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APPROVED FOR PUBLIC RELEASE; 

 DISTRIBUTION IS UNLIMITED. 



a PERFORMING ORGANIZATION REPORT NUMBER(S) 



DTNSRDC-85/086 



5 MONITORING ORGANIZATION REPORT NUMBER(S) 



6a NAME OF PERFORMING ORGANIZATION 



David Taylor Naval Ship 

 Research and Development Center 



6b OFFICE SYMBOL 

 (If applicable) 



Code I8U3 



7a NAME OF MONITORING ORGANIZATION 



6c ADDRESS (City. State, and ZIP Code) 



Bethesda, MD 2008U-5000 



7b. ADDRESS (Ofy. State, and ZIP Code) 



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6II52N 



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ZROII4O2OI 



" 'cAL^iuLAfldN'o^^M-ffMNSIONAL NONLINEAR FLUID FLOW RESULTING FROM LARGE-AMPLITUDE 

 FORCED HEAVE MOTION OF A U-SHAPED CYLINDER IN A FREE SURFACE 



WORK UNIT 



WWoS§ 



nw U78IPS 



12 Ph'RSONAL AUTHOR(S) 

 Telcite. John G. 



I3a rvPf OF REPORT 



Final 



13b TIME COVERED 

 FROM TO 



4 DA.TE OF REPORT (Year, Month, Day) 

 1985, December 



15 PAGE COUNT 

 51 



'6 SUPPLEMENTARY NOTATION 



COSATI CODES 



'2xr 



-uir 



18 SUBJECT TERMS (Continue on reverse if necessary and identify by block number) 



Free Surface Effects, Heaving Cylinder, Perturbation 

 Theory, Ship Motions, Ship Hydrodynamics, Water Waves 



ABSTRACT (Continue on reverse if necessary and identify by block number) 



Progress in developing a tool to compute large amplitude ship motions is reported. 

 In particular, a method to calculate transient two-dimensional potential flow about a 

 body moving in a free surface is described. The flow problem is formulated as an initial- 

 boundary value problem in which the velocity potential along the free surface and the 

 positions of the moving boundaries are sought as solutions of a coupled system of 

 differential equations. An implicit finite-difference method is used to advance the 

 solution of the coupled system of equations in time. The auxiliary problem of computing 

 the velocity potential inside the fluid region is solved by a method which is based on 

 boundary- fitted coordinates and is directly extensible to three-dimensional flows. 

 Results from calculating the potential flow about a body in forced heave motion are 

 presented. The hydrodynamic force on the body has been obtained and compared with the 

 hydrodynamic force predicted from second-order perturbation theory. 



^0 Distribution /AVAILABILITY of abstract 



ElijritLASSlFIED/UNLIMlTED D SAME AS RPT 



D DTIC USERS 



21 ABSTRACT SECURITY CLASSIFICATION 



UNCLASSIFIED 



-i -JA'yiE OF RESPONSIBLE INDIVIDUAL 



John G. Telste 



22b TELEPHONE f/nc/ude Area Code) 

 ( 2 02) 227-1929 



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Code I8H3 



DO FORM 1473, 81 MAR 



83 APR edition may he usod until exhausted 

 All other editions are obsolete 



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