Diesel Fuels - Significance of Ignition Characteristics 360119
DATA are presented showing the results of extensive tests of Diesel fuels of widely different ignition characteristics in laboratory and service engines. The tests in laboratory engines are particularly significant in demonstrating the influence of controlled differences in operating conditions upon the relative ease of ignition of fuels.
The tests in service engines show that each engine has distinct minimum requirements for fuel-ignition quality; that the minimum required is different under different operating conditions; and that no essential difference in the performance of fuels can be noted as long as the minimum ignition quality is exceeded. For all practical purposes, therefore, no correlation appears possible between the laboratory rating of Diesel fuel ignition characteristics and service behavior.
The conclusion is advanced that, since fuels equal or superior to the minimum for any engine are required to secure freedom from the difficulties attending incomplete combustion and since no essential differences can be noted between fuels exceeding the minimum quality, the development of laboratory tests for evaluating the ignition characteristics of fuels is of primary utility at the present time in aiding the engine manufacturer to secure experimental fuels of known ignition quality to further the development of engine design.