Ricardo has throughout its history been highly active in the field of combustion research, improving the understanding of fundamentals of combustion systems and using this knowledge to create the next generation of more fuel efficient and cleaner burning engines. Non-intrusive experimental methods including phase doppler anemometry (PDA) particle image velocimetry (PIV) and laser-induced fluorescence (LIF) are used on optically accessed engines and fuel spray rigs to provide valuable data for the validation of predictive CAE methods. These include in-cylinder mixture formation and combustion modelling using the Ricardo VECTIS CFD and WAVE packages.