Nissan Motor, in collaboration with Stanford University and Physical Science Inc. (PSI), has developed technology to measure in-cylinder gas temperatures and a way to analyze the combustion in real-time during engine operation.
The new technology should further the understanding of combustion, and contribute to developing future generation engines with improved fuel efficiency and reduced emissions.
This system uses a semiconductor laser to calculate the temperature from measurements of gas concentration in the combustion chamber. This technology can be applied via a very small temperature probe that can be installed in a spark plug, enabling non-intrusive, real-time measurements.
Previous methods to measure the combustion gas required modifications to the engine. It was difficult to acquire useful data from methods such as attaching sensors inside the cylinder wall or estimating the temperature from camera images of the flame obtained in a specially modified optical-access engine.
The collaboration began in November 2002 between Nissan and Stanford. PSI subsequently joined the project to assist in the development of the new technology.
Nissan’s specific role was in the optical design of the temperature probe and overall project management, while Stanford University researchers were in charge of creating the basic concepts and methodology. PSI took charge of laser device development.
I am extremely pleased with our success at linking cutting-edge science with advanced engineering technology through this collaboration with Nissan. I believe that this technology will contribute to the development of future environmentally friendly engines and to the overall progress of measurement technologies.—Professor Ronald K. Hanson, Mechanical Engineering Dept. of Stanford University
One of the major activities of the Hanson Research Group at Stanford is the research of laser diagnostics for sensing and control. The group has and continues to develop a wide range of diagnostics that employ tunable diode laser absorption spectroscopy for sensing temperature, pressure, and a variety of chemical species. These diagnostics can be used to monitor and control combustion emissions, plasma semiconductor processing flowfields, fuel leaks, and bioreactor exhaust.
Detailed results of this study will be published by the Institute of Physics and by the Optical Society of America in 2006, and also by the Society of Automotive Engineers International.
Stanford Ronald K. Hanson Research Group