Outlet diffusers to increase culvert capacity.
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields



Publication Date Range:


Document Data


Document Type:






Clear All

Query Builder

Query box

Clear All

For additional assistance using the Custom Query please check out our Help Page


Outlet diffusers to increase culvert capacity.

Filetype[PDF-4.39 MB]

  • English

  • Details:

    • Alternative Title:
      Technical report 14-17 : outlet diffusers to increase culvert capacity.
    • Publication/ Report Number:
    • Resource Type:
    • Abstract:
      Aging infrastructure and changing weather patterns present the need to increase the capacity of existing highway culverts. This research approaches this challenge through the use of diffuser outlet systems to increase pipe capacity and reduce outlet losses. A summary of relevant literature, Computational Fluid Dynamics (CFD) modelling studies, and test results of scale model diffusers provide the background information necessary to understand the design requirements of diffusers and how they function. Properly designed inlets, diffuser outlets, and outlet weirs are all important components of an effective diffuser system. Incorporating these requirements, a prototype diffuser was designed, installed and tested on an existing undersized pipe in Thorndike, Maine. The diffuser was monitored through the fall, winter and spring of 2015-2016. A method for calculating flows was developed using a drawdown technique involving the ponding and releasing of water through the diffuser system. This data was used to quantify the performance of the diffuser, and to compare it to traditional straight pipes as well as diffuser systems discussed in the literature. The Thorndike field study demonstrated that a diffuser system could be inexpensively fabricated, easily installed, and successfully used to consistently increase pipe capacity. To the best of our knowledge, this is the first successful field test of a diffuser in a highway application.
    • Format:
    • Main Document Checksum:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at rosap.ntl.bts.gov

    Version 3.26