ABSTRACT 



Static pressure distributions, mean velocity profiles, 

 distributions of turbulence intensities, and Reynolds 

 stresses, spatial correlation coefficients, and the Taylor 

 microscale of turbulence were measured across the stern 

 boundary layer of an axisymmetric body with an inflected 

 stern. A theoretical and numerical iteration scheme, 

 which uses the boundary layer and open wake displacement 

 body, is found to model satisfactorily the viscid- inviscid 

 interaction between the thick stern boundary layer and the 

 external potential flow. The measured values of turbulence 

 intensity, eddy viscosity, and mixing-length parameters in 

 the stern region are found to be much smaller than those of 

 a thin boundary layer. An approximate similarity character- 

 istic for the thick axisymmetric stern boundary layer is 

 obtained when the measured mixing-length parameters, the 

 measured correlation length scales, and the measured Taylor 

 microscales are normalized by the square root of the 

 boundary-layer cross-sectional area instead of the local 

 boundary layer thickness. When this simple similarity 

 hypothesis for the mixing length and the displacement body 

 is incorporated into the McDonnell Douglas Corp., Cebeci- 

 Smith differential boundary-layer method, modified to 

 consider the displacement body and wake, the theory pre- 

 dicts very well the measured distributions of the mean 

 velocity throughout the entire stern boundary layer. The 

 computation method developed earlier was found to predict 

 well the boundary layer on convex sterns and is now found 

 to apply equally well to the flow on inflected sterns. 



ADMINISTRATIVE INFORMATION 

 The work described in this report was funded under the David W. Taylor 

 Naval Ship Research and Development Center's Independent Research Program, 

 Program Element 61152N, Project Number ZR 000 01, and Work Unit 1552-103. 



INTRODUCTION 

 This report presents measurements of the turbulent boundary layer 

 characteristics in the thick stern boundary layer of an axisjmmietric body 

 with an extremely full inflected stern. These measurements include the 

 distributions of pressure coefficient and shear stress on the body, static 

 pressure distribution across the stern boundary layer, mean velocity pro- 

 files, turbulence intensities, Reynolds stresses, eddy viscosity, mixing 



