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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

Effect of Oxygen Concentration on Autogenous Ignition Temperature and Pneumatic Impact Ignitability of Nonmetallic Materials

Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition temperature testing and pneumatic impact testing were used to better understand the effects of oxygen concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21, 34, 45, and 100 %. The following materials were tested: PTFE Teflon(Registered Trademark), Buna-N, Silicone, Zytel(Registered Trademark) 42, Viton(registered Trademark) A, and Vespel(Registered Trademark) SP-21.

Smith, Sarah↗
NASA NTRS1971

Ignition Temperatures of Metals in Oxygen Atmospheres

The ignition temperature of ten common non-toxic metals has been determined experimentally in an oxygen environment. In this investigation a induction furnace facility that emphasized the preignition surface.oxidation effects upon the ignition temperature was used. The bulk ignition temperatures of barium, bismuth, calcium, iron, lead, magnesium, molybdenum, strontium, tin, and zinc were found and compared to the previous results of Grosse and Conway. The differences in the results are attributed to how the heating cycle is carried out and how the cycle affects the surface oxide coat.

Laurendeau, N. M.↗
NASA NTRS1974

Spontaneous ignition temperature limits of jet A fuel in research-combustor segment

The effects of inlet-air pressure and reference velocity on the spontaneous-ignition temperature limits of Jet A fuel were determined in a combustor segment with a primary-zone length of 0.076 m (3 in.). At a constant reference velocity of 21.4 m/sec (170 ft/sec), increasing the inlet-air pressure from 21 to 207 N/sq cm decreased the spontaneous-ignition temperature limit from approximately 700 to 555 K. At a constant inlet-air pressure of 41 N/sq cm, increasing the reference velocity from 12.2 to 30.5 m/sec increased the spontaneous-ignition temperature limit from approximately 575 to 800 K. Results are compared with other data in the literature.

Ingebo, R. D.↗
NASA NTRS1986

Comparative results of autogenous ignition temperature measurements by ASTM G 72 and pressurized scanning calorimetry in gaseous oxygen

The autogenous ignition temperature of four materials was determined by ASTM (G 72) and pressurized differential scanning calorimetry at 0.68-, 3.4-, and 6.8-MPa oxygen pressure. All four materials were found to ignite at lower temperatures in the ASTM method. The four materials evaluated in this program were Neoprene, Vespel SP-21, Fluorel E-2160, and nylon 6/6.

Bryan, C. J.↗
NASA NTRS1985

Near-infrared two-color pyrometer for determining ignition temperatures of metals and metal alloys

A two-color pyrometer has been designed, constructed, and used to measure the ignition temperatures of metals and metal alloys. Cylindrical metal and metal alloy specimens were ignited by a focused cw CO2 laser beam in a cool, static, pure oxygen environment. The pyrometer operates in the near-infrared at two narrow spectral regions, with a nominal bandwidth of 10 nm centered at 0.9051 and 1.06 micron, and has a temperature range from 1000 to 4000 K. In the present design the temperature of a spot, about 0.5 mm in diameter, can be recorded with a maximum time resolution of 25 microseconds and with an accuracy of a few percent. Results of CO2 laser ignition of cylindrical specimens of 6061 aluminum alloy and 302 SS in a pure oxygen environment were obtained from the two-color pyrometer and were compared with those obtained from a thermocouple placed inside the specimen near the laser-irradiated surface.

Nguyen, K.↗
NASA NTRS2020

Determination of Autogenous Ignition Temperature for Isopropyl Alcohol and Ethanol

As part of a recent liquid rocket engine shutdown investigation, a commercial partner requested that NASA provide the autogenous ignition (or autoignition) temperature (AIT) of isopropyl alcohol (IPA). NASA provided the available data, but the data were somewhat scattered, likely due to test configuration and test technique differences. NASA Engineering and Safety Center (NESC) support was requested to experimentally determine the AIT of IPA and ethanol, both of which are extensively applied to propulsion systems. This report contains the outcome of the NESC assessment.

Autoignition Temperature; Isopropyl Alcohol; Comme↗
NASA NTRS2011

Innovative Comparison of Transient Ignition Temperature at the Booster Interface, New Stainless Steel Pyrovalve Primer Chamber Assembly "V" (PCA) Design Versus the Current Aluminum "Y" PCA Design

An assessment of four spacecraft pyrovalve anomalies that occurred during ground testing was conducted by the NASA Engineering & Safety Center (NESC) in 2008. In all four cases, a common aluminum (Al) primer chamber assembly (PCA) was used with dual NASA Standard Initiators (NSIs) and the nearly simultaneous (separated by less than 80 microseconds) firing of both initiators failed to ignite the booster charge. The results of the assessment and associated test program were reported in AIAA Paper AIAA-2008-4798, NESC Independent Assessment of Pyrovalve Ground Test Anomalies. As a result of the four Al PCA anomalies, and the test results and findings of the NESC assessment, the Mars Science Laboratory (MSL) project team decided to make changes to the PCA. The material for the PCA body was changed from aluminum (Al) to stainless steel (SS) to avoid melting, distortion, and potential leakage of the NSI flow passages when the device functioned. The flow passages, which were interconnected in a Y-shaped configuration (Y-PCA) in the original design, were changed to a V-shaped configuration (V-PCA). The V-shape was used to more efficiently transfer energy from the NSIs to the booster. Development and qualification testing of the new design clearly demonstrated faster booster ignition times compared to the legacy AL Y-PCA design. However, the final NESC assessment report recommended that the SS V-PCA be experimentally characterized and quantitatively compared to the Al Y-PCA design. This data was deemed important for properly evaluating the design options for future NASA projects. This test program has successfully quantified the improvement of the SS V-PCA over the Al Y-PCA. A phase B of the project was also conducted and evaluated the effect of firing command skew and enlargement of flame channels to further assist spacecraft applications.

Saulsberry, Regor L.↗
NASA NTRS1985

Thermonuclear reactions in cool accreting neutron stars and burst phenomena

The ignition of accreting materials on neutron stars is explored using strongly coupled plasma analytical techniques. The calculations cover the ignition temperature and density at the bottom of the accreted envelope of a neutron star. Emphasis is placed on low-temperature ignitions which take place at high densities. The investigation is extended to the accretion of material from a white dwarf in the form of pure He, C + O, or O + Ne + Mg. It is shown that electrons are strongly degenerate in low-temperature flashes, where the ignition is more dependent on density than on temperature. Precursor flashes 0.4-0.7 the intensity of the main burst will appear before the main bursts. The intensity relationship indicates that the appropriate model for an X-ray burst from a neutron star accreting from a white dwarf is a He shell flash in the presence of a hydrogen-rich atmosphere. The flash will have a maximum energy of 2 x 10 to the 43 ergs and could last as long as 40,000 sec.

Miyaji, S.↗