ABSTRACT 



Results of velocity measurements in the boundary layer of 

 USS TIMMERMAN (EAG 152) are presented in this report. Measurements of 

 velocities in the throat of the condenser scoop and the pressure drops across 

 the condenser are also given. A generalized form of Prandtl's equation for 

 the growth of the turbulent boundary layer on a flat plate is derived for use in 

 estimating the boundary-layer thickness at large Reynolds numbers. 



INTRODUCTION 



The design of USS TIMMERMAN (EAG 152) (formerly DD828) included many innovations 

 in naval and marine engineering. The ship was conceived as a mobile marine experimental 

 facility where new design features could be evaluated. Provision was also made for installing 

 instrumentation and scheduling tests that would provide information applicable to naval archi- 

 tecture and marine engineering, in general. The Bureau of Ships requested^ that the 

 David Taylor Model Basin design instrumentation for and conduct a flow survey in the vicinity 

 of the condenser scoop and the overboard discharge of the forward main circulating system for 

 a range of ship speeds. Measurements of fluid velocity in the throat of the condenser scoop, 

 pressures, and pressure drops in the condenser and main circulating system were also requested. 



These tests had the following objectives: 



1. Boundary-layer measurements in the undisturbed flow ahead of the condenser scoop and 

 overboard discharge would provide valuable hydrodynamic data on the nature (i.e., thickness 

 and velocity distribution) of a ship's .ndary layer. 



2. Measurements of flow direction and velocity in the immediate vicinity of the condenser 

 scoop and overboard discharge would demonstrate the effect (or lack of effect) of these hull 

 openings on the flow around the vessel. 



3. The measurements in the throat of the condenser scoop and of pressures and pressure 

 drops in the condenser and main circulating system, could be used along with objectives 1 

 and 2, to simulate conditions for model tests of condenser circulating system. Such data 

 would also be useful in correlating the results of model tests with full-scale performance. 



The tests were conducted during November 1955 in the operating area off Key 'Vest, 

 Florida. 



References are listed on page 18. 



