INAUGURAL–DISSERTATION zur Erlangung der Doktorwürde der ...

56 4. Results and Discussion
Fig. 4.1: Photograph of the water
spray formation.
Fig. 4.2: Schematic diagram of spray
with measurement positions.
4.1.1 Experimental Setup
Experiments have been carried out by Dr. R. Wengeler at BASF, Ludwigshafen, where
a water spray is injected into a cylindrical spray chamber. The carrier gas is nitrogen
at room temperature. Three different experiments are conducted by keeping the
spray inflow rate at 80, 150 and 200 kg/h while the gas volumetric flow rate is fixed
at 200 Nm 3 /h. The droplet size distribution is recorded at sections of 0.14, 0.54,
and 0.84 m distance from the nozzle exit using laser Doppler anemometry (LDA).
Measurements at 0.14 m are taken as a starting point for initial data generation for
computations. Figure 4.1 shows the photograph of water spray formation in experiment,
and the schematic representation of spray with dimensions and measurement
positions in experiment is shown in Fig. 4.2. The spray column has a diameter of 1 m.
The present simulations concern the experimental data generated using the Delavan
nozzle SDX-SE-90 with an internal diameter of 2 mm and an outer diameter of 12 mm
at the nozzle throat and 16 mm at the top.
4.1.2 Initial Data Generation
The experimental data provide the cumulative volume frequency of different droplet
sizes. These volume frequencies are converted into surface frequencies by dividing the
individual volume frequency with the corresponding diameter. Figure 4.3 shows the
surface frequencies at the distance of 0.14 m (left) and 0.54 m (right) from the nozzle
exit, respectively, as obtained from the experimental data. At 0.14 m distance away
from the nozzle, there is a higher number of small-sized droplets shown in the left side
of Fig. 4.3, whereas at 0.54 m distance, an increased number of larger size droplets
is found, see right part of Fig. 4.3. The droplet velocities are not measured in the