Engineering topics

Adrian, Ronald J.

Publications and source records attributed to Adrian, Ronald J..

3 records

NASA NTRS1997

Instantaneous Structure of Turbulent Separated Boundary Layers

This report describes the final results of the project, which are reported in the reference in Appendix A. This reference contains the technical details, and will constitute the main body of the report. The paper in Appendix A was first presented at the 8th International Symposium on Applications of Laser Techniques to Fluid Mechanics, July, 1996. This paper was one of 30 papers selected from more than 200 papers presented at the symposium for publication in a book by Springer-Verlag. It will become available during 1997.

Adrian, Ronald J.↗

NASA NTRS1990

Linking correlations and structure - Stochastic estimation and conditional averaging

The principles and applications of stochastic estimation are reviewed and the results of various investigations as they pertain to the structure of shear flow turbulence are presented. These results support a picture in which hairpin vortices and/or vortex rings dominate in the outer layer, whereas structures elongated in the streamwise direction and possessing vorticity in the streamwise direction dominate the wall layer. They may result from vortices moving along the wall, or the vortices may result from the interaction of the streamwise streaks with the wall and with themselves.

Adrian, Ronald J.↗

NASA NTRS1988

Stochastic estimation of organized turbulent structure - Homogeneous shear flow

A generalization of the conditional-eddy concept is proposed in which the conditional event specifies the local kinematic state in terms of the velocity and the deformation. Results are presented for stochastically estimated conditional eddies given the local kinematics. The equation governing the probability density function of a kinematic state has been derived for constant-property incompressible flow, providing a link between coherent flow structures corresponding to the conditional eddies and the modelling of turbulent transport. The primary contributions to the second-quadrant and fourth-quadrant Reynolds-stress events in homogeneous shear flow are shown to come from flow induced through the 'legs' and close to the 'heads' of upright and inverted 'hairpins', respectively.

Adrian, Ronald J.↗