Software Tools for the Changing Environment

Three Dimensional Computational Fluid Dynamics Analysis to Determine Flow Capacity of an ADA Compliant Street Drain Grate

  • Steven Lottes (Argonne National Lab)


Analysts at Argonne National Laboratory’s Transportation Research and Analysis Computing Center (TRACC) used three dimensional computational fluid dynamics (CFD) to determine the flow capacity of a street drain grate that is compliant with the Americans with Disabilities Act (ADA). When urban roads are resurfaced with concurrent repair and/or replacement of sections of curb and sidewalks, ADA compliant pedestrian ramps at crosswalks may be required. Storm drains are often located near crosswalks, and may be in the crosswalk. In that case, an ADA compliant replacement grate would be required. The openings in ADA compliant grates are smaller than traditional grates and their hydraulic capacity is less. In order to maintain total street drainage capacity when ADA compliant grates are used the hydraulic capacity of the new design must be determined. CFD analysis was used as an alternative to flume testing of an ADA compliant grate. Traditionally flume testing of grate capacity is done, however, flume conditions do not correspond directly to street conditions, and therefore procedures were needed to calculate capacities under full scale street design conditions. CFD analysis of flow through grates was done at full scale using a section of the street containing the drain. Calculation of the flow intercepted by the grate was carried out for parametric matrix of street longitudinal and cross slopes and curb water depths. Cases with different gutter and street cross slopes were also included.

The analysis used the volume of fluid model (VOF), which is used in the analysis of free surface flows. When water passes through the grate, the free surface breaks up and becomes highly irregular. Initial testing with the method was done before the start of the study to verify that the VOF method would preserve an accurate mass balance under these conditions. Pressure boundary conditions were used for the water flow exiting the domain at street level and into the catch basin. Use of these conditions allowed the fraction of water diverted into the grate to be determined. The presentation will cover need for the study at Minnesota DOT, the CFD model development, and results of the study, including flow visualization.

How to Cite:

Lottes, S., (2014) “Three Dimensional Computational Fluid Dynamics Analysis to Determine Flow Capacity of an ADA Compliant Street Drain Grate”, National Hydraulic Engineering Conference 2014 1(2014).

Rights: Copyright © 2014 the presenters

Publisher Notes

  • Panel moderated by Dan Ghere, FHWA.
  • About the Presenters: Dr. Steven Lottes is an Argonne theorist specializing in Computational Fluid Dynamics (CFD) of multiphase and reacting flows. He is currently the CFD simulation, modeling, and analysis lead at Argonne’s Transportation Research and Analysis Computing Center. He plans and coordinates CFD research on transportation applications, provides technical support to the center’s user community, develops training materials, and conducts training and technology transfer events to advance the use of CFD in solving aerodynamic and hydraulic problems that arise in maintaining and building transportation infrastructure. Dr. Lottes has extensive experience in the modeling and analysis of a variety of multi-phase, reacting, and other complex flow systems. He is the author/co-author of 4 copyrighted CFD software codes including Argonne’s Glass Furnace Model that received an R&D100 Award in 2004. Dr. Lottes received a Master’s degree from Purdue University in Computer Science and a Master’s and PhD degree in Mechanical Engineering from the University of Illinois at Chicago.



Published on
23 Aug 2014
Peer Reviewed