Experimental and Numerical Study of Swirling ... - Solid Mechanics
Experimental and Numerical Study of Swirling ... - Solid Mechanics
Experimental and Numerical Study of Swirling ... - Solid Mechanics
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Experi imental <strong>and</strong> <strong>Numerical</strong> N Stud dy <strong>of</strong> <strong>Swirling</strong> g Flow in Scaveenging<br />
Processs<br />
for 2-Stroke<br />
Marin ne Diesel Engin nes<br />
Figure e 5.12:<br />
Averaged d 3D Velocity<br />
Field at z 25% port<br />
6<br />
closure (C Color Contour<br />
represent t the Normalized d<br />
out <strong>of</strong> the e plane velocity<br />
compone ent Vz / V . b<br />
Fig gure 5.13:<br />
Averaged<br />
3D Velocit ty<br />
Fiel ld at z 50% port<br />
1<br />
closu ure (Color Conto our<br />
repr resent the Norma alized<br />
out <strong>of</strong> the plane velo ocity<br />
com mponent Vz / V . b<br />
50% Por rt Closure<br />
Chapter 5<br />
For 50% % port closure,<br />
the three dimmensional<br />
veloocity<br />
distributtion<br />
is discusseed<br />
only for r positions z <strong>and</strong> a z .<br />
1 5<br />
At z th he axial velocit ty has a jet-likee<br />
pr<strong>of</strong>ile. The peak <strong>of</strong> the prr<strong>of</strong>ile<br />
is broadder<br />
1<br />
<strong>and</strong> the e gradients are e spatially moore<br />
smooth annd<br />
distinct (Fiigure<br />
5.13). Thhe<br />
in-plane e velocity vectors<br />
indicate tthat<br />
the tangeential<br />
velocityy<br />
at one side <strong>of</strong><br />
the vort tex is higher than<br />
the otherr<br />
due to the efffect<br />
<strong>of</strong> wall. Itt<br />
must be noteed<br />
that in figure 5.13, the peak in aaxial<br />
velocity does not coiincide<br />
with thhe<br />
vortex core. Repeate ed measuremeents<br />
<strong>and</strong> alsoo<br />
variation inn<br />
time betweeen<br />
pulses for f PIV measu urement resultted<br />
in the simmilar<br />
behaviorr.<br />
The reason <strong>of</strong><br />
this non n-coincidence for being stattistical<br />
or somme<br />
fluid characcteristic<br />
is could<br />
not be found f out by the t author.<br />
The axial<br />
velocity has s almost a uniiform<br />
distribuution<br />
at cylindder<br />
cross-sectioon<br />
at z (F Figure 5.14). The T regions wwith<br />
maximumm<br />
<strong>and</strong> minimmum<br />
values aare<br />
5<br />
119<br />
Effect <strong>of</strong> Piston Position