Page:Performance of a high-speed compression-ignition engine using multiple orifice fuel injection nozzles.djvu/3

N.A.C.A. Technical Note No. 344 two 0.018-inch orifices as a basis.

A table and curves are presented showing the performance of the engine with different nozzles. Indicator cards and spray photographs are included. The test results are discussed, and some probable reasons given for the variation in performance with different nozzles on a basis of spray distribution. Conclusions are drawn as to the possible application of these results to the design of fuel injection valve nozzles for use with a combustion chamber having a low rate of air flow.

The information available on the performance characteristics of high-speed, compression-ignition engines has usually, been published as results of tests of particular engines, and these results have been judged entirely on a basis of brake horsepower and specific fuel consumption. Much more detailed information is necessary for a foundation upon which to base further development so that the inherent advantages of this type of engine may be generally used in aerial transportation.

The fundamental problem of the compression-ignition engine is the bringing of all the fuel into contact with sufficient air for its combustion. The particular problem of the lightweight, airless injection engine at high speeds is to obtain, in the short time available, a complete mixing and burning of a fuel charge large enough to unite with all the inducted air.