SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 13 - JULY 5, 2006

28 PROPELLANTS AND FUELS
Includes rocket propellants, igniters, and oxidizers; their storage and handling procedures; and aircraft fuels.

For nuclear fuels see 73 Nuclear Physics.

For related information see also 07 Aircraft Propulsion and Power; 20 Spacecraft Propulsion and Power; and 44 Energy Production and Conversion.

20060016441 NASA Marshall Space Flight Center, Huntsville, AL, USA

Prediction of Composite Pressure Vessel Failure Location using Fiber Bragg Grating Sensors

Kreger, Steven T.; Taylor, F. Tad; Ortyl, Nicholas E.; Grant, Joseph; [2006]; 1 pp.; In English; SPIE's 13th Annual International Symposium on Smart Structures and Materials, 16 Feb - 2 Mar. 2006, San Diego, CA, USA; Copyright; Avail.: Other Sources; Abstract Only

Ten composite pressure vessels were instrumented with fiber Bragg grating sensors in order to assess the strain levels of the vessel under various loading conditions. This paper and presentation will discuss the testing methodology, the test results, compare the testing results to the analytical model, and present a possible methodology for predicting the failure location and strain level of composite pressure vessels. Author

Bragg Gratings; Failure; Mathematical Models; Position (Location); Pressure Vessels; Composite Structures; Sensors

20060018921 Reaction Engineering International, Salt Lake City, UT USA

Reduced Chemical Kinetic Mechanisms for Hydrocarbon Fuels

Montgomery, Christopher J; Cremer, Marc A; Chen, Jyh-Yuan; Westbrook, Charles K; Maurice, Lourdes Q; Jan 2006; 36 pp.; In English Contract(s)/Grant(s): F33615-98-C-2831 Report No.(s): AD-A445989; No Copyright; Avail.: CASI: A03, Hardcopy

Several reduced chemical kinetic mechanisms for combustion of ethylene and n-heptane have been generated using CARM (Computer Aided Reduction Method), a computer program that automates the mechanism-reduction process. The method uses a set of input test problems to rank species by the error introduced by assuming they are in quasi-steady state. The reduced mechanisms have been compared to detailed chemistry calculations in simple homogeneous reactors and experiments. Reduced mechanisms for combustion of ethylene having as few as 10 species were found to give reasonable agreement with detailed chemistry over a range of stoichiometries. Much better agreement with detailed chemistry was found for ethylene ignition delay when the reduced mechanism was tuned through selection of input test problems. The performance of reduced mechanisms derived from a large detailed mechanism for n-heptane was compared to results from reduced mechanisms derived from a smaller semi-empirical mechanism. The semi-empirical mechanism was clearly advantageous as a starting point for eduction for ignition delay, but the differences were not as notable for perfectly-stirred-reactor (PSR) calculations. Reduced mechanisms with as few as 12 species gave excellent results for n-heptane/air PSR calculations but 16-25 or more species are needed to simulate n-heptane ignition delay. DTIC

Fuels; Hydrocarbon Fuels; Hydrocarbons; Reaction Kinetics

Source: NASA