Case: Debris Tracking in Turbulent Flows

Dr. Nils Goseberg from the University of Hannover, Germany, and currently a Visiting Professor at the University of Ottawa, Canada, who, together with his collaborator Prof. Ioan Nistor from the Department of Civil Engineering and their graduate student, Jacob Stolle, have created a “smart” debris tracking system using Quuppa technology. The project is supported by Marie Curie International Outgoing Fellowship funded by the European Union Research Agency.

The goal of the research is to track marine debris that are set loose when hit by a tsunami or by flood. The team is trying to understand how debris behave and what kind of forces are at play when they hit buildings and other structures. The data from this research can be used to build stronger buildings that can survive such incidences, especially in tsunami-prone areas, such as Japan, US and Canadian West Coast, Chile and even in the Mediterranean countries. The research team has submitted their first paper, in which they collected data with the help of Quuppa’s technology. This first case focused on modelling how containers located within a harbor area would spread and get carried inland, if hit by a strong wave.

Challenges

The challenge that Dr. Goseberg and his collaborators from the University of Ottawa had, was how to get reliable and accurate positioning data form the model containers. The containers were at times temporarily submerged under water or otherwise not directly visible. The system should also provide enough relevant data points to determine the containers’ position. A camera system alone would not work, as the containers might not be visible, and also as there would be myriad of visual information that would have to be analyzed further to get the position data. The initial testing tank was 4 x 5 meters large – however, bigger tests were scheduled to be implemented. The system should give very accurate positioning data and be scalable to bigger areas, as well.

Solution

Dr. Goseberg and his collaborators used a combination of Quuppa solution, together with a motion sensor and two cameras, to analyze how the model containers behaved. This implementation was able to give them accurate and reliable positioning data throughout the experiment. IMG_1010“For the determination of their spatial position, the “smart” debris system uses a real-time locating system (RTLS). This technology was selected for its most important performance indicators: accuracy, range, sampling frequency, and cost. Following thorough product review of these indicators, the technology provided by Quuppa Oy (www.quuppa.com) was selected.” In the first data collection phase, the team used only four standard Quuppa LD-6L Locators. They set up a system to cover the tank and started collecting data. Even with just four Locators, the data had good accuracy. exp24_result_debrisPositionWith the help of the Quuppa system, the data they gathered was not only accurate in terms of the model containers’ position but also had a good sampling rate. The Quuppa Tags sent out the position of each model container 50 times per second, so that the team was able to analyze their movements in detail. Also, if the containers were submerged, the system was able to reconnect fast once they reappeared at the surface. “Quuppa system was easy to deploy and calibrate in only one afternoon”, says Dr. Nils Goseberg

Future

In the near future Dr. Goseberg and his collaborators will submit the next paper as well as conduct the next round of experiments at the University of Ottawa. In the long run, the research will give new insights into impact of extreme forces on buildings and structures, and hopefully these insights will save lives and keep buildings intact when facing tsunamis.


Read more: Updates on the project’s facebook page Project homepage Presentation: “Flood-Induced Debris Dynamics over a Horizontal Apron” (pdf)