Resistance tests were conducted in the High Speed Water Tunnel on 2-in. diameter models of the 5-in. A. S. Projectile, Ex 30, and the 6-in. Projector Charge, Ex 1. The 5-in. A. S. Projectile was found to

have a terminal sinking velocity of 39.4 fps with armed nose fuse and 35.7 fps for the flat nose projectile without fuse. The terminal sinking

velocity for the 6-in. Projector Charge was 34.3 fps with armed nose fuse and 32.6 without the fuse

Kermeen, R. W.

Caltech Authors - Main

Department of the Navy 
Bureau of Ordnance 
Contract NOrd 961 Z. 
RESISTANCE TESTS 
ON THE 5-IN. A. s .. PROJECTILE ,AND 
'J'HE 6-IN. PROJE 'CTOR CHARGE 
by 
R. W. Kermeen 
Hydrodynamics Laboratory 
California Institute of Technology 
Pasadena, California 
Report No .. E-lZ.. 5 
April 15, 1952 
Copy No. 53 
J. T. McGraw 
Project Supervisor 
ABSTRACT 
Resistance tests were conducted in the High Speed Water Tunnel 
on 2-in. diameter models of the 5-in . .A.. S. Projectile, Ex 30, and the 
6 -in. Projector Charge, Ex 1. The 5 -in. A. S. Projectile was found to 
have a terminal sinking velocity of 39.4 fps with armed nose fuse and 
35.7 fps for the flat nose projectile without fuse. The terminal sinking 
velocity for the 6-in. Projector Charge was 34.3 fps with armed nose 
fuse and 32.6 without the fuse. 
MODELS 
The 2-in. diameter model of the 5 -in. A. S. Projectile Ex 30 (Fig. 1) 
was constructed to specifications of BuOrd Sketch No.239585 with the ex-
ception of the fins which were set at zero degrees instead of the 7° shown 
in the sketch. 
The 2-in. diameter model of the 6-in. Projector Charge Ex 1 {Fig. 
1) was constructed to specifications of BuOrd Sketch No. 239308.. The 
10° fin angle was changed to zero degrees. 
Tests were made with the flat nose models and with the armed Ex 
102 nose fuse with vanes jettisoned. 
DISCUSSION OF RESULTS 
Resistance tests of the 6-in. Projector Charge and the 5-in~ A. S. 
Projectile were made in the High Speed Water Tunnel and have been re-
ported previously in Memorandum Report EM-12. 2( l). The results 
showed variations in drag caused by the tunnel balance. Because of the 
interaction of pitching moment and drag, which arises from the balance 
geometry, variations in the results with model support location were 
observed. These va:rlations amounted to as much as 18 per cent of the 
total drag. It should be pointed out that such a large drag-pitching mo-
ment interaction is not usually observed. The extreme slenderness 
ratio of the models tested produced large moments which in turn caused 
relatively high drag errors. 
A pitching moment balance was constructed so that the drag results 
could be separated from the force due to pitching moment. A series of 
-z-
runs was made on the 5 -in. A. S. Projectile supported at several differ-
ent points along the body. The pitching moment varied with the support 
point, as suspected. However, the drag curves were identical when cor-
rected for the pitching moment interaction. ( 2) 
The results of the runs, using the three -component balance, to-
gether with the pitching moment balance, are shown in Fig. 2. The maxi-
mum Reynolds number of 10.5 x 1 o6 based on model length is close enough 
to the Reynolds numbers of the prototypes to allow a short extrapolation 
of the drag curves. 
From the curves shown in Fig. 2 and assuming a weight in sea-
water of 51.9 lbs,(3) the calculated terminal sinking rates of the 5-in. 
A. S. Projectile are 35.7 fps for the flat nose case and 39.4 fps with the 
armed nose fuse. Tests of this shape, conducted at the Alden Hydraulic 
Laboratory,(3) indicated an average drag coefficient of 0.30 for the flat 
nose model operating without a cavity. The Alden Laboratory data gives 
a calculated sinking rate of 36.0 fps. which agrees fairly well with the 
tunnel data. 
Using the estimated weight in sea water of 40.4 lbs (BuOrd sketch 
No. 239308) for the 6-in. Projector Charge, one finds terminal sinking 
• 
velocities of 32.6 fps for the flat nose projectile and 34. 3 fps with the 
artned Ex 102 nose fuse. Ave:rage drag coefficients of 0.280 with flat 
nose an-d 0.185 with armed nose fuse are reported by the Alden Hydraulic 
Laboratory.(4) Sinking rates calculq.tedlrom this data were 27.2 and 
33.4 fps, respectively. 
-3-
--- ~------
K 
Fig. l - Two -inch diameter models of the 6 -in. Projector Charge, Ex l (top) 
and the 5 -in. A. S. Projectile, Ex 30 (bottom) 
. 80 
. 70 
.60 
.50 
0 
.40 (_) 
1--: z 
w 
0 .30 
Li: 
u... 
w 
0 
(.) 
<!) 
<t 
a:: 
.20 Cl 
. I 0 
~5- IN. A.S . PROJECTILE 
~ 
"' _f '"' 
""' 
NO FUSE 
-cD ' '"' «; _£:) FUSE 
v I'-"-' w----- --- --~ f> 
!;;;, r::. 
~ ~ ~ 
~ 
t- NO FUSE ,.,. 
(;:, -.A. ~ ~ 
~ - - FUSE 
6-IN. PROJECTOR CHARG E 
2 3 4 5 6 7 8 9 10 20 
REYNOLDS NUMBER X 10- 6 
Fig. 2 - Drag coefficient vs. Reynolds number for models of 
5-in. A. S. Projectile and 6-in. Projector Charge 
30 
-4-
APPE~DIX 
Increased Drag Due to Shroud and Fin Sing 
During the drag runs with both the 5-in. A. S. Projectile and the 
6-in. Projector Charge, it was noted that at certain velocities a clear 
singing note could be heard coming from the model tail. Notations were 
made on the data and it was later observed that in every case where sing-
ing was noted, except for the higher freq~encies, there was a small but 
distinct increase in drag. Singing of this type has been observed before 
in the High Speed Water Tunnel on hydrofoils. As reported by Gongwer,(S) 
these notes caused by the Karman vortex street would fade as the velocity 
of the water was increased, disappear, and then reappear as a note of 
higher frequency. Two points of increased drag corresponding to this fin 
singing can be seen on the curves for the 5 -in.A. S. Projectile (Fig. 2) at 
Reynolds numbers of 3.5 and 7.0 x 10
6
. 
REFERENCES 
1. Kermeen, R. W. ,"Resistance Tests on a Series of Flat Nose Bodies, 
the 6-in. Projector Charge, the 5-in. A. S. Projectile", 
Hydrodynamics Laboratory, California Institute of Technology, 
Memorandum Report No. EM 12. 2, Aug. 1951. 
2. Kermeen, R. W., "Pitching Moment Balance for the High Speed Water 
Tunnel", Memorandum Report No. EM 12.4, April 15, 1952. 
3. "Underwater Performance of 1-1/4-in. Model of the 5-in. A. S. Pro-
jectile, Ex 30," Alden Hydraulic Laboratory Report No. 21, 
Feb. 1951. 
4. "Water Entry and Underwater Performance Characteristics of the 
1-1/4-in. Model of the 6-in. Projector Charge, Ex 1," 
Alden Hydraulic Laboratory Report No. 23, April 1951. 
5. Gangwer, <;. P . • , "A Study of Vanes Singing in Water". Aerojet Engi-
neering Corporation, Sept. 1951. 
Copy No. 
1 
:z. 
3-4 
5-7 
8-12 
13-15 
16 
17-18 
19-ZO 
21-22 
23-24 
25-26 
27 
:Z.8 
29 
30 
31-32 
33-34 
35-44 
45 
46 
47 
48 
49 
50 
DISTRIBUTION LIST FOR NOrd 961Z 
California Institute of Technology 
Pasadena, California 
Name and Address 
Chief, Bureau of Ordnance, Navy Department, Washington 
Z.5, D. C., Attention: Code Re6a 
Code Re3d 
Code Ad3 
Chief, Bureau of Aeronautics, Navy Department, 
Washington 25, D. C., Attention: Code De3 
Chief, Bureau of Ships, Navy Department, ··washington 
25, D. C. 
Chief of the Office of Naval Research, Navy Department 
Washington Z5, DP C., Attention: Code 438 
Office of Naval Research, Los Angeles Branch, 
1030 East Green Street, Pasadena, California 
Director, David Taylor Model Basin, Washington 7, D. C. 
Commanding Officer, NaVal Torpedo Station, Newport, R, : 
Commander, Naval Ordnanee Test Station, Inyokern, 
China Lake, California 
Commander, Naval Ordnance Test Stationr Pasadena 
Annex, 3202 East Foothill Blvd., Pasadena 8, California 
Commander, Naval Ordnance Laboratory, White Oak 
Silver Spring 19, Maryland 
Director, Stevens Institute of Technology, 711 Hudson 
Street, Hobo}ten, N. J.; Via: Bureau of Aeronautics Rep,.. 
resentative, c/o Bendix Aviation Corp., Eclipse -Pioneer 
Division, Teterboro, New Jersey 
Director, Ordnance Research Laboratory, Penn. State 
College, State College, Pennsylvania 
Alden Hydraulic Laboratory, Worcester Polytechnic 
Institute, Worcester, Mass. Via: Inspet;tor of Naval 
Materiel, Summer Street, Boston 10, Mass. 
Inspector of Naval Materiel, Development Contract 
Section, 1206 South Santee Street, Los Angeles, Calif. 
Superintendent, U.S. Navy Postgraduate School, 
Annapolis, Maryland 
Director, U.S. Naval Elect:ronics Laboratory, Point 
Lama, San Diego; California 
British Joint Services Mission, Navy Staff: Via: Chief• 
Bureau of Ordnance, Navy Department, Washington 25, 
D. C., Attention: Code AdS 
Executive Secretary, Research and Development Board 
National Defense Building, Washington, D. C. 
Dr. Lindvall, Chairman, Division of Engineering, Cali-
fornia Institute of Technology 
Dr. E. Bromberg, Office of Naval Research, Mechanics 
Branch 
Underwater Ordnance Dept., Naval Ordnance T~tst Sta., 
Thomp son Laboratory, Grand Ave., Pasadena, Calif. 
At tn: Code P80 
Attn : Code P 8001 
Commander, Submarine Development Group TWO, 
c/o Fleet Post Office, New York, N. Y. 


English

Resistance Tests on the 5-in. A. S. Projectile and the 6-in. Projector Charge

Department of the Navy 
Bureau of Ordnance 
Contract NOrd 961 Z. 
RESISTANCE TESTS 
ON THE 5-IN. A. s .. PROJECTILE ,AND 
'J'HE 6-IN. PROJE 'CTOR CHARGE 
by 
R. W. Kermeen 
Hydrodynamics Laboratory 
California Institute of Technology 
Pasadena, California 
Report No .. E-lZ.. 5 
April 15, 1952 
Copy No. 53 
J. T. McGraw 
Project Supervisor 
ABSTRACT 
Resistance tests were conducted in the High Speed Water Tunnel 
on 2-in. diameter models of the 5-in . .A.. S. Projectile, Ex 30, and the 
6 -in. Projector Charge, Ex 1. The 5 -in. A. S. Projectile was found to 
have a terminal sinking velocity of 39.4 fps with armed nose fuse and 
35.7 fps for the flat nose projectile without fuse. The terminal sinking 
velocity for the 6-in. Projector Charge was 34.3 fps with armed nose 
fuse and 32.6 without the fuse. 
MODELS 
The 2-in. diameter model of the 5 -in. A. S. Projectile Ex 30 (Fig. 1) 
was constructed to specifications of BuOrd Sketch No.239585 with the ex-
ception of the fins which were set at zero degrees instead of the 7° shown 
in the sketch. 
The 2-in. diameter model of the 6-in. Projector Charge Ex 1 {Fig. 
1) was constructed to specifications of BuOrd Sketch No. 239308.. The 
10° fin angle was changed to zero degrees. 
Tests were made with the flat nose models and with the armed Ex 
102 nose fuse with vanes jettisoned. 
DISCUSSION OF RESULTS 
Resistance tests of the 6-in. Projector Charge and the 5-in~ A. S. 
Projectile were made in the High Speed Water Tunnel and have been re-
ported previously in Memorandum Report EM-12. 2( l). The results 
showed variations in drag caused by the tunnel balance. Because of the 
interaction of pitching moment and drag, which arises from the balance 
geometry, variations in the results with model support location were 
observed. These va:rlations amounted to as much as 18 per cent of the 
total drag. It should be pointed out that such a large drag-pitching mo-
ment interaction is not usually observed. The extreme slenderness 
ratio of the models tested produced large moments which in turn caused 
relatively high drag errors. 
A pitching moment balance was constructed so that the drag results 
could be separated from the force due to pitching moment. A series of 
-z-
runs was made on the 5 -in. A. S. Projectile supported at several differ-
ent points along the body. The pitching moment varied with the support 
point, as suspected. However, the drag curves were identical when cor-
rected for the pitching moment interaction. ( 2) 
The results of the runs, using the three -component balance, to-
gether with the pitching moment balance, are shown in Fig. 2. The maxi-
mum Reynolds number of 10.5 x 1 o6 based on model length is close enough 
to the Reynolds numbers of the prototypes to allow a short extrapolation 
of the drag curves. 
From the curves shown in Fig. 2 and assuming a weight in sea-
water of 51.9 lbs,(3) the calculated terminal sinking rates of the 5-in. 
A. S. Projectile are 35.7 fps for the flat nose case and 39.4 fps with the 
armed nose fuse. Tests of this shape, conducted at the Alden Hydraulic 
Laboratory,(3) indicated an average drag coefficient of 0.30 for the flat 
nose model operating without a cavity. The Alden Laboratory data gives 
a calculated sinking rate of 36.0 fps. which agrees fairly well with the 
tunnel data. 
Using the estimated weight in sea water of 40.4 lbs (BuOrd sketch 
No. 239308) for the 6-in. Projector Charge, one finds terminal sinking 
• 
velocities of 32.6 fps for the flat nose projectile and 34. 3 fps with the 
artned Ex 102 nose fuse. Ave:rage drag coefficients of 0.280 with flat 
nose an-d 0.185 with armed nose fuse are reported by the Alden Hydraulic 
Laboratory.(4) Sinking rates calculq.tedlrom this data were 27.2 and 
33.4 fps, respectively. 
-3-
--- ~------
K 
Fig. l - Two -inch diameter models of the 6 -in. Projector Charge, Ex l (top) 
and the 5 -in. A. S. Projectile, Ex 30 (bottom) 
. 80 
. 70 
.60 
.50 
0 
.40 (_) 
1--: 
z 
w 
0 
.30 Li: 
u... 
w 
0 
(.) 
<!) 
<t 
a:: 
.20 Cl 
. I 0 
~5- IN. A.S . PROJECTILE 
~ 
"' _f '"' 
""' 
NO FUSE 
-cD 
' '"' «; 
_£:) FUSE 
v I'-"-' w-----
---
-
-~ f> 
!;;;, r::. 
~ ~ ~ ~ t- NO FUSE ,.,. (;:, -.A. ~ ~ 
~ - - FUSE 
6-IN. PROJECTOR CHARG E 
2 3 4 5 6 7 8 9 10 20 
REYNOLDS NUMBER X 10- 6 
Fig. 2 - Drag coefficient vs. Reynolds number for models of 
5-in. A. S. Projectile and 6-in. Projector Charge 
30 
-4-
APPE~DIX 
Increased Drag Due to Shroud and Fin Sing 
During the drag runs with both the 5-in. A. S. Projectile and the 
6-in. Projector Charge, it was noted that at certain velocities a clear 
singing note could be heard coming from the model tail. Notations were 
made on the data and it was later observed that in every case where sing-
ing was noted, except for the higher freq~encies, there was a small but 
distinct increase in drag. Singing of this type has been observed before 
in the High Speed Water Tunnel on hydrofoils. As reported by Gongwer,(S) 
these notes caused by the Karman vortex street would fade as the velocity 
of the water was increased, disappear, and then reappear as a note of 
higher frequency. Two points of increased drag corresponding to this fin 
singing can be seen on the curves for the 5 -in.A. S. Projectile (Fig. 2) at 
Reynolds numbers of 3.5 and 7.0 x 106 . 
REFERENCES 
1. Kermeen, R. W. ,"Resistance Tests on a Series of Flat Nose Bodies, 
the 6-in. Projector Charge, the 5-in. A. S. Projectile", 
Hydrodynamics Laboratory, California Institute of Technology, 
Memorandum Report No. EM 12. 2, Aug. 1951. 
2. Kermeen, R. W., "Pitching Moment Balance for the High Speed Water 
Tunnel", Memorandum Report No. EM 12.4, April 15, 1952. 
3. "Underwater Performance of 1-1/4-in. Model of the 5-in. A. S. Pro-
jectile, Ex 30," Alden Hydraulic Laboratory Report No. 21, 
Feb. 1951. 
4. "Water Entry and Underwater Performance Characteristics of the 
1-1/4-in. Model of the 6-in. Projector Charge, Ex 1," 
Alden Hydraulic Laboratory Report No. 23, April 1951. 
5. Gangwer, <;. P . • , "A Study of Vanes Singing in Water". Aerojet Engi-
neering Corporation, Sept. 1951. 
Copy No. 
1 
:z. 
3-4 
5-7 
8-12 
13-15 
16 
17-18 
19-ZO 
21-22 
23-24 
25-26 
27 
:Z.8 
29 
30 
31-32 
33-34 
35-44 
45 
46 
47 
48 
49 
50 
DISTRIBUTION LIST FOR NOrd 961Z 
California Institute of Technology 
Pasadena, California 
Name and Address 
Chief, Bureau of Ordnance, Navy Department, Washington 
Z.5, D. C., Attention: Code Re6a 
Code Re3d 
Code Ad3 
Chief, Bureau of Aeronautics, Navy Department, 
Washington 25, D. C., Attention: Code De3 
Chief, Bureau of Ships, Navy Department, ··washington 
25, D. C. 
Chief of the Office of Naval Research, Navy Department 
Washington Z5, DP C., Attention: Code 438 
Office of Naval Research, Los Angeles Branch, 
1030 East Green Street, Pasadena, California 
Director, David Taylor Model Basin, Washington 7, D. C. 
Commanding Officer, NaVal Torpedo Station, Newport, R, : 
Commander, Naval Ordnanee Test Station, Inyokern, 
China Lake, California 
Commander, Naval Ordnance Test Stationr Pasadena 
Annex, 3202 East Foothill Blvd., Pasadena 8, California 
Commander, Naval Ordnance Laboratory, White Oak 
Silver Spring 19, Maryland 
Director, Stevens Institute of Technology, 711 Hudson 
Street, Hobo}ten, N. J.; Via: Bureau of Aeronautics Rep,.. 
resentative, c/o Bendix Aviation Corp., Eclipse -Pioneer 
Division, Teterboro, New Jersey 
Director, Ordnance Research Laboratory, Penn. State 
College, State College, Pennsylvania 
Alden Hydraulic Laboratory, Worcester Polytechnic 
Institute, Worcester, Mass. Via: Inspet;tor of Naval 
Materiel, Summer Street, Boston 10, Mass. 
Inspector of Naval Materiel, Development Contract 
Section, 1206 South Santee Street, Los Angeles, Calif. 
Superintendent, U.S. Navy Postgraduate School, 
Annapolis, Maryland 
Director, U.S. Naval Elect:ronics Laboratory, Point 
Lama, San Diego; California 
British Joint Services Mission, Navy Staff: Via: Chief• 
Bureau of Ordnance, Navy Department, Washington 25, 
D. C., Attention: Code AdS 
Executive Secretary, Research and Development Board 
National Defense Building, Washington, D. C. 
Dr. Lindvall, Chairman, Division of Engineering, Cali-
fornia Institute of Technology 
Dr. E. Bromberg, Office of Naval Research, Mechanics 
Branch 
Underwater Ordnance Dept., Naval Ordnance T~tst Sta., 
Thomp son Laboratory, Grand Ave., Pasadena, Calif. 
At tn: Code P80 
Attn : Code P 8001 
Commander, Submarine Development Group TWO, 
c/o Fleet Post Office, New York, N. Y. 


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Resistance Tests on the 5-in. A. S. Projectile and the 6-in. Projector Charge

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