1 / 14

Hydraulics of Engineered Log Jams

Hydraulics of Engineered Log Jams. Tessa Hanson. Background. ( fs.fed.us ). . Research Question. Fish Behavior with respect to Engineered L og Jams (ELJs). . ( freshwatersillustrated.org ). . My Research. Drag force Calculate drag c oefficient Shear s tress distribution

arista
Download Presentation

Hydraulics of Engineered Log Jams

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hydraulics of Engineered Log Jams Tessa Hanson

  2. Background (fs.fed.us). Tessa Hanson, Oregon State University

  3. Research Question • Fish Behavior with respect to Engineered Log Jams (ELJs). (freshwatersillustrated.org). Tessa Hanson, Oregon State University

  4. My Research • Drag force • Calculate drag coefficient • Shear stress distribution • Calculate shear stress • Map distribution over control volume Tessa Hanson, Oregon State University

  5. Relevance • Impact of log jams on hydraulic processes (shear stress, drag, etc.) • Hydraulic processes  Geomorphic complexity (pools, riffles, etc.) • Both geomorphic and hydraulic complexity affect habitat for aquatic species. Tessa Hanson, Oregon State University

  6. Methods • Data Collection • Velocity: SonTekMicroADV (Acoustic Doppler Velocimeter) Devices • Topography: Total Station Surveying (SonTek, 2008). Tessa Hanson, Oregon State University

  7. Methods • Control Volume • Defined by influence of ELJ, which corresponded to extent of velocity measurements. Tessa Hanson, Oregon State University

  8. Methods • Drag Coefficient • Momentum extraction technique, where sum of forces equal to momentum flows Tessa Hanson, Oregon State University

  9. Methods • Force balance (equation) Balance in y-direction Balance in x-direction (Manners et al. 2006). Tessa Hanson, Oregon State University

  10. Methods • Shear Stress Distribution • Create matrices of velocity data to analyze in Matlab. • Given: • Solve for and map in Matlab. Tessa Hanson, Oregon State University

  11. Results/Conclusions • Drag Coefficient • High compared to that found in literature • Possibility that control volume does not capture entire eddy at downstream. • Shear Stress Distribution • Matrices were not completed with all of necessary values. Tessa Hanson, Oregon State University

  12. Recommendations • Drag Coefficient • Extend control volume. • Recalculate shear using integral form. • Shear Stress Distribution • Finish matrices. • Interpolate over 10 cm gaps to obtain finer spacing. • Solve for and map in Matlab. Tessa Hanson, Oregon State University

  13. References • Manners, Rebecca B., M. W. Doyle, and M. J. Small. "Structure and Hydraulics of Natural Woody Debris Jams." Water Resources Research 43 (2006). • SonTek. “15-MHz MicroADV expanded description.” YSI incorporate (2008). Tessa Hanson, Oregon State University

  14. Questions? • Thank-you to: • DesiréeTullos • Cara Walter • Chad Higgins • Will L’Hommedieu • Julia Jones • Peggy Lee • Amanda Reinholtz Tessa Hanson, Oregon State University

More Related