SOLUTION of the problem of igniting and burning the fuel in the high-speed Diesel engine profoundly affects its development, according to the authors.
This paper describes the photo-electric set-up selected to indicate the behavior of the fuel in the combustion-chamber because of its high speed, its intensity, its zero time lag, and its freedom from inertia effects.
A magnetic-type oscillograph for recording the impulses, a cantilever-spring indicator for picking up the pressure impulse, and an amplifier between the photo-cell and the oscillograph, comprise the principal parts of this instrumentation, as applied to a single-cylinder test engine.
Results of tests with a three-beam vibrator-type oscillograph are given with oscillograms for different fuels, loads, and injection angles.
Other tests are described using a cathode-ray oscillograph and a high-speed camera.
This high-speed indicating system, recording three simultaneous impulses, furnishes the means for studying a variety of combustion problems in both Otto- and Diesel-cycle engines.
Twenty-four varied Diesel fuels were studied in both the present test engine and in a commercial high-speed unit in the summer of 1936.