210 G. J. Wennagel 
——— ane 
Nemioean tint ARC LEADING EDGE RADIUS=0.0.15 IN. 
FORWARD CRUISE FOIL SECTION 
R=RADIUS OF UPPER SURFACE CONTOUR 
LOCATION C IN. T HIN. R IN. 
OUTBOARD END 11.940 0.811 177.733 
DIHEDRAL BREAK 8.394 . 0.578 124 .688 
CIRCULAR ARC LEADING EDGE RADIUS =0.015 IN. 
FORWARD DIAGONAL FOIL SECTION 
R=RADIUS OF UPPER SURFACE CONTOUR 
LOCATION T IN. 
OUTBOARD TIP 0.72 
INBOARD END 1.20 
PARABOLA 
TRAILING EDGE RADIUS = 0.062 IN. 
LOWER FORWARD STRUT SECTION 
PERCENT CHORD T IN. 
60. | 0.375 
81.5 0.375 
92.7 0.260 
Fig. 4. Cross sections of the elements of a forward hydrofoil assembly 
edge. Over the lower regions of this element, a tapered afterbody is added to the basic 
section. At low speeds, prior to cavity formation, this afterbody reduces the drag which 
would exist for the basic section. At higher speeds, after cavity formation, the afterbody 
is essentially unwetted but still contributes to section strength and stiffness. The diago- 
nal foil elements, which are wetted only during low-speed operation, employ a subcavitating 
cross section with a vented base. This section employs a flat bottom, a circular-are upper 
Ai 
