Effect of a Metal Deactivator Fuel Additive on Fuel Deposition in Fuel Atomizers at High Temperature
Abstract
Fuel additives that are metal deactivators have been shown to improve the thermal stability breakpoint temperature of aviation fuels as determined in the Jet Fuel Thermal Oxidation Tester (JFTOT). These additives therefore, offer the opportunity to upgrade fuels of marginal thermal stability. However, concern has been expressed over whether this upgrade would be realized in actual aircraft hardware. To address this concern, an experimental project has been conducted with fuel atomizers from the T700 engine to determine the effect of the additive DMD-2, a metal deactivator, on high-temperature fuel deposition. The tests were conducted with JP-5 fuel supplied by the Naval Air Warfare Center Aircraft Division, Trenton NAWCADTRN). For some of the tests, the base fuel was contaminated with copper to a concentration between 400 and 500 ppb. In the uncontaminated fuel, the metal deactivator (MDA) additive was tested at a concentration of 1 ppm; in the contaminated fuel, MDA concentrations of 1 ppm and 5.7 ppm were tested. With uncontaminated fuel, the results showed that initially the additive significantly reduced the deposition rate, but then, after an induction period, the position rate sharply increased. With the copper- contaminated fuel, at 1 ppm, the ad e showed a small effect, but did not completely passivate the copper. At 5.7 ppm, there was no significant deposition during the test, indicating the copper was passivated. It is concluded that the metal deactivators inhibit deposition for a period of time until the surface becomes coated with carbon deposition, and then they no longer serve any function. These results are consistent with some single-tube heat exchanger experiments reported in the literature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1992
- Accession Number
- ADA260915
Entities
People
- Clifford A. Moses
Organizations
- Southwest Research Institute