Thermal Contact Conductance (TCC) between an exhaust valve and its seat is one of the important parameters to be estimated in an internal combustion engine. An experimental study presented here to acquire temperature in some interior points to be used as inputs to an inverse analysis. An actual exhaust valve and its seat are utilized in a designed and constructed setup. Conjugate Gradient Metho...

By modulating engine valves to reinduct hot exhaust gas together with air and fuel, a clean and efficient form of autoignition can be created. Control of this combustion process, known as homogeneous charge compression ignition (HCCI), requires not only precise valve control but also a combustion control strategy that accounts for the cycle-to-cycle coupling through the exhaust. This paper outl...

thermal contact conductance (tcc) between an exhaust valve and its seat is one of the important parameters to be estimated in an internal combustion engine. an experimental study presented here to acquire temperature in some interior points to be used as inputs to an inverse analysis. an actual exhaust valve and its seat are utilized in a designed and constructed setup. conjugate gradient metho...

Homogeneous charge compression ignition (HCCI) seems to be the most promising solution for gasoline engines in the light of future emissions regulations. This novel combustion technique allows for significant reduction of fuel consumption and engine-out NOX emissions at low and medium engine load/speed conditions. High heat release rate enables realization of the Otto cycle close to ideal, incr...

In this paper, the influence of the gas exchange process on the diesel engine thermal overload is provided. Main components involved in the gas exchange process are discussed. The ambient conditions, the turbocharger performance, and the valve timing that affect the gas exchange process have been investigated. Experiments were conducted to simulate ambient conditions at different geographical l...

In order to understand how unburned hydrocarbons emerge from SI engines and, in particular, how nonfuel hydrocarbons are formed and oxidized, a new gas sampling technique has been developed. A sampling unit, based on a combination of techniques used in the Fast Flame Ionization Detector (FFID) and wall-mounted sampling valves, was designed and built to capture a sample of exhaust gas during a s...

The experimental study was conducted to investigate the effects of different opening ranges of waste gate of a turbocharged medium displacement spark ignition engine on improving work parameters such as exhaust emission, torque characteristics and fuel consumption. The object of the experimental tests was an engine with modified intake and exhaust manifolds. The intake and exhaust manifold modi...

A vibroacoustic signal of an internal combustion engine contains several diagnostic information, which are for the most part not utilised since they require complex processing methods in order to separate useful data and to eliminate disturbances. The way of analysis of such complex signal depends on the diagnostic aim. It is a rich source of information not only concerning the combustion proce...

This is especially true for exhaust valves, due to the high temperature environment to which the valve is exposed. In a paper presented at the GMRC 2007 Gas Machinery Conference[1], it has been shown that statistical techniques and histograms of valve vibration data can be used to identify valve faults that can lead to valve failures. This paper will discuss refinements made to the statistical ...

In this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in XU7/L3 engine. In this study, considering the strength and accuracy of simulation GT-POWER software in researches on the internal combustion engine...