P ww~^ 



Figure lb - Electrolytic Tank Fitted with Cross 

 Beams and Carriage 



Figure la - Electrolytic Tank Fitted with Pantograph 



Figure 1 - General Views of the Electrolytic Tank 



pantograph or on a small carriage mounted on cross beams which slide on a pair of rails fas- 

 tened to the long sides of the tank. 



The tank lining adopted for the TMB electrolytic tank was cast of a wax compound (30 

 percent aristo and 70 percent beeswax), and the surfaces were made smooth and plane by hand 

 scraping. This type of lining was adopted after considerable trouble was encountered with a 

 glass lining. The glass plates were difficult to seal and they cracked easily. It was impor- 

 tant to avoid leaks as it was impossible to operate with a low resistance between the electro- 

 lyte and the metal frame. The presence of beeswax in the wax compound makes the lining 

 more pliable and less apt to crack with changes in temperature. Moreover, cracks in the wax 

 are easily repaired. 



The velocity and pressure distributions about two-dimensional bodies are investigated 

 in the TMB tank with the use of Analogy A by placing dielectric cylindrical bodies at the 

 center of the tank or by mounting half of the cylinder on one of the vertical tank walls. Simi- 

 larly, in the study of three-dimensional bodies of revolution, a quarter body is mounted on one 

 of the vertical walls and the water level is brought exactly to the axis of the body. In both 

 cases, the electric field is explored by probing the surface of the electrolyte in contact with 

 the body.* 



The dielectric models used with Analogy A have been machined out of the same hard 

 wax compound that is used for ship models at the Taylor Model Basin, ^ and they are sprayed 

 with Krylon, a waterproofing plastic compound which is hydrophobic, to eliminate the meniscus 



It is hoped that a technique can be developed for determining the pressure distribution about three-dimensional 

 bodies with only one or two planes of symmetry, such as a ship model. The field about such bodies will be ex- 

 plored beneath the surface with a slender insulated probe with only the tip exposed. 



