Combustion and emissions formation in direct injected engines are both strongly affected by the development of the fuel spray. This means that understanding of spray breakup, vaporization, mixing and turbulent combustion is critically important for advancement of theory and for engine development.
In an engine many parameters vary with time, often simultaneously; cylinder pressure, cylinder temperature, gas motion, and turbulence for example. When a fuel spray is injected into an engine flow, it is difficult to isolate one process from another in order to understand how combustion is affected by the many possible variables. The advantage of a spray research chamber is that one can control the ambient conditions and isolate each important variable in order to investigate the effect it has on spray combustion. To mimic these effects one must vary the ambient pressure and temperature, and the fuel pressure and temperature.
The properties that one studies include spray breakup, drop size distributions and drop velocities, spray penetration, vaporization, air entrainment, turbulence, mixing, combustion, soot formation and oxidation, and the effect of interactions between more than one spray and between a spray and a wall. Such investigations advance basic understanding and the help in the development of numerical models.
The G cell houses two specialized spray chambers where one can study various properties of combusting transient fuel sprays.