This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Measurement of Exhaust Gas Temperatures in a High Performance Two-Stroke Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published November 16, 1998 by SAE International in United States
Annotation ability available
The performance characteristics of two-stroke engines are highly dependent upon the gas dynamic wave action in the exhaust system. In a tuned high performance exhaust system, negative suction pulses aid induction of charge into the cylinder, while positive waves aid its retention. The timing of these waves is closely related to the acoustic velocity, and is therefore dependent on the exhaust gas temperature (EGT).
In advanced engine management systems, the control strategy may be tailored to influence the EGT, and to maximize the beneficial influence of the gas dynamics in the exhaust. Therefore, accurate measurement of EGT is required for development purposes, and real-time feedback could potentially be used as an input to the management system. However, accurate measurement of exhaust gas temperature is fraught with difficulties due to a number of sources of error. Steady state errors can arise due to conduction and radiation of heat from the thermocouple junction, while in transient operation, additional errors arise due to the slow responses of the robust thermocouples which are required to survive the harsh environment.
In this study, the influence of the thermocouple geometry on the steady state errors has been estimated, and a technique has been developed to reconstruct mathematically the instantaneous temperature from the output of two dissimilar thermocouples. Results are presented to demonstrate that the reconstructed temperature correlates well with measurements from a fast-response thermocouple.
CitationKee, R., O'Reilly, P., Fleck, R., and McEntee, P., "Measurement of Exhaust Gas Temperatures in a High Performance Two-Stroke Engine," SAE Technical Paper 983072, 1998, https://doi.org/10.4271/983072.
- Fleck, R. “Expanding the Torque Curve of a Two-Stroke Motorcycle Race Engine by Exhaust Water Injection” SAE paper No. 931506
- Blair G.P. “Design and Simulation of Two-Stroke Engines,” SAE Publication No. R-161 1-56091-685-0 1996
- Hata N Iio T “Improvement of two stroke engine performance with the Yamaha Power Valve System (YPVS)” SAE paper No. 810922
- Caton J.A. “Comparisons of Thermocouple, Time-Averaged and Mass-Averaged Exhaust Gas Temperatures for a Spark-Ignited Engine,” SAE Paper No. 820050
- Bauer W. Tam C. Heywood J.B. “Fast Gas Temperature Measurement by Velocity of Sound for IC Engine Applications,” SAE Paper No. 972826
- Bradley D. Mathews K.J. “Measurement of High Gas Temperatures with Fine Wire Thermocouples,” J. Mechanical engineering Science 10 299 305 1968
- Forney L.J. Fralick G.C. “Two wire thermocouple: Frequency response in constant flow,” Rev. Sci. Instrum. 65 10 October 1994
- Ballantyne A. Moss J.B. “Fine Wire Thermocouple Measurements of Fluctuating Temperatures,” Combustion Science and Technology 17 63 72 1977
- Cambray P. Combustion Science and Technology 45 221 224 1985
- Scadron M.D. Warshawsky I. “Experimental Determination of Time Constants and Nusselt Numbers for Bare-Wire Thermocouples in High Velocity Air Streams and Analytic Approximation of Conduction and Radiation Errors,” NACA Technical Note 2599 81 85
- Kee R.J. et al. “Validation of a Two-Stroke Engine Simulation by a Transient Test Method,” Small Engine Technology Conference Yokohama 1997 JSAE Paper No. 9734683, SAE Paper No. 972135
- Tagawa M. Ohta Y. “Two-Thermocouple Probe for Fluctuating Temperature Measurement in Combustion - Rational Estimation of Mean and Fluctuating Time Constants,” Combustion and Flame 109 549 560 The Combustion Institute 1997