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

Experi imental and Numerical N Stud dy of Swirling g Flow in Scaveenging
Processs
for 2-Stroke
Marin ne Diesel Engin nes
Figure
6.3:
Com mparison of
Normalized
Tangen ntial
Vel locity Profile at z . 1
Figure
6.4:
Com mparison of
Normalized
Tangen ntial
Vel locity Profile at z . 2
Chapter 6
compar red to experim mental data. TThe
effect of ddifferent
T.I leevels
defined at
the inle et can be seen very clearly fo for the RNG k model. At T.I 10%, thhe
predicte ed tangential velocity v profilles
show a rappid
increase inn
the size of thhe
vortex core c from z to o z comparedd
to T.I 1% until
z where thhey
both prediict
3 4 6
the sam me vortex core size. Howeverr,
it can be seeen
that for thee
two T.I valuees,
the diff ference in the predicted tanggential
velocitty
gradient in the core regioon
remains s at all positions
i.e. steeper gradients in tthe
core regionn
is predicted at
lower T.I. T
For the e RSM, the tendency
to preedict
the annuular
region off
the tangentiial
velocity y profile seems s better than tthe
RNG k
model but still the profilles
do not follow the ex xperimental daata
in that reggion.
For posiitions
z and z ,
2 3
the tan ngential veloci ity gradient inn
the core region
shows ggood
agreement
with th he experiment tal data, howwever,
at otheer
positions itt
shows a pooor
agreement.
152
Numerical Modeling