ABSTRACT 



The design and development of an electrolytic tank is described and a dis- 

 cussion is given of some of the difficulties encountered in putting the tank into 

 operation. The techniques developed for finding the velocity and pressure dis- 

 tributions about cylindrical bodies and about three- dimensional bodies of revo- 

 lution are described, and some results obtained for bodies with known velocity 

 and pressure distributions are presented. 



INTRODUCTION 



An electrolytic tank has been constructed and put into operation at the David Taylor 

 Model Basin as part of a project to study the hydrodynamic flow about torpedoes and other 

 bodies.^ In this tank it is possible to survey velocity distributions of the potential flow about 

 two-dimensional bodies and three-dimensional bodies of revolution with an accuracy compara- 

 ble to that obtained by direct measurement in the towing basin or water tunnel. The method may 

 eventually be extended to study more general types of flow on three-dimensional bodies, pres- 

 sure distributions on a ship model, pressure distributions induced on a nearby wall by a moving 

 body, etc. 



Electrolytic tanks have been built at many laboratories both in this country and abroad. 

 Two-dimensional tanks were built at the National Physical Laboratory in England before 

 1930,^'^ and during the next twenty years L. Malavard and his colleagues perfected techniques 

 and extended applications to many problems of aerodynamics. The method has also been ex- 

 tended to determine the flow about three-dimensional bodies, particularly to bodies of revolution, 

 flow through conduits, etc. 



This paper describes the electrolytic tank which has been built at the Taylor Model 

 Basin for two- and three-dimensional studies, reports the techniques developed for obtaining 

 pressure distributions, and discusses the difficulties which have been encountered. 



THEORETICAL CONSIDERATIONS 



The steady irrotational flow of an incompressible inviscid fluid may be represented by 

 a potential function ^S (x, y, z) which is a solution of the Laplace equation (see standard 

 texts in hydrodynamics, e.g., Lamb. ) 



^^=—L+ — ^+_JL=o [1] 



dx^ dy^ dz^ 



References are listed on page 28. 



