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Two phases of the U. S. Naval Engineering Experiment Station's current investigation of cavitation erosion in diesel engine coolant systems are described. The first phase is concerned with accelerated cavitation tests as conducted with a magnetostriction apparatus. Various materials and test arrangements were included in the studies. The second phase of the investigation covered the measurement of cylinder liner and block vibration in diesel engines wherein cavitation erosion damage was known to exist. This analysis indicated that the principal source of vibrational energy in the area of cavitation damage was the resonant vibration of the cylinder liners as excited by the impacts of piston slap and cylinder firing pulses.

The events leading to the conception of the soldered aluminum-fin brass-tube radiator are reviewed. Considerations affecting the choice of radiator design and the materials to be used for its components are discussed. The experimental techniques used to produce a number of these radiators for testing purposes are set forth and some of the results of these tests are described. This paper concludes that the soldered aluminum-fin brass-tube radiator can be made to perform satisfactorily and provide adequate service. It is the author's opinion, however, that if there were no differential in the cost of using copper and aluminum, copper would be preferred in most respects, except for weight. Information is currently being accumulated to determine whether this type of construction can be made economically in mass production.

Upon reviewing the paper, “Restrictive Specifications Will Increase Jet Fuel Costs,” it should be borne in mind that the material was prepared from data on a given crude with the principal objective of showing a generalized picture of how various fuel properties influence fuel availability. Consequently, too much weight should not be placed upon the absolute values shown. Furthermore, in conducting the analysis, the U.S. tax limits on gasolines were considered as limiting factors. Petroleum stocks having 10% distillation temperatures over 347ºF. and 95% distillation temperatures over 464ºF. are not subject to the Federal gasoline tax. If it were assumed permissible to deviate from either the 10% distillation limit of 347ºF. minimum or the 95% distillation limit of 464ºF. minimum, there would be noticeable differences in product availability as compared to those shown.

Mathematical relationships have been developed whereby excellent correlations are obtained between the road antiknock performance of conventional volatility gasolines and their Research and Motor octane numbers. Correlation equations for current and experimental high compression ratio engines at a given speed are about the same as in older cars of about 7:1 C.R. Although the road antiknock performance of fuels varies greatly from car to car, good correlations with laboratory octane ratings are obtained in cars causing extremes in fuel octane performance as well as in the average car. Fuel depreciation (Research O.N.-Road O.N.) is shown to be a poor measure of the relative effects of Research and Motor O.N. on road antiknock performance in many instances. Neither can fuel depreciation be used as a good measure of relative engine severity. A new definition of engine severity is proposed.

The paper opens with a review of the performance development of Rolls-Royce Propeller Turbine Engines up to and including the Tyne Engine (RB.109), and shows the improvement in both power output and specific fuel consumption and the means by which the improvements have been achieved. It then examines the experience gained by the operation of the Dart engine in the Viscount aircraft and makes certain proposals for modification to the methods for testing engines suggested by this experience. It describes the bench and flight testing which was carried out to define the problems of engine and propeller control with the propeller turbine engine and the current solutions to those problems for the different engine types. This section includes a description of the various safety devices which it has been necessary to include in the control system to prevent prohibitive drag or excessive engine speed following engine or control system failures.

Potential sources of hazard from operation of gas turbine powered aircraft are examined. Comparison is made to the current operation of piston engines. It is concluded that gas turbines are potentially more reliable than piston engines, and they therefore are potentially safer, providing that sufficient care is used to combine all currently available knowledge and experience into the detail design of new aircraft-engine combinations. Specific recommendations are made for further coordination of engine designers and operators for better future power plants, such as better containment provisions, free-turbine arrangements for turbo-props and less surge-sensitive compressors.