Interim 14. IX Supplementary Notes_16. "Exte n sive measurements of the mean velocity, wall pressure and wall shear stress fields were Meade in a three-dimensional pressure-driven turbulent boundary layer created by a cylinder with trailing edge placed normal to a flat plate floor.The direct force wall shear stress measurements were made with a unique, floating element direct force sensing shear mater that responded to both the magnitude and direction of the local wall shear stress.These data were used to test the ability of ten near-wall similarity models proposed in the literature to describe the near-wall velocity field for the measured flow under a wiee range of skewing conditions and a variety of pressure gradient and wall shear vector orientations. S. Performing Organization Report Number. Insect if perfotming organization wishes to assign this number.9. Performing Organization Name and Mailing Address. Give name, street, city, state, and zip code. List no more than two levels of an organizational hierarchy. Display the name of the organization exactly as it should appear in Government indexes such as Government Reports Index (GRI).10. Project/ Took/Work Unit Number. Use the project, task and work unit numbers under which the report was prepared.11. Contract/Grant Number. Insert contract or grant number under which report was prepared.12. Sponsoring Agency Name and Mailing Address. Include zip code. C:-e main sponsors.13. Since the majority of documents are multidisciplinary in nature, the primary Field/Group assignment(s) will be the specific discipline, area of human endeavor, or type of physical object. The application(s) will be cross-referenced with secondary Field/Group assignments that will follow the primary posting(s).18. Distribution Statement. Denote public relessabilicy, for example " Release unlimited", or limitation for reasons other than security. Cite any availability to the public, other than NTIS, with address, order number and price, if known. These three-dimensional velocity field, wall pressure field, and wall shear field results were used to test the ability of ten near-wall similarity models proposed in the literature for three-dimensional turbulent boundary layers to describe the near-wall velocity field. Six of these ten models are scalar, treating some form of an equivalent velocity component. Three of the remaining four more complex models are twocomponent vector models and the last is a scalar model which recognizes the vector nature of the near-wall flow by way of a developed velocity.All. of the ten models tested find their origin, directly or indirectly, in an equilibrium boundary layer hy pothesis using a mixing length. there is the problem of fixing a lower y + limit below which data could not be used.If one were to use these three more complex models in a computational scheme replacing the no slip wall boundary condition at the wall with a match to a similarity model near the wall, then for the flows described above, such a match should be made in a range of about 50 < y ...

Unique, simultaneous direct measurements of the magnitude and direction of the local wall shear stress in a pressure-driven three-dimensional turbulent boundary layer are presented. The flow is also described with an oil streak wall flow pattern, a map of the wall shear stress-wall pressure gradient orientations, a comparison of the wall shear stress directions relative to the directions of the nearest wall velocity as measured with a typical, small boundary layer directionally sensitive claw probe, as well as limiting wall streamline directions from the oil streak patterns, and a comparison of the freestream streamlines and the wall flow streamlines. A review of corrections for direct force sensing shear meters for two-dimensional flows is presented with a brief discussion of their applicability to three-dimensional devices.

Eleven near-wall similarity models for three-dimensional turbulent boundary layers which have been identified in the literature are reviewed. Each model summary includes a brief review of its derivation, discusses limitations in the derivation, estimates the applicable y+ range, and compares differences among the models. This review of three-dimensional similarity models was developed as part of a larger study which tests the validity of ten of these different models by comparison with experimental data which includes the direct and simultaneous measurement of the local wall shear stress direction and magnitude in a three-dimensional turbulent flow. A direct force measurement of local wall shear stress is necessary to test the local wall shear-shear velocity relationship, τ0 = ρq*2, generally assumed in three-dimensional flows. This review is necessary to acquaint the reader with the similarities and differences among the models tested in companion papers since differences among some of the models are significant, particularly in the coordinate systems of the vector models.