322 P. Mandel 
had to be based on visual observations through the viewing ports in the sides of the tank. — 
It might be noted, however, that in spite of the limitations imposed by both the crudity of 
the measurements and inadvertent leakage of the model, the tests provided important guid- 
ance to the design of the Aluminaut. 
Model Drag 
Results showing the relationship between ascent velocity and the net buoyancy and 
drag for the model conditions and configurations tabulated in Table 3 are shown in Fig. 9. 
100 
90 
Points plotted indicate experiment results as follows: 
NARROW KEELS, SMALL STERN FINS, 6/10-I2 TESTS 
80 NARROW KEELS, LARGE STERN FINS, 7/ 27-29 TESTS 
WIDE KEELS, SMALL STERN FINS, 6/10-l2 TESTS 
WIDE KEELS, LARGE STERN FINS, 7/27-29TESTS 
LINES [INDICATE COMPUTED RESULTS 
70 
Pounds 
oO 
(o) 
Drag or Net Bouyancy, 
aS oa 
(@) (e) 
30 
20 
O 1.0 2.0 3.0 4.0 5.0 6.0 7.0 
Ascent Velocity, Ft./Sec. 
Fig. 9. Model vertical-drag data, experimental and computed 
