SHEAR STRESS AND PRESSURE DISTRIBUTION 
ON A SURFACE SHIP MODEL : 
THEORY AND EXPERIMENT 
IT. T. Huang and C,H. von Kerczek 
Naval Ship Research and Development Center 
Bethesda, Maryland, U.S.A. 
ABSTRACT 
This paper presents the results of an experimental 
and theoretical investigation of the distribution of 
shear stress and pressure on BRIAN BORU, a 20- 
foot model of a Series 60, Block 60, surface ship. 
Boundary layer calculations were carried out using 
the Cumpsty-Head-Smith momentum integral me- 
thod under the small crossflow assumption; the po- 
tential flow was obtained from slender body theory 
for zero Froude number. Surface shear stressand 
pressure distribution were measured at sixty points 
on the hull ; the magnitude and direction of shear 
stress were determined from high-aspect ratio hot 
films and Preston tubes, Additional data on total 
resistance, sinkage, trim, and wave profiles on the 
hull are also presented. 
The experimental and theoretical results are com- 
pared for a range of Froude numbers(0.2<Fn<0.35) 
The present boundary layer computationis adequate 
for the ship model tested ( moderate block coeffi- 
cient) if the potential flow around the ship is accu- 
rately prescribed. The sinkage and trim, and wave 
profiles along the hull predicted by thin ship theo 
ry are not in good agreement with the measured 
values. 
1963 
