Increase in Maximum Pressures Produced by Preignition in Internal Combustion Engines
Explore the source record for details and available documents.
SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots.
We see with great satisfaction that Bagnulo's studies and experiments on his high-speed, heavy-fuel engines, promise to solve not only the general problem of economical power and hence of thermal efficiency, but also all other special problems, of weight and space, and, what is still more important, range of error.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In compressorless Diesel engines and in explosion engines using fuels with high boiling points it is difficult to effect a good combustion of the fuel mixture. This report presents different methods for calculating the size and uniformity of fuel droplets and mixtures.
The writer discusses the phenomena of expansion and compression which alternately take place in the cylinders of four-stroke engines during the induction process at a high mean piston speed due to the inertia and elasticity of the mixture in the intake pipe. The present paper is intended to demonstrate theoretically the existence of a most favorable pipe length for charging.
Using the method of weighing fuel collected in a receiver during a definite interval of the injection period, rates of discharge were determined, and the effects noted, when various changes were made in a fuel-injection system. The injection system consisted primarily of a by-pass controlled fuel pump and an automatic injection valve. The variables of the system studied were the pump speed, pump-throttle setting, discharge-orifice diameter, injection-valve opening and closing pressures, and injection-tube length and diameter.
An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.
Explore the source record for details and available documents.
These researches present a solution for reducing the fatigue of the Diesel engine by permitting the preservation of its components and, at the same time, raising its specific horsepower to a par with that of carburetor engines, while maintaining for the Diesel engine its perogative of burning heavy fuel under optimum economical conditions. The feeding of Diesel engines by injection pumps actuated by engine compression achieves the required high speeds of injection readily and permits rigorous control of the combustible charge introduced into each cylinder and of the peak pressure in the resultant cycle.
In this report it will be seen that the piston speed - as, moreover, any other speed, such as bearing velocity - must be independent of the quantity dimensions and must be a representative quantity similar to the high speed and the specific weight per horsepower.
The question remains open of the relation between the phenomena of knocking in the engine and the explosion wave. The solution of this problem is the object of this paper. The tests were conducted on an aircraft engine with a pyrex glass window in the cylinder head. Photographs were then taken of various combinations of fuels and conditions.
Internal combustion engine exhaust system sound radiation, discussing pressure wave effects, energy flux and boundary conditions
Past and future progress in the performance of control systems for large, liquid rocket engines typified such as current state-of-the-art, the Shuttle Main Engine (SSME), is discussed. Details of the first decade of efforts, which culminates in the F-1 and J-2 Saturn engines control systems, are traced, noting problem modes and improvements which were implemented to realize the SSME. Future control system designs, to accommodate the requirements of operation of engines for a heavy lift launch vehicle, an orbital transfer vehicle and the aerospace plane, are summarized. Generic design upgrades needed include an expanded range of fault detection, maintenance as-needed instead of as-scheduled, reduced human involvement in engine operations, and increased control of internal engine states. Current NASA technology development programs aimed at meeting the future control system requirements are described.
The application of advanced technology to the design of an integrated secondary power system for future near-sonic long-range transports was investigated. The study showed that the highest payoff is achieved by utilizing secondary power equipment that contributes to minimum cruise drag. This is best accomplished by the use of the dedicated auxiliary power unit concept (inflight APU) as the prime power source for an airplane with a body-mounted engine or by the use of the internal engine generator concept (electrical power extraction from the propulsion engine) for an airplane with a wing-pod-mounted engine.