Finding the Bed Shear Stress Using the Logarithmic Law at Channel Roughness Transitions

Flow through transition of bed roughness occurs in many situations in highway transportation including culverts, bridge abutments, and roadways in the floodplain, where the bed materials can change abruptly from one type to another. A sudden change in bed roughness also occurs frequently in the laboratory when soil erosion and scour is studied using a sediment recess in an open-channel flume. In all the above, the bed shear stress is a fundamental flow parameter that must be determined accurately. A research project is proposed to investigate the use of logarithmic law (log law) for finding bed shear stress near a sudden change in bed roughness. Velocity field measurements will be obtained using a Particle Image Velocimetry (PIV) system. The measured data will be used to determine the distribution of bed shear stress by control volume analysis using the linear momentum equation to determine whether the log law can be applied to a developing boundary layer downstream of a bed roughness transition and develop procedures to reduce the measurement uncertainty of the method.

• Record URL:
  • https://www.ctips.org/projects/details.php?id=663

Language

• English

Project

• Status: Active
• Funding: $123,582.00
• Contract Numbers:

  69A3552348308

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Managing Organizations:

  Center for Transformative Infrastructure Preservation and Sustainability

  North Dakota State University
  Fargo, North Dakota  United States  58108-6050
• Project Managers:

  Tolliver, Denver

• Performing Organizations:

  South Dakota State University

  Civil & Environmental Engineering
  Brookings, SD  United States 
• Principal Investigators:

  Ting, Francis

• Start Date: 20251216
• Expected Completion Date: 20271215
• Actual Completion Date: 0
• USDOT Program: University Transportation Centers Program
• Source Data: CTIPS-066

Subject/Index Terms

• TRT Terms: Boundary layer flow; Research projects; Roughness; Shear stress; Streambeds; Velocimeters
• Subject Areas: Bridges and other structures; Design; Highways; Hydraulics and Hydrology; Research;

Filing Info

• Accession Number: 01980901
• Record Type: Research project
• Source Agency: Center for Transformative Infrastructure Preservation and Sustainability
• Contract Numbers: 69A3552348308
• Files: UTC, RIP
• Created Date: Feb 23 2026 1:58PM