Abstract
The oil engine is the most efficient self-contained prime mover so far developed, and endeavors are now being made to adapt it to the high-speed service required in automotive vehicles and aircraft. The author discusses the difficulties encountered in obtaining uniformly controlled and efficient combustion at high speeds, and enumerates the factors upon which the solution of these problems depend. He also considers the advantages of light-weight, high-speed, high-capacity oil engines in aircraft, namely, high cycle efficiency, ability to burn heavy fuels efficiently, and general mechanical simplicity and better adaptability to the two-stroke cycle. He then establishes formulas for the evaluation of aircraft-engine performance, using them in comparing the performance of 85 different carburetor aircraft engines, both air- and water-cooled, and 101 different oil engines. He concludes by giving brief particulars of researches being conducted by the N.A.C.A. to determine the laws governing the hydraulics of fuel-injection systems, and the formation and distribution of oil sprays, as well as their ignition and combustion in spray combustion chambers and in engines fitted with various pistons and cylinder heads.
