Temperature Measurements of Combustion Gas in a Spark Ignition Engine By Infrared Monochromatic Pyrometry 891258
Instantaneous temperature of in-cylinder gas provides a lot of
useful and local information for analyzing the combustion process
in an internal combustion engine. From the standpoint of
applicability to a practical engine, the infrared monochromatic
radiation pyrometry required only a single optical window is
considered to be more suitable comparing with the conventional
infrared absorption-emission pyrometry with two optical windows.
Then, the former pyrometer is used to measure the mean gas
temperatures averaged on an optical path (or cylinder diameter) of
a spark ignition engine connected to a prechamber with a torch
nozzle of various area sizes.
These measured temperature-crankangle diagrams not only clarify
the influences of torch jet flow on the combustion processes, but
also correspond well to the heat release rates calculated from the
pressure diagrams. Furthermore, they are in reasonable agreement
with the ensemble-averaged brightness on the image-processed
pictures of flame propagation.
In conclusion, the infrared monochromatic pyrometry will be
available to measure the gas temperatures in the combustion chamber
of a practical engine with only an optical window.