instantaneous volumetric wake analysis of locomotion … · total volume imaged was 14*14*10 cm....
TRANSCRIPT
11
22
Bro
oke
E.
Fla
mm
an
g,
Ge
org
e V
. L
au
de
r,
Da
nie
l R
. T
roo
lin,Tyso
n S
tra
nd
12
Museum
of C
om
para
tive Z
oolo
gy,
Harv
ard
Univ
ers
ity,
Cam
bridge, M
A, 02138, U
SA
. F
luid
Mechanic
s D
ivis
ion, T
SI In
corp
ora
ted, S
t. P
aul, M
N, 55126, U
SA
INS
TA
NTA
NE
OU
S V
OL
UM
ET
RIC
WA
KE
AN
ALY
SIS
OF
LO
CO
MO
TIO
N IN
TE
LE
OS
T F
ISH
ES
AB
ST
RA
CT:
Pre
vio
us s
tudie
s o
f th
e w
ake h
ydro
dynam
ics o
f fishes h
ave
been r
estr
icte
d to tw
o-d
imensio
nal dig
ital part
icle
im
age v
elo
cim
etr
y (
DP
IV)
slic
es b
y a
vaila
ble
technolo
gy.
B
y c
om
paring m
ultip
le s
lices, pre
vio
us
researc
hers
hypoth
esiz
ed the thre
e-d
imensio
nal str
uctu
re o
f th
e v
ort
ex w
akes
pro
duced b
y s
wim
min
g fis
hes. In tele
ost fishes, such a
s the b
lueg
ill s
unfish,
the h
om
ocerc
al ta
il pro
duces a
sin
gle
jet w
ith e
ach late
ral pass. U
sin
g
conventional tw
o-d
imensio
nal D
PIV
, vort
icity s
hed b
y the h
om
ocerc
al ta
il w
as
vis
ualiz
ed a
s tw
o c
ounte
r-ro
tating v
ort
ice
s w
hic
h w
ere
hypoth
esiz
ed to b
e
part
of a thre
e-d
imensio
nal ro
tating r
ing
thro
ugh w
hic
h a
jet of fluid
passed.
Now
, usin
g a
volu
metr
ic D
PIV
syste
m, w
e h
ave c
onfirm
ed that th
e thre
e-
dim
ensio
nal str
uctu
re o
f th
e v
ort
ex r
ing p
roduce
d b
y the h
om
ocerc
al ta
il fin is
indeed a
s p
redic
ted. In a
dditio
n, m
ultip
le late
ral passes o
f th
e tail
pro
duced a
lin
ked c
hain
of vort
ex r
ings. U
sin
g this
volu
metr
ic D
PIV
syste
m w
e w
ere
als
o
able
to insta
nta
neously
captu
re the thre
e-d
imensio
nal w
ake inte
ractio
ns o
f th
e d
ors
al and a
nal fins w
ith the c
audal fin in b
oth
liv
e fis
hes a
nd r
obotic
analo
gs.
HY
PO
TH
ES
IS 1
: E
ach
la
tera
l p
ass o
f th
e h
om
oce
rca
l ta
il p
rod
uce
s a
sin
gle
je
t o
f flu
id,
wh
ich
pa
sse
s t
hro
ug
h a
vo
rte
x
rin
g.
Mu
ltip
le la
tera
l p
asse
s
pe
rfo
rme
d d
urin
g s
wim
min
gp
rod
uce
a s
erie
s o
f lin
ke
d v
ort
ex
rin
gs.
(Fig
ure
fro
m L
au
de
r a
nd
D
rucke
r, 2
00
2)
HY
PO
TH
ES
IS 2
: V
ort
icity
pro
du
ce
d b
y t
he
do
rsa
l a
nd
a
na
l fin
s o
f a
sw
imm
ing
fis
h
inte
racts
with
th
at
pro
du
ce
d b
y
the
ca
ud
alf
in.
(Fig
ure
fro
m
Tyte
ll, 2
00
6)
Fig
. 1
Fig
. 2
Fig
. 3
Fig
. 1
. E
xp
erim
en
tal
arr
an
ge
me
nt
of
the
flo
w t
an
k,
lase
rs,
an
d v
olu
me
tric
im
ag
ing
syste
m f
or
ca
ptu
rin
g t
he
in
sta
nta
ne
ou
s v
olu
me
tric
wa
ke
b
eh
ind
fre
ely
sw
imm
ing
fis
he
s
an
d r
ob
otic t
ail
mo
de
ls. To
tal
vo
lum
e im
ag
ed
wa
s 1
4*1
4*1
0
cm
.
Fig
. 2
. V
olu
me
tric
3-c
om
po
ne
nt
ve
locim
etr
y (
V3
V)
vo
lum
etr
ic
flo
w im
ag
ing
trip
od
ca
me
ra
pro
be
ca
ptu
red
im
ag
e p
airs a
t 7
.25
Hz w
ith
a t
ime
of
35
00
us
be
twe
en
ea
ch
im
ag
e p
air a
t 1
2
bit r
eso
lutio
n.
Fig
. 3
. S
ch
em
atic
rep
rese
nta
tio
n o
f 3
D
pa
rtic
le id
en
tifica
tio
n.
Pa
rtic
le im
ag
es f
rom
th
e
left
ima
ge
(L
) a
re
rep
rese
nte
d b
y w
hite
,p
art
icle
im
ag
es f
rom
th
e
rig
ht
ima
ge
(R
) a
re
rep
rese
nte
d b
y r
ed
, a
nd
p
art
icle
im
ag
es f
rom
th
e
top
im
ag
e (
T)
are
re
pre
se
nte
d b
y b
lue
.T
he
ce
ntr
oid
of
the
trip
let
rep
rese
nts
th
e x
an
d y
loca
tio
n,
the
an
d t
he
siz
e
giv
es t
he
z lo
ca
tio
n.
(Fig
ure
fro
m T
roo
lin a
nd
L
on
gm
ire
, 2
00
9).
RE
FE
RE
NC
ES
:
La
ud
er,
G.V
. a
nd
E.G
. D
rucke
r. (
20
02
) F
orc
es,
fish
es,
an
d f
luid
s:
Hyd
rod
yn
am
ic m
ech
an
ism
s o
f a
qu
atic lo
co
mo
tio
n.
Ne
ws P
hysio
l S
oc 1
7:2
35
-2
40
Tro
olin
D.R
. a
nd
E.K
. L
on
gm
ire
. (2
00
9)
Vo
lum
etr
ic v
elo
city m
ea
su
rem
en
ts o
f vo
rte
x r
ing
s
fro
m in
clin
ed
exits.
Exp
Flu
ids
DO
I 1
0.1
00
7/s
00
34
8-0
09
-07
45
-z
Tyte
ll, E
.D.
(20
06
) M
ed
ian
fin
fu
nctio
n in
blu
eg
ill
su
nfish
Le
po
mis
ma
cro
ch
iru
s:
str
ea
mw
ise
vo
rte
x
str
uctu
re d
urin
g s
tea
dy s
wim
min
g.
J E
xp
Bio
l 2
09
:15
16
-15
34
Fig
. 4
. (A
) R
ob
otic s
imp
lifie
d h
om
oce
rca
l ta
il m
od
el in
la
se
r vo
lum
e a
nd
(B
) vo
lum
etr
ic
reco
nstr
uctio
n o
f w
ake
pro
du
ce
d.
No
te h
ow
do
wn
str
ea
m e
dg
e c
on
str
icts
je
t (w
hite
arr
ow
s).
ME
TH
OD
S:
Fig
. 8
. (A
, to
p)
Vo
lum
etr
icre
co
nstr
uctio
n o
f w
ake
of
a
blu
eg
ill s
un
fish
sw
imm
ing
fa
r b
ack e
no
ug
h in
vo
lum
e t
o s
ee
w
ake
pro
du
ce
d b
y t
he
do
rsa
l fin
(o
utlin
ed
in
re
d).
(B
, b
ott
om
) P
lan
ar
slic
e (
XY
) th
rou
gh
vo
rte
x c
au
se
d b
y d
ors
al fin
, co
lore
d b
y z
vo
rtic
ity.
Ta
ng
en
tve
cto
rs a
re d
isp
laye
d a
nd
in
dic
ate
dire
ctio
n a
nd
ve
locity
of
flo
w,
with
me
an
str
ea
m f
low
ve
locity s
ub
tra
cte
d.
AB
Fig
. 5
. (A
) L
ive
blu
eg
ill s
un
fish
sw
imm
ing
in
la
se
r vo
lum
e a
nd
(B
) vo
lum
etr
ic
reco
nstr
uctio
n o
f w
ake
pro
du
ce
d (
at
40
% t
ran
slu
ce
ncy).
* =
tra
ilin
g e
dg
e v
ort
ice
s
se
pa
ratin
g f
rom
ta
il fin
.
AB
AB
Fig
. 6
. (A
) L
ive
cic
hlid
sw
imm
ing
in
la
se
r vo
lum
e a
nd
(B
) vo
lum
etr
ic r
eco
nstr
uctio
n o
f w
ake
pro
du
ce
d.
AB
Fig
. 7
. (A
) R
ob
otic b
lue
gill
ho
mo
ce
rca
l ta
il m
od
el in
la
se
r vo
lum
e a
nd
(B
) vo
lum
etr
ic
reco
nstr
uctio
n o
f w
ake
pro
du
ce
d b
y t
he
do
rsa
l (r
ed
), a
na
l (b
lue
) a
nd
ca
ud
al (g
ree
n)
fin
s.
A B
-5.0
5.0
0-1
Z V
ort
icity (
s)
* *
CO
NC
LU
SIO
NS
:
The a
bili
ty to c
aptu
re a
n
insta
nta
neous s
napshot of th
e
com
ple
te w
ake s
tructu
re
pro
duced b
y a
sw
imm
ing fis
h
rem
oves the p
ote
ntial err
or
involv
ed w
ith p
revio
us
technolo
gie
s, w
here
re
searc
hers
had to inte
gra
te
multip
le d
ata
sets
to p
roduce
a 3
D s
tructu
re. U
sin
g this
new
technolo
gy,
we h
ave
confirm
ed that hom
ocerc
al
tails
pro
duce a
series o
f lin
ked
ring v
ort
ices d
uring s
teady
sw
imm
ing. W
e h
ave a
lso
been a
ble
to identify
dors
al
and a
nal fin w
ake s
tructu
res
and a
re b
egin
nin
g to b
uild
a
better
unders
tandin
g o
f how
th
ey inte
ract w
ith the w
ake
pro
duced b
y the c
audal fin.
An
ag
lyp
h o
f F
ig.
6B
, vie
w w
ith
3D
gla
sse
s.
DO
RS
AL
FIN
JE
T
FIS
H B
OD
Y