In order to satisfy the legislative requirements concerning the exhaust gas emissions, fuel consumption, and noise emissions of combustion engines, it is necessary to obtain insight in the mixture formation process and combustion. The mixture formation and consequently the combustion is mainly influenced by the injection process and the spray formation. The scope of the experimental investigation is the characterisation of the momentum, mass and energy exchange between the injected liquid fuel and the ambient gas phase. For the experimental investigations of the two phase flows a high pressure chamber had been developed, which enables the investigation of spray development and combustion at typical pressures and temperatures in Diesel engines (pmax = 50 bar, Tmax = 800 K). The high pressure chamber allows the mounting and experimental investigation of commonly used multi hole nozzles.

Determination of the time slope and mass of the injected fuel with a fuel injection meter (Bosch tube).

Determination of fuel jet integral dimensions (penetration, spray angle):

• Time slope of liquid fuel spray penetration and angle by means of the 2D-Mie scattering light technique.
• Time slope of gaseous fuel spray penetration and angle by means of the 2D-Schlieren and shadow technique.
• Determination of the evaporation characteristics of high pressure Diesel injection systems by means of a combined 1D-Raman / Mie scattering technique.

Determination of local spray dimensions as droplet size and velocity:

• Local determination of droplet size and velocity distributions

Time slope of the soot concentration by means of the 1D-light extinction technique

Investigation of the influence of the fuel composition (1 and 2 component model fuels) on the spray and mixture formation process.