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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 6.15:<br />

Snapshot t <strong>of</strong> Velocity<br />

Magnitu ude (a) RNG<br />

k Model M T.I 1% (b)<br />

RNG k Model T.I<br />

10% (c) RSM R T.I 10%.<br />

velocity y deficit regio on near the cyylinder<br />

axis coompared<br />

to RRSM.<br />

At z , thhe<br />

6<br />

RNG k model with T.I 10% % case prediccts<br />

a jet-like velocity pr<strong>of</strong>iile<br />

whereas s the T.1 1% case<br />

gives a fullly<br />

developed aaxial<br />

velocity ppr<strong>of</strong>ile.<br />

6.2.3<br />

Velocity Magnitudde<br />

The con ntour plots fo or the velocityy<br />

magnitude iis<br />

shown in ffigure<br />

6.15. Thhe<br />

plots do oes not show the data averraged<br />

over all the time stepps<br />

but is insteaad<br />

just an instantaneous<br />

numerical ssnapshot<br />

<strong>of</strong> thhe<br />

flow predicction<br />

by all thhe<br />

aforeme entioned simu ulation cases affter<br />

0.05s floww<br />

time.<br />

(a)<br />

(b)<br />

(c)<br />

From fi igure 6.15 for all the simulaation<br />

cases, it ccan<br />

be seen thhat<br />

there existss<br />

a<br />

large flo ow separation n at the wall wwhen<br />

the floww<br />

enters the ccylinder.<br />

This is<br />

obvious sly due to th he 90 bendd<br />

that exists between the outlet <strong>of</strong> thhe<br />

converg gent section <strong>and</strong> a the flow ccylinder.<br />

This wall flow sepparation<br />

regioon<br />

exists ap pproximately between b one tto<br />

two diametter<br />

lengths along<br />

the cylindeer.<br />

X<br />

Y<br />

Z<br />

Chapter 6<br />

157<br />

<strong>Numerical</strong> Modeling

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