Training Flume Helps Engineers Get Their Hands Wet – And Keep Their Roads Dry

How much water can a culvert pass? Which pavement inlets work best? Does a liner change a pipe’s capacity? What problems can arise when there’s just too much water? Federal Highway Administration (FHWA) and Ayres Associates engineers have designed a training tool to help transportation engineers answer these and many more questions about highway drainage design: a tabletop flume.

The flume is a small open channel (6 inches wide and 5 feet long) with a pump to cycle 30 gallons of water through the flume. What makes this contraption unique – even setting it apart from many flumes that university labs have – are its small-scale models of hydraulic structures typically used in highway drainage applications. Hand-crafted models of weirs, orifices, storm drain inlets, culvert inlets, culvert barrels, pipe liners, and energy dissipaters are placed in the flume, allowing students to get a hands-on experience with how water reacts under certain conditions.

Since 1995 Ayres engineers have been using the flume to teach highway drainage design to transportation departments nationwide through FHWA’s National Highway Institute (NHI) training courses, many of which are taught by Ayres experts. The flume always gets rave reviews in students’ evaluations.

The flume provides critical hands-on learning that isn’t possible through typical classroom instruction. The class is divided into groups called “design squads,” and they are assigned experiments. The results are then discussed and shared with the whole class.

The contraption is one-of-a-kind; it is not mass producible. It was designed to be portable, which is a good thing since its travels would easily qualify for any frequent flier program. Ayres experts teach an average of 12 to 15 courses each year using the flume, and they are now on the third-generation flume because it tends to get beaten up in shipment. It takes about an hour to set up at a training venue.

To see the flume in action, check out the video above showing a demonstration by Ayres engineer John Hunt, one of many Ayres staff certified to teach NHI drainage design courses. An explanation and listing of all FHWA National Highway Institute training courses is described on NHI’s website. In particular, note the “Introduction to Highway Hydraulics” course (NHI 135065), and the “Culvert Design” course (NHI 135056) that have been using the flume to help engineers better understand highway drainage for over 20 years.

Interested in learning more? Contact John.