Unclassified 



Security Classification 



DOCUMENT CONTROL DATA - R&D 



(Security clBssitiCBtion ot title, body of abstract and indexing annotation must be entered when the overall report is classified) 



1 ORIGINATING ACTIVITY (Corporate author) 



David Taylor Model Basin 



2s. REPORT SECURI TY CLASSIFICATION 



Unclassified 



Zb GROUP 



3. REPORT TITLE 



The Hydrogen-Bubble, Flow-Visualization Technique 



4 DESCRIPTIVE NOTES (Type of report and inclusive dates) 



Final 



5. AUTHORfS; fl,as( name, first name, initial) 



Mattingly, George E . 



6- REPO RT DATE 



February 1966 



TOTAL NO. OP PAGES 



50 



76. NO. OF REFS 

 11 



8a. CONTRACT OR GRANT NO. 



fa. PROJECT NO. S-R009-0101 



Task 0103 



9a. ORIGINATOR'S REPORT NUMBERfS; 



nfaers that may be assigned 



None 



10. AVAILABILITY/LIMITATION NOTICES 



Qualified requesters may obtain copies of this report from DDC. 



11. SUPPLEMENTARY NOTES 



None 



12. SPONSORING MILITARY ACTIVITY 



Bureau of Ships 



13 ^355CRKKK 



SUMMARY 



The hydrogen-bubble visualization technique has been adapted to the 12- inch 

 variable -pressure water tunnel of the David Taylor Model Basin. An outline of 

 this adaption and the operation of the technique are described. 



Photographic techniques and analyses applied to the resulting films are dis- 

 cussed. Sources of error are delineated, particularly with regard to the decep- 

 tive streakline patterns that can be formed and especially the results of exceed- 

 ing the velocity limitation imposed by the shedding phenomena taking place behind 

 the platinum wires . Errors caused by compression and/or stretching of bubble 

 lines along their length are discussed, and procedures are given for recognizing 

 this type of error. In addition, cathode-wire configurations are described by 

 which both longitudinal and transverse velocity profiles can be obtained in 

 steady or unsteady water flows . 



Various cathode-wire configurations are described through which qualitative 

 aspects of the flow about bodies as stagnation and separation point motions are 

 depicted. 



DD /.A°re. 1473 



Unclassified 



Security Classification 



