The scope of digital colour image processing technique has been
incorporated to capture and extract dynamic information from two
contrasting flame radiation features in an acoustically excited
combustion field. Using broadband digital colour video, and subsequently
extracted broadband colour signals, the dynamic behaviour
of two radiation features can be tracked and profiled simultaneously.
The use of diffusion colour regime has shown to denote
the dynamic behaviour of the soot emission of diffusion methane
flame, the main flame oscillation behaviour. However, this signal
was not able to discriminate the frequency location of the acoustic
excitation in the spectrum profile with sufficient level of clarity. The
premixed colour definition, on the other hand, demonstrated very
good results. The location of the external acoustic excitation frequencies
were accurately matched for all the test cases. Also, observations
were made on the presence of a band of triple peaks
associated with acoustic excitation. This band of secondary peaks
was found to exhibit certain relationship to both the acoustic excitation
frequency and the natural thermal buoyancy-induced frequency
of combustion; that the middle peak coincides with the
acoustic excitation frequency while the fore and aft peaks are separated
by a constant interval of fexcited ± fspectrum,D. The ability to extract
two different results from the same set of broadband flame
image data is advantageous after correlating with different combustion
parameters in which they represent. The processing technique
has demonstrated to be a viable tool for instantaneous
multi-colour based diagnostics of combustion phenomena, and
adds to extend the current development of image-based