Transient Boundary Layer Disturbance Growth and Bypass Transition Due to Realistic Roughness and Continued Study of Transition Over Riblets
Abstract
In this two part study we worked on surface texturing for turbulent boundary layer control and on a collaborative effort with Ed White to understand how surface roughness induces boundary layer transition. Streamwise textures including triangular riblets and fins were explored in an effort to inhibit the spanwise spreading of turbulent spo1/wedge disturbances. Appreciable care has been taken in examining the meaning of spreading angle. We have concentrated on the mechanisms of lateral spreading of the regions of turbulence. Since we use DNS in our work, we have been able to utilize a range of tricks, unavailable in a physical experiment, in an attempt to tease out the causes of lateral spreading of spots. In a parallel effort, we have concentrated on matching results from previous DNS done by Rizetta and Visbal and experiments done by White for flow over an array of tiny cylindrical perturbations. In an effort to understand the differences we have conducted some simple flow visualization and LDA surveys in the UT water channel and have examined in detail the vorticity dynamics about the perturbation. We have also demonstrated agreement between our DNS of lateral flow over distributed roughness patches and the TAMU experiments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 19, 2011
- Accession Number
- ADA563957
Entities
People
- David B. Goldstein
Organizations
- University of Texas at Austin