Three-dimensional imaging of fuel tracer planar laser-induced fluorescence in a homogeneous charge compression ignition (HCCI) engine is presented. A high-speed multiple Nd:YAG laser and detection system, in combination with a scanning mirror, are used to collect eight images, with an equidistant separation of 0.5 mm. Three-dimensional isoconcentration surfaces calculated from the data are visu...

In this article, a stochastic gradient based online learning algorithm for Extreme Learning Machines (ELM) is developed (SG-ELM). A stability criterion based on Lyapunov approach is used to prove both asymptotic stability of estimation error and stability in the estimated parameters suitable for identification of nonlinear dynamic systems. The developed algorithm not only guarantees stability, ...

Cyclic variability (CV) in lean HCCI combustion at the limits of operation is a known phenomenon, and this work aims at investigating the dominant effects for the cycle evolution at these conditions in a multi-cylinder engine. Experiments are performed in a four-cylinder engine at the operating limits at late phasing of lean HCCI operation with negative valve overlap (nvo). A combustion analysi...

Youth suicide is a serious, yet preventable, public health concern for ethnic minorities and rural communities. This paper describes the youth leadership model utilized by Hawai‘i’s Caring Communities Initiative (HCCI) and provides reflections on the important factors for success in implementing a youth and community advocacy project for youth suicide prevention. HCCI partnered with six youth a...

Abstract In the current study, electrolytic deposition using two different electrodes, copper (Cu) and nickel (Ni) was investigated with aim of protecting worn surface during mechanical sectioning polishing, for a posterior examination sub-surface microstructure. The efficacies coatings were visually assessed based on its adhesivity ability to protect wear tracks an as-cast 26% Cr high chromium...

Three-dimensional time-dependent CFD simulations of autoignition and emissions are reported for an idealized engine configuration under HCCI-like operating conditions. The emphasis is on NOx emissions. Detailed NOx chemistry is integrated with skeletal autoignition mechanisms for n-heptane and iso-octane fuels. A storage/retrieval scheme is used to accelerate the computation of chemical source ...

The alternative HCCI combustion mode presents a possible means for decreasing the pollution with respect to the conventional gasoline or diesel engines, while maintaining the efficiency of a diesel engine or even increasing it. This paper investigates the possibility of using gasoline in an HCCI engine and analyses the auto-ignition of gasoline in such an engine. The compression ratio that has ...

In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured. The inlet temperature was changed from 25 to 70 °C and the equiva...