Experimental and Numerical Study of Swirling ... - Solid Mechanics

Experimental and Numerical Study of Swirling Flow in Scavenging Process for 2-Stroke
Marine Diesel Engines
Figure 4.2:
LDA Measurements
along an arc behind the
blades (a) mean radial
velocity profile (b) mean
tangential velocity profile
(Schnipper, 2010).
Chapter 4
At downstream radial position of 180 mm, the relative variation in
magnitudes of individual velocity components reduces significantly. A
possible reason is that the flow at a radial position of 170 mm enters the
contraction region which will have a damping effect to any variations/
fluctuations in velocity and the flow at nearby upstream positions also feels
the presence of the contraction section.
(m/s)
V r
(m/s)
V
(a)
(b)
The measurements conducted along the two arcs behind the blades as
mentioned in figure 3.18 are shown in figure 4.2. Where is the angular
location of the measurement point on a given arc. The negative values of the
velocity components are due to the orientation of LDA laser beams. Each
half length of the error bar is one standard deviation. The results show that at
a radial distance of 230 mm (the trailing end of the blade is approximately at
51
Swirling Flow in a Pipe