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The Diesel-type three-hole Spray B (injector 211201) of the Engine Combustion Network (ECN) was used in a single-cylinder light-duty optically-accessible Diesel engine. A simple optical method was developed to quasi-simultaneously image both liquid and gas phase of the fuel spray as well as combustion at kHz rates by retro-reflection of pulsed LED light from the fire deck. From the images, liquid penetration length, fuel vapor penetration, spray dispersion angle, ignition delay, flame luminosity, and ignition location were determined. Wide-field imaging allowed for studying the nozzle hole-to-hole variation. In addition to a variation of ambient temperature and density to achieve the standard ECN condition, a variation of fuel rail pressure and swirl ratio was also investigated, under both non-reacting and reacting conditions. The results show physically reasonable variations with different operating conditions.

Knocking combustion is associated with extremely high in-cylinder pressure rise rates, strong pressure oscillations, destructive engine vibration, as well as audible noise. It not only exists in spark-ignition (SI) engines but also in compression-ignition (CI) engines, for both conventional Diesel and more premixed modes of combustion. Recent work showed that during Diesel knock the flame’s motion synchronizes with the in-cylinder pressure ringing. To improve the optical method and investigate knock in CI engines further, we imaged the flame luminosity with n-dodecane as a Diesel surrogate in an optically accessible engine during knock at very high frame rates (60 kHz). First, the knocking time interval was determined based on the temporal variation of the mean image intensity. Within this time interval, the instantaneous flow fields were calculated by “optical flow” based on cross-correlation.

This paper describes a new long life, heavy duty, air-to-air charge air cooler (CAC) which has particular application in heavy duty trucks, buses, off-highway vehicles and construction equipment. In this paper, it is proven through structural modeling and fatigue analysis on actual service histories that plastic flow and the resulting cumulative damage make it impossible for a typical brazed charge air cooler to meet minimum reliability requirements in at least some applications. Thermal expansion of the charge air cooler core, internal pressure, and external shock and vibration all contribute to a complex stress/strain response behavior in the area of the tube-to-header joint. Testing showed that the use of resilient tube-to-header joints, utilizing grommeted seals between the tubes and headers, eliminates the high stresses in this area and provides a theoretically infinite life.