Turbulent flame speeds were measured over a range of pressures to 0.8 MPa using
a jet flow apparatus fired with a synthetic mixture representing a mid-European
natural gas. The equivalence ratio empty set was 0.9. The gas contained
significant proportions of ballast gases and higher hydrocarbons. The method
adopted was the 'flame angle' technique, using schlieren imaging to obtain the
flame vertex angle from the peak density gradient. Image analysis techniques
were developed to reduce interpretation errors and give an unbiased result. The
data show higher flame speeds than those obtained with pure methane at elevated
pressures, using similar methodology, and has an application in numerical
modelling of combustors
