The Hydra 1 engine test cell is utilised for fundamental studies of in-cylinder air, liquid and vapour fuel mixture preparation characteristics in modern combustion systems. Laser Doppler anemometry (LDA) and phase Doppler anemometry (PDA) are applied to airflows and fuel sprays within the cylinder under motored engine operation.
Several means of optical access to the chamber are available. These include fused silica piston windows, cylinder liners, cylinder bore annular sections, spark plug windows and a specifically modified 'three-windowed' cylinder head that allows access to the pent-roof of the chamber. In addition, the study of fuel injector characteristics is realised within a quiescent, atmospheric pressure chamber.