NASA Selects Reaction Design to Develop Fuel Models for Alternative Jet Fuels
27 June 2007
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| Sample CHEMKIN output. Click to enlarge. |
The National Aeronautics and Space Administration (NASA) has selected Reaction Design, a leader in combustion simulation technology, to develop fuel models for simulating the operation of jet engines with alternative fuels.
The two-year project will be led by Reaction Design with experimental support from researchers at the University of Southern California. The project will develop detailed chemical kinetics models and validate them with experimental data to allow prediction of important parameters related to ignition, extinction, and pollutant formation for Fischer-Tropsch fuels and biofuels for both commercial and military jet engines.
The project’s key objective is to develop a comprehensive set of fundamental data on the combustion of alternative jet fuels, using a surrogate fuel approach. The results will provide guidance to the planning and design of optimal fuel-production processes.
Both the understanding of detailed chemistry and the processing power of computers have greatly increased in the last decade, enabling accurate simulation of combustion for enhanced, clean-technology design. Petroleum fuels such as kerosene contain hundreds of different hydrocarbon species that all contribute in specific ways towards ignition, flame propagation and pollutant formation.
The traditional technique of simulating these fuels using empirically-derived chemistry parameters does not provide the accurate emissions predictions nor the necessary detail required for use in design and optimization, according to the company. Thus, the development of accurate surrogate fuel models for use in chemical kinetic simulations is a critical step toward enabling computer-aided engine and fuel design for petroleum and alternative fuels alike.
Reaction Design is the exclusive developer and distributor of CHEMKIN, widely used software for modeling gas-phase and surface chemistry. Reaction Design also offers the KINetics software package, which brings detailed kinetics modeling to other engineering applications, such as Computational Fluid Dynamics (CFD) programs.
Reaction Design also leads the Model Fuels Consortium (MFC). (Earlier post.)
On these web pages a month or more ago, I predicted that for air transport applications, mankind would eventually be creating specific synthetic fuels.
As Jet engines are external combustion engines it is possible to define the "ideal" molecular weight of a fuel and purposely create a fuel composed of only those monomers. That is a way of optimizing efficiency, reducing emitted pollutants to the absolute lowest amount possible, and increasing the efficiency to the Nth degree.
Air transport does not lend itself to non-hydrocarbon fuel sources. You can't just run out an electric cord and fuel cells and batteries are just too heavy. Unlike Ground transport that is amenable to electrification and all kinds of fuel substitution.
When the bottom falls out of petroleum demand, as it will within the next decade or two, synthetic fuels will be the way forward. All air transport consumes only a few percent of today's petroleum demand, and that few per cent will always be available, even if custom manufactured.
There appears to be only one theoretically feasible fuel source other than hydrocarbon chemical fuels and that is a 2HE3 anuetronic fusion reaction that produces a direct conversion to electricity without requiring shielding. If feasible for air transport applications, that may be at least 25 years off but probably much longer.
For certain technologies such as scram jets, it may be necessary to perfect monomer hydrocarbon fuels,merely to keep the flame front burning. Running a scram jet engine has been analogized to be like trying to keep a candle burning in the midst of a hurricane.
A primitive version of this was done in preparing the "JP9" special super-refined fuel used on the SR-71 blackbird spy plane. In that case all they did was to prepare a mixture of ordinary fuel such that there was a reduced but still not singular number of similar weighted hydrocarbon molecules.
Posted by: Stan Peterson | 27 June 2007 at 10:48 AM
Jet engines are INTERNAL combustion Brayton cycle engines. If you want to be believeable get your facts straight.
Posted by: tom deplume | 27 June 2007 at 03:42 PM