Engine Performance and Fire-Safety Characteristics of Water-Containing Diesel Fuels.

Abstract : Recent flammability evaluations conducted at U.S. Army Fuels and Lubricants Research Laboratory (AFLRL) have shown that water-containing diesel fuels are more fire resistant (even at temperatures above the flash point) than the same fuel without the water added. These findings led to this project to evaluate the compatibility of such fuels with a full scale diesel engine. Blends of base diesel fuel plus 2-percent emulsifying agent plus as much as 10-percent water were evaluated in an unmodified LDT-465-1C, a multifuel diesel engine with wide field usage. No significant changes were observed in power output when operating the engine at equal base fuel flow rates. The smoke-reduction effects were inconclusive, but the nonvisible emissions were substantially altered. Oxides of nitrogen emissions were decreased as much as 30 percent but were accompanied by a 250-percent increase in unburned hydrocarbons. The conclusion followed that potential fire-safety benefits and a lack of major detrimental effects in the engine make these water/fuel blends attractive candidates for fire-resistant combat fuels. (Author)