Due to increasingly stringent emission standards worldwide and the targets for net zero-emission mobility, the attention of academic and industrial R&D is drawn on research of alternative fuels The blending of fossil diesel by oxygenated fuel is a productive method to inhibit soot formation. A valid approach to reduce exhaust emissions is to increasing the overall percentage of the fuel’s oxygen content. This is achieved by blending oxygenated compounds into conventional fuels. The scope of the experimental investigation is the characterisation of alternative fuel spray combustion at engine relevant conditions and the development of novel diesel surrogate. For these experimental investigations a built in-house high-pressure combustion chamber is used, which enables the investigation of spray development and combustion typical pressure and temperature conditions in Diesel engines (pmax = 100 bar, Tmax = 1000 K). The high-pressure chamber also allows the mounting and experimental investigation of commonly used multi hole nozzles.

For a highly accurate determination of the injected fuel quantity and injection rate an IAV Cross-Injection Analyzer is utilized.

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

• temporal evolution of liquid fuel spray penetration and cone angle by 2D-Mie-Scattering techniques

• temporal evolution of gaseous fuel spray penetration and angle by 2D-Schlieren and Shadowgraphy techniques

Determination of fuel spray combustion characteristics:

• temporal evolution of flame lift-off length and integral OH* intensity with the measurement of ignition delay OH* chemiluminescence

• local determination of soot volume fraction (fv) and temporal soot mass distribution by DBI light extinction technique

Future research will focus on the influence of the fuel composition (1 and 2 component model fuels) on the spray combustion process and the development of novel diesel surrogates.