Katlyn represents FluxLab in the United Kingdom and Belgium

I travelled to the United Kingdom to help with fieldwork coordinated by Dave Lowry’s research group at Royal Holloway University of London (RHUL) in November 2017. This trip was part of a knowledge exchange between our lab and Dave Lowry (with whom our lab has previously partnered) that involved a member of each respective group joining each other’s methane measurement campaigns. We completed two days of extensive mobile measurement surveys in several different areas of the UK, all of which offered more varied scenery than that of my most recent Canadian fieldwork in Lloydminster, AB (a plus)!

IMG_2175Day one was spent sampling in a coal mine and around several landfills in Wales. Collected data was used for a student’s senior project, and we were able to have full site-access to the open cut anthracite mine. While at the mine, we drove down in the pit in a Land Rover to continuously measure methane using a portable LGR LRanalyzer. We also periodically took bag samples in areas of high methane concentrations for isotopic analysis, which was done back in Lowry’s lab after the campaigns. The pit is 150 – 200 metres deep and the coal seams, which we were able to see up close, range from a few centimetres to over a metre in thickness. The mine plans to close in 2018, with remediation immediately following. The rest of the day involved scoping out smelly landfills, which was not quite as exciting as touring around a mine in a Land Rover, but still interesting none the less.

Day two consisted of continuous measurement surveys along the North Sea coast, where our main target was large onshore natural gas terminals and compressor stations. We did not have site access to these facilities, so we measured around the perimeters of them and tried to get downwind of any observed plumes.We also took several bag samples during these surveys for isotopic analysis, which made the space in the car very limited by the end of the day!

While we were checking out the facilities, we travelled through several small towns and communities, which were beautiful. COUNTRY


The next two days were spent in the lab back at RHUL analyzing the bag samples thatRUHL were collected atsites of interest. Lowry’s lab was equipped with a high-precision, automated mass spectrometer, which was really cool to see in action. While waiting for samples to run, I also explored around the university, which was the most beautiful campus I have ever seen (sorry StFX)!

During this trip, I also represented the Flux Lab at the Industrial Methane Measurement Conference (IMMC), ANTWERPwhich was held in Antwerp, Belgium. The 2-day conference consisted of several interesting presentations on current methane measurement technologies and challenges in Europe and abroad.

This trip was my first time outside North America, and I was able to take in 3 countries in a short time; I think it goes without saying that this was a field experience I will never forget!

Many thanks to Dave Risk and Dave Lowry for the amazing opportunity.

Using CFD to Accurately Measure Wind Speed from a Cyclist

Screen Shot 2018-04-25 at 11.11.17 AMThe main focus of our research is on the aerodynamics of cycling. We began working alongside Alphamantis Technologies in Montreal (recently acquired by Garmin) on a project to measure wind from bicycles.

Why would one want to measure wind speeds on a bicycle? By accurately measuring wind in real-time, the computation of real-time CdA (Drag coefficient * frontal area) of a cyclist becomes feasible.  Doing these computations within a bike computer would give cyclists real time information from which they could optimize their position – to minimize their drag, and maximize speed. In this project, we explored the effect of wind probe location on measured wind speed, and derived correction factors for various positions.Screen Shot 2018-04-25 at 11.16.49 AM

Using ANSYS Fluent CFD (Computational Fluid Dynamics) software, we modelled the wind flow over a full-scale cyclist. We built a bicycle and an aero-positioned rider, and then explored the wind flow patterns surrounding the cyclist under a range of different conditions. Wind speeds between 5m/s and 20m/s were chosen to simulate a biker’s velocities as well as yaw angles ranging from 5 degrees to 35 to replicate outdoor conditions. We recorded the effect of each factor on the measured wind speeds from five different locations chosen as potential peto-tube (miniature anemometer) locations. We computed a correction factor for each probe location.

Our research has shown that wind speed can in fact be measured with reliability from a carefully placed peto-tube, with the correct calibration offsets.

Cycling has always been a leader amongst sports in technological evolution. This research will eventually help cyclists around the world slide through the wind faster!

A special thanks to Nayani Jensen, Tara Hanlon, Dave Risk, the Alphamantis team and ANSYS for their contributions and guidance.  Also check out Tara’s related blog post on using CFD to properly calibrate truck-based anemometer measurements.ANSYSlogo

How does anemometer placement affect measurement accuracy of vehicle-mounted anemometers?

Wind measurements are an important part of gas leak plume detection, which we do by truck.  I’ve been working with ANSYS Fluent software and anemometer measurements from the mobile survey trucks to investigate vehicle-based wind measurements. My MSc. project is a field- simulation study comparing experimental field measurements with CFD simulations, to explain how anemometer placement and the vehicle’s external flow field,affect measurement accuracy of vehicle-mounted anemometers.

DSC_0061Along with Nayani Jensen, I conducted field tests in Saskatchewan to explore the effects of anemometer placement, vehicle speed, and wind yaw angle on measured wind speed and direction. We tested five different anemometer positions on the truck, and used stationary anemometers to compare against the mobile measurements.

TruckGeomWe found that our truck-mounted anemometer over-estimated wind speeds, particularly for low mounting positions, high vehicle speeds, and large side winds (> 40% of vehicle speed).  This indicated that corrections are needed for vehicle speed and wind yaw angle. Screen Shot 2018-04-25 at 10.58.56 AM

Screen Shot 2018-04-19 at 11.01.41 AMBack at the lab, we used a Toyota Tacoma CAD model to create Computational Fluid Dynamic (CFD) simulations using ANSYS Fluent, to study the flow field around our truck as a function of speed, yaw angle, and anemometer placements.  We replicated the conditions under which field tests were conducted, but ANSYS Fluent also allowed us to explore a much wider range of conditions.

Our simulations agreed very closely with field measurements.  We are working with the results from the CFD, and field components of this study, to improve our truck-based wind measurements by calibrating anemometer measurements for anemometer placement, vehicle speed, and wind yaw angle.

Measuring wind from trucks isn’t much different than measuring wind from bikes (see this blog post) or from other vessels in motion like boats. Modeling wind fields with CFD has proven a good substitute for field work in these applications.