The study of fine particulate matter from gasoline direct-injection engines, and in particular the size distribution and number of particles emitted, has been a significant focus of the Group's work in recent years. Measuring the number of particles is far more complicated than measuring the mass, since particles may be involved in mechanisms such as deposition, mutation, particle-to-gas conversion, etc. during the exhaust process, which may change the measured total number.
Various number-based particulate measurement instruments are commercially available as research tools. However, valid measurements require in-depth knowledge of numerous experimental variables with the central objective being that the results should be representative of real exhaust particulate emission. It is also desirable to resolve the composition and the morphology of the particles emitted, which could enable researchers to model the formation of particulate matter and to understand the impact on health.
Our current research explores the relationship between fuel composition, spray morphology, and particulate emissions with particular focus on the effects of the non-ideal mixing behaviour of ethanol and methanol in gasoline.