Page:Performance of a high-speed compression-ignition engine using multiple orifice fuel injection nozzles.djvu/5

N.A.C.A. Technical Note No. 344 with different combustion chambers. Taylor (Reference 3) reports excellent performance in his work with multiple orifice nozzles at the Royal Aircraft Establishment. The National Advisory Committee for Aeronautics has published a report by Gardiner (Reference 4) on an attempt to make the compression space conform somewhat to the shape of the spray.

This present report includes data from tests made while attacking the problem of distribution in two different ways. The first was the commonly used method of conducting a series of engine performance tests and systematically varying the number, direction, and size of the orifices until the test results indicated an optimum value in any series of changes. The second method consisted in mathematically proportioning the discharge of each orifice to the volume of air to be served by the spray from this orifice. As a matter of convenience and to have a basis of comparison., results from the first method were used as a starting point for the second. Neither method alone is entirely satisfactory, as yet, for a basis of nozzle design and the work along this line is by no means complete. However, the results attained are being published at this time to show the possibilities of improving engine performance through the design of fuel injection valve nozzles.