HOW FUELS CAN HELP IMPROVE PERFORMANCE OF FUTURE HIGH-SPEED COMPRESSION-IGNITION ENGINES

1958 ◽  
Author(s):  
Grover C. Wilson
Keyword(s):  
High Speed ◽  
Compression Ignition ◽  
Improve Performance ◽  
Compression Ignition Engines

Autoignition characteristics of diesel spray under different injection pressures and cold start strategy for compression ignition engines

2020 ◽  
pp. 146808742093460
Author(s):  
Ziming Yang ◽  
Fushui Liu ◽  
Yikai Li
Keyword(s):  
High Speed ◽  
Injection Pressure ◽  
Cold Start ◽  
Diesel Spray ◽  
High Speed Photography ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Application Range ◽  
Compression Ignition Engines ◽  
Injection Pressures

Poor cold start performance is one of the main factors restricting the application range of compression ignition engines. Stable flame generation in the cylinder is the prerequisite for the successful start of the engine. In order to explore ways to improve the cold start ability of the compression ignition engine, the ignition characteristics of diesel sprays at different injection pressures were studied in a constant volume combustion chamber. A high-speed photography technique was used to obtain the color images of the initial flames of diesel free sprays. And the yellow flame is introduced as the criterion for a successful flame generation. It was found that under moderate injection pressures, the reactant concentration and energy dissipation rate reached equilibrium. Under this condition, the duration of the blue flame is relatively stable, and it is most conducive to the generation of the yellow flame in the cylinder. The negative temperature coefficient phenomenon is also observed, and the temperature range in which this phenomenon occurs is identical with the change of injection pressure. A cold start strategy for the compression ignition engine is proposed by controlling the compression-end temperature in the cylinder to be higher than the threshold ignition temperature of diesel spray.

The Admiralty Cathode Ray Oscillograph Engine Indicator

1940 ◽  
Vol 143 (1) ◽  
pp. 39-47 ◽  
Author(s):  
F. D. Smith ◽  
E. H. Lakey ◽  
H. Morgan
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Magnetic Circuit ◽  
Narrow Band ◽  
Pressure Gauge ◽  
Compression Ignition ◽  
High Frequency Current ◽  
Compression Ignition Engines ◽  
Pressure Sensitive ◽  
Frequency Current

The Admiralty cathode ray oscillograph indicator was developed for use on compression-ignition engines of medium- and high-speed types. The size of the engine has not necessitated the development of the smallest possible unit. It consists of a pressure-sensitive device based on the magnetophone principle. The pressure to be recorded deflects a steel diaphragm and changes an air gap in a magnetic circuit. The magnet is energized by a high-frequency (20,000 cycles per sec.) alternating current flowing in an encircling coil. The pressure on the diaphragm modulates the high-frequency current, and the modulations are observed on the screen of a cathode ray oscillograph. The advantages of a high-frequency current in this connexion are: (1) all frequencies below about 2,000 cycles per sec. are faithfully reproduced; (2) steady pressures are recorded and calibration is effected with an ordinary pressure gauge; (3) amplifier and circuits have to transmit only a comparatively narrow band of frequencies. A disadvantage is that the upper limit of frequency (2,000 cycles per sec.) is not sufficiently high for the study of very rapid variations. The precautions necessary to ensure accuracy are discussed, and some examples of typical records obtained with the instrument are reproduced.

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