Category: Technology

The Flow of the River: What 2D Hydraulic Modeling Can Teach us about Movement

GIF image of 2D hydraulic modeling showing water under a bridge

Imagine trying to measure water in a beaker or in a measuring cup; it is stagnant and easy to follow the line of meniscus to see if it’s a ½ cup or 3/4. Then imagine measuring water in a river in order to build safer bridges; it tumbles over rocks, it changes speed, it experiences different water levels throughout a season.

Believe it or not, water movement is one of the most difficult phenomenon to solve. Yes, you can apply mathematics or numerical methods to solve complicated differential equations, but there are always some unknowns about turbulent flows (class 4 rapids) where general assumptions are made.

Rivers require intricate numerical models for river-type engineering problems, and I have been accepted to present on these intricate models at this years biennial National Hydraulic Engineering Conference (NHEC) in Columbus, Ohio. The Conference spans a week from 8/27 to 8/31, and I will be presenting on Friday, August 31st.

Per the NHEC website (https://www.ohio.edu/engineering/nhec/), the conference is themed “Advancing Hydraulic Engineering through Innovation and Resilient Design,” and will address the challenges that transportation agencies face to construct, maintain, sustain, and improve hydraulic structures in the physical, natural, social, and economic environments of today and tomorrow. At this conference, I will be presenting on Two-Dimensional (2D) Hydraulic Modeling with Tidal Boundary Conditions.

Modelers typically use computer software packages where you input topography, flows, roughness parameters, and hydraulic structures. The software package uses the input to solve mathematical equations. It seems simple enough, but a modeler needs to have a conceptual understanding of numerical methods and know the limitations of the software package being used.

Whenever you hear the term “3D,” you think of an object in a space that has 3-dimensions, right? Similarly, water moves within a 3-dimensional space, where there is a z-component (up, down), y-component (left, right), and x-component (back, forth). What if I were to tell you that the movement of water in the z-direction (up, down) is not considered?

What would that mean? Well, what that means is that mathematically, we are simplifying a very complicated problem:  we are restricting movement of water to flow/move in 2D, 2-directions (x and y) and that is what 2D hydraulics is all about. Similarly, a one-dimensional (1D) hydraulic model is defined when the y-direction is neglected and water is confined to moving in the x-direction.

2D hydraulic modeling is not that new and has been available in an academia setting since the 80s. But in recent years, tools to develop 2D models have been readily available to engineers. A 2D model can’t be developed for every problem that we tackle, but it allows us to accurately represent actual real world conditions, make less assumptions and judgment calls, and communicate and show visualizations of flow movement to stake holders.

How has Hoyle, Tanner and the Aviation Industry Changed over the Last 45 Years?

jets with colored streams

In 1903 the first manned flight lasted 12 seconds and went for 120 feet. Today, unmanned aerial vehicles, more commonly known as drones, can stay airborne for up to 30 minutes and have a maximum range of 34 miles. August 19th is National Aviation Day, and it has us reflecting on how far the aviation industry has come since that first flight in 1903 and how our company has transformed along with it.

OPENING THE DOORS to the SKYWAYS

Forty-five years ago in 1973, Doug Hoyle and John Tanner formed Hoyle, Tanner. They began their firm providing only aviation and environmental engineering services. Today, Hoyle, Tanner has expanded into multiple engineering disciplines, with over 100 employees. One of our firm’s early major milestones in our aviation engineering service capabilities occurred in 1986 when Hoyle, Tanner was selected to prepare the Master Plan for Ellington Field in Houston, Texas. Ellington Field needed to maintain its role as a base for military and NASA operations, but at the same time become an airport for the public. Careful planning and diligent efforts were made to please those involved. In the end, the Master Plan was completed on schedule and rolled out to the public in 1987; the City had a new airport. Commercial, corporate, military and private interests were better served, and there was an expectation for an up-tick in regional economic activity. Hoyle, Tanner’s Airport Master Plan for this airport was ultimately used as a guide to implement a comprehensive program to plan and upgrade the former military base to meet its new civilian status.

CHANGING WITH TECH

Historically, aeronautics has evolved alongside technology. For approximately the first 20 years of the company’s history, our aviation design engineers and draftsman worked together to illustrate airfield improvement project designs on polyester drafting film known as Mylar. This was a labor-intensive process that could be compounded when considering alternative design scenarios. In the early 1990s, Hoyle, Tanner began using engineering design and drafting software. The incorporation of Autodesk Land Desktop allowed for increased accuracy, a more efficient design process, and the development of a product that can be more easily used to engage the public.

TERROR IN THE SKYS

A major shift in the aviation industry occurred following the 2001 terror attacks. Prior to the attacks, you could follow your loved ones to the gate to see them off on their journey. Today all those good-byes happen before security check points. Two months after the attacks, on November 19th, Congress federalized airport security by passing the Aviation and Transportation Security Act. This security measure and others, such as body scans and shoe removal, were an effort to protect the safety of the traveling public. On a more practical note, cell phone and laptop charging stations have become the norm in every terminal to accommodate the lengthy wait time before, and between flights.

A NEW GENERATION OF EXPLORERS

With the significant decline in pilots and the FAA expansion of regulations, the industry is seeing a drop in commercial airline pilots. The drop is not exclusive to pilots. A recent study by Boeing, projects the need for 790,000 new aviation pilots for the next 20 years. This equals to roughly 108 new pilots every day for the next 20 years. Aviation is not exclusive to pilots. Other careers include: engineering and mechanics, airport operations, and aircraft manufacturing. With several hundred thousand pilots and mechanics retiring over the next decade, the need for the new enthusiasts grows. For the past five years, Hoyle, Tanner has partnered each summer with Aviation Career Education (ACE) Camps to expose the next generation of aviation enthusiasts to the aviation field.

THANKFUL

In the 45 years that Hoyle, Tanner has successfully navigated the civil engineering world, we are able to reflect on our roots in appreciation. So much of our success has stemmed from those early days mapping the skyways, and we owe much of our aeronautical achievements to that one milestone: The Master Plan for Ellington Field in Houston.

Drones: Enhancing Safety & Expanding the Aviation Community

Flying Drone

Small Unmanned Aerial Systems (sUAS), or as they are more commonly known as, drones, are changing inspection and construction methods and expanding the aviation community. Drones are the fastest growing segment of aviation. Currently, they are being used by public safety officials, realtors, farmers, engineers and of course by aviation hobbyists across the country. Depending on your perspective, drones are an emerging aerial solution or an impending aerial disaster just waiting to happen.

A major concern of the FAA regulators are the hazards of drones and manned aircraft in the same airspace. On December 12, 2017, Barrie Barber from Cox Newspapers published “FAA: Drones more deadly than birds.” In the article, Barber writes the “FAA has guidelines for building aircraft to withstand bird strikes of a certain weight, but tougher requirements do not exist specifically for drone collisions.” While it might seem obvious that a drone could do some damage, the impact damage of a bird and drone of similar weight are significantly different.

“The research found heavier, stiffer components, such as a drone motor, battery or a camera, could cause more structural damage to an aircraft than birds of the same weight and size,” said Kiran D’Souza, an Ohio State University assistant professor of mechanical and aerospace engineering.

While pilots have reported many drone sightings to the FAA, the FAA reports only one incident in the United States of a drone striking a Military Black Hawk helicopter in October 2017. In fact, the Unmanned Aircraft Safety Team (UAST) Drone Sightings Working Group released a new report on the Federal Aviation Administration’s (FAA) 3,714 drone sightings reports collected by flight crews, air traffic controllers and citizens from November 2015 to March 2017. The report found that only a small percentage of drone reports pose a safety risk, while the vast majority are simply sightings.

Despite growing pains employing drones, many industries and public agencies are adding them as tools and developing workflows to effectively employ them. Stamford Connecticut police Sgt. Andrew Gallagher did an interview for the Fairfield Citizen and explained how his police department has used drones to document and analyze accident scenes, conduct searches and track suspects. Fire Departments are now using drones with infrared cameras to quickly view fire scenes from different angles to best direct the crew response.

“I have stood on more fire trucks than most firemen looking for an overhead shot. We are always looking for something to stand on,” Gallagher says in the article. Drones provide different aerial shots that can give intelligence about where a person or accident could be – in real time, without putting lives in danger.

In addition to first responder use and Amazon’s idea to deliver packages via the airways, drones have provided opportunities in the professional planning and engineering field.

Evan McDougal, Airport Planning Manager with Hoyle, Tanner & Associates, Inc., is an FAA-certified manned aircraft pilot as well as an FAA Section 107 Remote Pilot. McDougal says that drones are an inexpensive data collection solution when airports have tree obstructions that have grown into the runway approach surfaces. These obstructions can limit the ability of pilots to use instrument approaches at night and in some cases the obstructions cause the FAA to increase the cloud ceiling or visibility requirements or limit how low a pilot can descend on approach to a runway. Many runway ends in Maine are not available at night due to known tree obstructions.

McDougal believes drones could be part of the solution.

Drones can quickly capture highly accurate aerial imagery that can be analyzed using photogrammetry software to identify the boundaries of tree canopy penetrating the imaginary (but very real) instrument or visual approach surface. An example of the typical results can be seen in this effort. https://www.dropbox.com/s/iw4vabrcszm5w1s/B21_17%20End%20P4D%20Ani.mp4?dl=0

How it works: while following an autonomous flight plan the drone takes hundreds of georeferenced high definition photos. Photogrammetry software accurately stitches these photos together by matching thousands of key points within adjacent photos. This creates a full orthomosaic of the entire surveyed area and produces a very accurate three-dimensional model or point cloud that can be measured and examined thereby allowing engineers and airport owners to see exactly where runway obstructions exist.

This is but one use for a drone at airports. The technology is evolving very quickly and is limited only by our imagination.

Capturing Data in a New Era

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This season Hoyle, Tanner employees are finding all sorts of ways to get out into the field. An essential aid to us in our field work is a GPS data collector. Employees from all departments have been utilizing the GPS data collector to collect centimeter grade accuracy GPS data in multiple states across New England. The variety of jobs the GPS is being used for includes tasks such as collecting utility pole locations in Massachusetts, flagging wetlands in New Hampshire, performing quality assurance checks of bridge superstructure construction in Vermont, utility asset management for multiple municipalities across New Hampshire and much, much more.

The strength of the GPS data collector is not only in its ability to collect highly accurate, horizontal and vertical data, but also in its extreme ease of use. Horizontal data can be collected in the World Geodetic System 1984 (standard latitude and longitude) or any of the state plane coordinate systems, and the vertical data is collected in the North American Vertical Datum of 1988. The GPS is powered by an android operating system, and requires no GIS or survey experience to learn how to use. The device also streams real time kinematic (RTK) corrected global navigation satellite system (GNSS) positions.  These real time corrections allow the user to see coordinates of shots as they are taken which also eliminates the need for special software to post-process the data back in the office.  The GPS data collector is capable of outputting both GIS shapefiles and ASCII text files, and it is also capable of inputting GIS shapefiles that can be viewed as a layer while collecting data in the field.

The GPS data collector is a powerful tool that has greatly improved the quality of field visits for the Hoyle, Tanner staff.  The ability to obtain highly-accurate GPS data with the click of a button while on project sites is changing the way we accomplish tasks, and we’re doing it in a more efficient manner.