Investigation of Combustion Diagnosis System Applied for the Development of General Purpose Utility Engines

The chief goal of engineers studying internal combustion engines is to improve energy efficiency in the face of the increasingly severe global warming and energy issues. Hence, there have been numerous studies focusing on the combustion reactions in order to develop clean and reliable combustion that is capable of operating using less fuel. And to improve the comprehension of engine performance and its combustion reactions, development of comprehensive measurement technique for engine performance, in-cylinder visualization technique, and numerical simulations, is essential and strongly demanded. There have hitherto been numerous studies about combustion diagnostics and analysis, including high-efficiency measurement techniques using response surface method the air-fuel mixture distribution and flame propagation measurement with optical visualization techniques, and numerical calculations of combustion reaction with elementary reactions. However, there is room for further work into these technologies during the actual engine development process. Some of the more prominent issues include the need for installing massive equipment, deviation from actual combustion conditions due to the use of visualization windows, and the need for special experiments to evaluate the numerical calculations.

Thus, the goal of this research is to build the efficient and reliable measurements system that can be applied for actual development process with capability of diagnosing engine performance and combustion from a variety of different perspectives. This diagnostic system has been designed a best mix of the advantages of actual engine measurements, combustion diagnostic techniques and numerical simulation. In this system, the automatic measuring with response surface method and optimization algorithm provides a comprehensive overview of engine performance. And the direct measurement of flame propagation and numerical simulation of air-fuel distribution and flame propagation contribute to analyze combustion reaction. And in order to verify this diagnostic system, it has been applied for general purpose utility engines with two different combustion chamber geometries.