational modeling tool development.