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 />
Figu ure 5.6:<br />
Tange ential Velocity for r<br />
Intake e port 50% Closed d.<br />
Chapter 5<br />
wall-jet pr<strong>of</strong>ile in beca ause the pr<strong>of</strong>ille<br />
line has a smmall<br />
curvaturee<br />
from origin tto<br />
larger ra adial positions.<br />
However, tthe<br />
pr<strong>of</strong>ile typpe<br />
cannot be cconcluded<br />
herre<br />
in the absence a <strong>of</strong> me easurement daata<br />
near the cyylinder<br />
wall. CComparing<br />
V <br />
pr<strong>of</strong>iles in figures 5.1 1, 5.4 <strong>and</strong> 5.66<br />
it can be seeen<br />
very clearlyy<br />
that with thhe<br />
increase e in intake por rt closure, a soolid<br />
body rotaation<br />
pr<strong>of</strong>ile (iif<br />
the tangentiial<br />
velocity pr<strong>of</strong>iles at z <strong>and</strong> downstrream<br />
is assummed<br />
to be a foorced<br />
vortex) is<br />
3 attained d by the flow w at downstreeam<br />
positions.<br />
This pr<strong>of</strong>ilee<br />
moves in thhe<br />
upstream m direction as s the piston coontinues<br />
to inccrease<br />
the intake<br />
port closurre.<br />
The axia al velocity at z is higher thhan<br />
at 25% port<br />
closure (FFigure<br />
5.7). Thhe<br />
1<br />
distribu ution <strong>of</strong> V attains<br />
a jet-likke<br />
pr<strong>of</strong>ile for all the measuring<br />
positionns<br />
z<br />
through hout the cylind der cross-sectiions.<br />
The pr<strong>of</strong>file<br />
has a broaad<br />
central peaak.<br />
With th he decay in swi irl, for positionns<br />
z <strong>and</strong> z , thhe<br />
V pr<strong>of</strong>ile becomes nearrly<br />
4 5 z<br />
uniform m. However, due to exit contraction the jet-like ppr<strong>of</strong>ile<br />
for V Vz enhance es again at z . Analogous too<br />
V , with thee<br />
intake port cclosure<br />
a jet-likke<br />
6 <br />
pr<strong>of</strong>ile <strong>of</strong> axial velo ocity is introdduced<br />
at dowwnstream<br />
possition<br />
<strong>and</strong> thhis<br />
distribu ution pr<strong>of</strong>ile moves m to upsstream<br />
positioons<br />
with morre<br />
port closurre<br />
(Figures s 5.2, 5.5 <strong>and</strong> 5.7). 5<br />
114<br />
Effect <strong>of</strong> Piston Position
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