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
Tab ble 5.1:
Meas suring Positions.
Effec E ct of f Pistton
PPosiitionn
In this chapter c the effe ect of piston poosition
on the iin-cylinder
swirrling
flow durinng
the scav venging process is studied usinng
the stereoscoopic
particle immage
velocimettry
techniqu ue. The measure rements are conducted
at differrent
cross-sectioonal
planes alonng
the cylin nder length and d at piston posit itions covering tthe
air intake pport
by 0%, 25% %,
50% and d 75%.
In this experiment, st tereoscopic PIIV
measuremeents
are carrieed
out using thhe
same se etup as describ bed in Chapteer
3. The cylinnder
length is kept at 4D annd
measuring
positions are also kept the same as ddescribed
for L in Table 44.1
3
and also o given here in n Table 5.1.
Positioon
No.
The le ength and diameter
of e
measure ements. The opening of th
measure ements are co onducted at 4
cylinder
inlet/ intake e port
the cyli inder inlet. Th
thus pa artially closin
translat ted further by
translat ted again by 1
compar red to its posit
the wid dth of the cylin
has red duced by 3cm
1
exhaust pipee
is kept coonstant
for aall
he cylinder innlet
has a widtth
of 4 cm. Thhe
4 fixed pistonn
positions. For fully opeen
the pisston
is kept alligned
with thhe
lower end of
he piston is thhen
translatedd
inside the ccylinder
by 1cm
ng the inlet bby
25%. For 50% closuree
the piston is
1cm. In the nnext
step for 775%
port closuure,
the piston is
1cm with a tootal
translationn
of 3cm insiide
the cylindder
tion with fullyy
open intake port. This meeans
that at 755%
nder inlet is reeduced
to 1cmm
and the cylinnder
length also
m compared tto
4D. Howeever,
from thhe
experimenttal
1
In th his chapter and other o parts of th he thesis the cylinder
inlet is alsso
named as inttake
port analoggous
to scavengge
ports in
a Two-Stroke low speed marine
diesel engin ne.
z1
z2
z3
z4
z5
z6
Axial
Positions
( z/D )
0.963
1.489
2.016
2.542
3.068
3.595
Chapter 5
107
Effect of Piston Position