147 



viscid stern flow interation on axisymmetric bodies. 

 The measured static pressure distributions on the 

 body and across the entire thick boundary layer and 

 wake were predicted by the displacement body method 

 to an accuracy within one percent of dynamic pres- 

 sure. Theoretical predictions of the measured 

 axial and radial velocity profiles outside the dis- 

 placement surface were improved significantly when 

 the variations of the static pressure and radial 

 velocity of the displacement body were incorporated 

 into the computation. 



Neither the measured values of eddy viscosity 

 nor mixing length were found to be proportional to 

 the local displacement thickness or the local 

 boundary-layer thickness of the thick axisymmetric 

 boundary layer. As the boundary layer thickens 

 rapidly at the stern, the turbulence characteristics 

 in the outer region remain quite similar but the 

 turbulence reduces its intensity and becomes more 

 uniformly distributed in the inner region. The 

 measured mixing length of the thick axisymmetric 

 stern boundary layer was found to be proportional 

 to the square root of the area of the turbulent 

 annulus between the body surface and the edge of 

 boundary layer. This simple similarity hypothesis 

 can be incorporated into existing differential 

 boundary-layer computation methods. 



ACKNOWLE DGMENT 



The work reported herein was funded under the 

 David W. Taylor Naval Ship RSD Center's Independent 

 Research Program, Program Element Number 61152N, 

 Project Number ZR 000 01. 



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APPENDIX 



The raw data and derived results of the present 

 experiments are tabulated in the following so that 

 they can be used independently by other investi- 

 gators . Table 3 shows the measured pressure and 

 shear stress coefficients on Afterbodies 1 and 2. 

 Tables 4 and 5 provide the measured static pres- 

 sure coefficients across the stern boundary layers 

 and near wakes of Afterbodies 1 and 2, respectively. 

 Tables 6 and 7 contain the values of measured mean 

 axial and radial velocities, three components of 

 turbulence fluctuations, and Reynolds stresses 

 across the boundary layer and near wake of After- 

 bodies 1 and 2, respectively. The experimentally 

 derived data on eddy viscosity, mixing length, 

 planar and axisymmetric displacement thickness, and 

 boundary layer thickness are also given. 



