THE USE OF OILS FOR REDUCING HEAVY SEAS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600370168-5
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 4
• Document Creation Date: December 22, 2016
• Document Release Date: September 27, 2011
• Sequence Number: 168
• Publication Date: December 30, 1950
• Content Type: REPORT

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INFORMATION FROM.
FOREIGN DOCUMENTS OR RADIO BROADCASTS. CD NO.
CLASSIFICATION` CONFIDENTIAgNFIDENTIAL
Scientific - Geophysics, oceanology, wave
agitation
HOW
PUBLISHED Bimonthly periodical
WHERE
PUBLISHED Moscow - Leningrad
DATE
PUBLISHED Sep 1950
LANGUAGE
DATE OF
INFORMATION 1956
DATE DIST. Dec 1950
NO. OF PAGES 4
SUPPLEMENT TO
REPORT NO.
OR. TN. ONITIO NTAIIN WITH:I TOT Nu1INN OF O-IONAn ALT ..
? I:.C.. 31 AND Nt. AN AN01010. In TRANSMISSION 00 TNN I.TRATION
O CONTINTI IN ANT OA.... TO AN .... I.DNI... I...ON IN INO-
j;;. OT LAW. I'-0000CTIOX Of THIS -o0N II -NONIIITIO.
SOURCE
Izvestiya Akademii Nauk SSSR, Seriya Geograficheskaya i Geofiziches-
kaya, Vol XIV, No 5, 1950, pv 25-? 0.
THE USE OF OILS FOR REDUCING HEAVY SEAS
S. V.Dobroklonskiy, V. A. Tyumeneva
Marine Hydrophysics Inst, Acad Sci USSR
Submitted 15 Mar 1950
figures referred to are appended)
Seamen have long known that heavy seas can be calmed by pouring oil onto
the waves; however, the mechanism of this phenomenon has remained obscure until
recently. Quantitative measurements of this action were made first by R. N.
Ivanov (Izv. AN SSSR, Ser. Geograf. i Geofiz., No 3, pp 325-343, 1937; ibid.),,;
No 1. .29, 1938), whc, proved by a very refined method that the action of oily
substances was in no way connected with any decrease of surface tension between,
air and water (as was supposed in some hypotheses). Therefore, the damping
action was due to some sort of irreversible process caused by the presence of`
oil'films.
According to V. V. Shuleykin's hypothesis (Izv. AN SSSR, Ser. Geograf. 1'?'
Geofiz., No 3, pp 345-355, 1937; Physics of .the.Sea, Izd, AN SSSR, Moscow-
Leningrad, p. 671, 1941), this irreversible process must take place in the film
itself, the molecules of which are forced first to depart from the surface in
favor of the deeper rows when the water surface contracts on the crest of the
wave and then to rise again to the surface when the surface layer expands in
the wave trough. The larger and "more branched" the complex molecules of fatty
acids, the more-energy should be absorbed in this process by internal friction
in the damping film.
Ivanov forced thin water films covered on two aides with layers of salts
of fatty acids to alternately expand and contract, i.e., soap films,were
stretched in a special instrument between a hair registering the deformation
force and a rack oscillating exponentially. He obtained real "hysteresis
loops" for films. of various surface-active substances and determined. the amount
of energy absorbed in expansion and contraction of such films.
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GOWIDENIAL
Knowing these experimental. constants of Ivanov and knowing tine laws of con-
traction and expansion of the wave surface, Shuleykin calculated the amount of
energy which should be removed from waves by films of oil,,' surface-active sub-
stances. It turned out that for waves with low period (i.e., for steep, danger=ous waves), the energy absorbed was greater than that given the wave by the wind.
Despite the accuracy and conclusiveness of Ivanov's experiments, Levich
(Levich, V. G,, The Theory of Surface Effects, Izd, "Sovetskaya Nauka," 1941)
later published a mathematical work which represented a return to the old,
purely formalistic theory of Lamb (Lamb, G,, Hydrodynamics, Translation from the
6th English edition, 1932, GT'TI, Moscow-Leningrad, 19 7- on the mechanism of
damping by oil films. This theory proposes that the wave energy must be damped
simply because of the presence of foreign molecules on the water surface, these
foreign molecules. forming some sort of rigid boundary on the water, This "rigid"
boundary, it seems, must change the kinematics of the wave motion of the liquid
in comparison with the "free" wave and thus increase viscous friction losses in
the medium. Both Lamb and Levich, however, were drawn off from the physical ef-
fects which must occur in the surface film of foreign molecules and therefore
the Levich-Lamb hypothesis could not exp:4ain the considerable difference in the
damping capabilities of films of mineral, vegetable, and animal derivation. On
the other hand, the clamping effect of the "rigid boundary" is very much in the
background in comparison with -the effect of viscosity of the film substance it-
self (according to Shuleykin-Ivanov) at frequencies fairly close to the natural
one.
This work has the twofold aim of investigating the damping action of sur-
face-active substances directly on waves (and not on isolated Ivanov films) and
revealing the inconsistency of the formalistic Levich-Lamb hypothesis.
. The test unit which we constructed for the study consisted of a tank with
water, a wave producer, and an optical sounding unit which permitted us to meas-
ure the relative heights of waves at different points of the tank. The speed of
the wave producer motor could be varied from 15 to 60 revolutions per second.
This unit was used to study attentuation of waves of various frequencies on
a water surface which was covered with monomolecular films of oleic acid, fish
oil, and lauric acid.
Table 1 shows the results of measurements of frequencies, wave le:.gths, and
coefficients of wave damping for the substances studied, and also the calculated
values of the theoretical coefficients of damping and the damping constant. As
the "theoretical" damping coefficients, we have: Bp, corresponding to total ab-
sorption of energy in a viscous liquid for free wav2 motion and separately in
the film in correspondence with the Shuleykin-Ivanov hypothesis; B1, which gives
the wave damping due solely to the internal viscosity of the liquid, and Bzh,
which characterizes the absorption of energy by viscosity forces when the wave
according to Lamb is "nonfree" because of the presence of a rigid film on the
surface.
The damping constants found from theoretical formulas are shown in column 6
of the table, which also gives the average values for each substance. It is in-
teresting to note that the value of a for oleic acid (0.0102 erg'sec/sq cm) is
almost 150 times less than that obtained by Ivanov from experiments on soap
films for 0.01 normal sodium oleate (1.49 erg'sec/sq
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1
CONFIDENTIAL
Table 1. Experimental and Theoretical Values of Damping Coefficients
For'Frequency Interval From 16 to 60 Cycles
Meas-
Measured
Substance
ured
Fre-
quency
f (Cy-
cles)
Meas-
ured
Wave
Length
(cm)
Damping
Coeffi-
cients
B (per
cm)
Bp With
Average
Value of
a (per
cm)
Damping
Constant
a (erg-
sec) sq B1
cm) cm
per
BZh per
cm
Oleic acid
16.2
1.15
D.087
0.088
0.0098 0.
043
0.122
27.1
0.72
.),222
0.229
0.0097 0.
085
0.196
44,4
0.53
0.404
0.383
0.0110 0.
116
0.252
55.2
o.48
0,431
0.431
0.0102 0.
122
0.267
a = 0.0
102
(average)
Fish oil
21.8
0,89
J.134
0,142
0.0093 0.
060
0.152
28.0
0.71
0.248
0.231
0,0114 0.
085
0.196
40.3
0.55
0.369
0.376
0.0099 0.
116
0.250
I = 0.0102 (average)
Laurie
25.8
0.87
0.079
0.086
0.0043
0.049
0.138
acid
30.9
0.73
0.125
0.127
0.0052
0.067
0.164
39.0
0.73
0.192
0.180
0.0060
0.088
0.195
51.5
0.52
0.242
.0.220
0.0058
0.103
0.247
It ='0.0053 (average)
The difference in values is possibly caused by the fact that we used pure
fatty acids in our experiments while Ivanov used the salts of the fatty acids;
the strong polarity of . 3 alkaline elements entering into these salts undoubtedly
plays a very important role. The fact that similar strongly polar molecules can
rapidly form when even pure fatty acids come in contact with sodium ions, abun-
dantly present in sea water, is very important for practice.
The individual numbers of column 6 show that the values a for oleic acid
and fish oil do not reveal any systematic behavior with increasing frequency,
while the damping constant for lauric acid increases almost continuously for
the frequencies considered, giving the highest mean square error (12.6%) of all
the substances.. This result gives us reason to believe that the first two sub-
stances follow the Shuleykin-Ivanov hypothesis quite satisfactorily, while the
last is somewhat poorer.
Figures 1, 2, and 3 show the behavior of the theoretical damping coeffi-
cients Bp, B1, and Bzh with frequency. The measured values of B are encircled.
The graphs show that the experimental points for all the substances are close
to the curve corresponding to the coefficient Bp, while they are quite far re-
moved from the curves for B1 and B. A slight exception is the region of fre-
quencies above 30 cycles for lauric acid. Undoubtedly, we are dealing here with
processes which have nothing in common with those which exist in nature on the
surface of waves covered by oily substances which produce true surface solutions.
We separated laur'ic acid from a gasoline solution ("molecular lacquer"), and
therefore the inability of its molecules to move from layer to layer during the
passage of crests and troughs of waves became noticeable at the comparatively
higher frequencies.
Thus, comparison of experimental data with theoretical permits us to draw
the following conclusions:
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1. The behavior of the observed damping coefficient of waves for films of
the substances studied in the region of 15-60 cycles is satisfactorily ex-
plained by the Ivanov-Shuleykin theory; the waves are damping mainly by irre-
versible processes in the film of surface-active substances.
2. The "rigid boundary" on the wave surface adopted by the Levich-Lamb
theory produces only a minor effect which is not capable of damping waves under
natural conditions.
0.400
.0.100
IV~r
0 10 20 30 40 50 60 70
f (cps)
Figure 1. Coefficients Found From
Experiments of Wave Damping on a Water
Surface Covered With a Film of Oleic
Acid as a Function of Frequency and
Theoretical Damping Coefficients
B (1/cm)
Figure 2. Coefficients Found From
Experiments of Wave Damping on a Water
Surface Covered With a Film of Fish 0.200
Oil As a Function of Frequency and
Theoretical Damping Coefficients
B (l/cm)
0 10 20 30 40 f5(cps60
Figure 3. Coefficients Found From
Experiments of Wave Damping.on a Water
Surface Covered With a Film of Lauric
Acid as a Function of Frequency and
Theoretical Damping Coefficients
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