Download Free Shock Tube Studies Of Biofuel Kinetics Book in PDF and EPUB Free Download. You can read online Shock Tube Studies Of Biofuel Kinetics and write the review.

The harmful emissions associated with the combustion of fossil fuels combined with the rapidly increasing global demand for energy present serious challenges to the long term sustainability of life on this planet. Fossil fuels currently account for approximately 81% of worldwide energy usage, and approximately 22% of global energy consumption occurs in the transportation sector. One approach for addressing the world's energy challenges is to reduce the consumption of fossil fuels by improving the numerical simulation capabilities of combustion systems, thus enabling engineers to design more efficient combustion devices. A prerequisite for this design capability is the understanding of chemical kinetics of the fuels that are being utilized. An alternative approach for reducing the consumption of fossil fuels is developing renewable energy alternatives that eliminate the need for fossil fuels altogether. Biofuels are of particular interest as an alternative fuel in the transportation sector because their net CO2 footprints can be significantly lower compared to those of traditional fossil fuels. The goal of this dissertation is to study the chemical kinetics of biofuels, which would ultimately allow them to be used more efficiently in the combustion devices of the future. This work is primarily experimental, and it can be divided into three parts: First, the chemical kinetics of butanol, a promising second generation biofuel, were investigated extensively. A variety of kinetic targets such as ignition delay times and species time-histories were measured accurately over a wide range of conditions. These high-accuracy data have been used by research groups around the world in order to validate and improve chemical kinetic models. Second, rate constants for reactions of ethanol and tert-butanol with OH radicals were investigated. These reactions are one of the primary removal pathways of fuels during combustion, and they significantly affect the combustion properties of these fuels. Measurements were performed using isotopic labeling of 18O in the alcohol group in order to eliminate the recycling of OH radicals following H-atom abstraction at [beta]-sites, which commonly perturbs measurements of rate constants for reactions of alcohols with OH radicals. Third, various experimental techniques were developed and improved while performing these measurements. This work presents the first application of isotopic labeling and laser absorption in shock tubes, which shows significant promise for future chemical kinetic studies. Furthermore, the rate constant for cyclohexene decomposition was determined with the highest accuracy to date. These measurements are likely to improve a myriad of comparative rate and chemical thermometry studies that use cyclohexene decomposition as a reference reaction. Finally, a high-temperature laser absorption diagnostic for measuring acetylene concentration was developed. Time-resolved shock tube measurements of this critical combustion intermediate should significantly improve the experimental capabilities for performing chemical kinetic studies.
The objective of this research program is to measure the rates, study the mechanims of pyrolysis of gases at high temperatures and to obtain experimental data on the efficiencies of energy transfer between molecules during collisions. This report summarizes the progress which we have made towad these objectives. This report consists of five papers that have been published or are ready for publication, and two preliminary manuscripts still in the process of revision.
This volume of the Fundamental Kinetic Database Utilizing Shock Tube Measurements includes a summary of the reaction rates measured and published by the Hanson Shock Tube Group in the Mechanical Engineering Department of Stanford University. The cut-off date for inclusion in this volume was January 2009. This work has been supported by many government agencies and private companies including: the U.S. Department of Energy, the Army Research Office, the Office of Naval Research, the Air Force Office of Scientific Research, the National Science Foundation, and the Gas Research Institute.
In order to improve the ignition delay time simulation results, the low temperature oxidation of DIPK was studied as the fuel chemistry effects on the autoignition behavior becomes important in low temperature. Therefore DIPK low temperature oxidation experimental data was obtained from the synchrotron photoionization experiments conducted at the Advanced Light Source (ALS) so that the primary products as well as the dominant oxidation pathways are identified. Furthermore, the aldehydes oxidation, as a result of partial or incomplete combustion and as the primary stable intermediate products in oxidation and pyrolysis of biofuel were studied at low temperature in ALS. A high temperature reaction mechanism was created using the reaction class approach. The reaction mechanism for DIPK was improved using the experimental data along with quantum chemical calculation of activation energies and barriers as well as vibrational modes for the important reactions identified in ALS experiment. The rate constants for important reactions were calculated based on modified Arrhenius equation. DIPK oxidation and pyrolysis were studied at high temperature and pressure using UCF shock tube. The ignition delay times as well as the product (methane) time histories were investigated and used as validation targets for the new model.
Brief summaries are given of the various phases of a research program involving (1) shock tube studies of the kinetics of halogen reactions, and (2) structural chemistry and x-ray crystallographic investigations of aromatic nitroso compounds.
We report results of basic research aimed at improving knowledge of the combustion behavior of diesel and jet-related fuels. The work is intended to develop a reference database of gas-phase chemical kinetics and two-phase spray measurements applicable to engine modeling. Research is being conducted in three Stanford shock tube facilities and focuses on two topics: (1) shock-induced ignition time and species time-history measurements and comparisons with current detailed kinetic models of jet fuels and cyclo-alkanes at both high and low pressures; (2) fundamental studies of fuel spray evaporation rates and ignition times of low-vapor pressure fuels such as JP-8, diesel fuel and normal alkane surrogates in a new aerosol shock tube using state-of-the-art optical diagnostic and imaging techniques.