A New Generalized Cross-Flow Momentum Integral Method for Three-Dimensional Ship Boundary Layers.
Abstract:
A new cross-flow model for a three-dimensional momentum integral turbulent boundary layer calculation method has been developed. This cross-flow model utilizes two parameters and is capable of representing the reversal s-shaped cross-flow profiles that do occur in ship boundary layers. The new method uses only an extra algebraic equation for determining the extra cross-flow parameter. The basic momentum integral equations used by the method are the streamwise and cross-flow momentum equations and the entrainment equation. The method has been programmed for calculating ship boundary layers. Certain higher order geometric effects have been included. Test calculations for the experimental boundary layer data of the SSPA-Model 720 have been made. The results are very promising. Good agreement with experimental data is obtained over that portion of the hull where viscous-inviscid interactions do not occur. Near the stern the predictions are qualitatively correct. The s-shaped, cross-flow profiles are predicted near the stern but they are some-what inaccurate. The addition of viscous-inviscid interaction capabilities to the calculation should greatly improve the predictions of the boundary layer near the stern. Author