Experimental measurements of methane plume transport in a turbulent atmospheric wind tunnel*

Methane is a potent greenhouse gas with more than 20 times the global warming potential of carbon dioxide. The US Environmental Protection Agency (US EPA) has recently proposed new guidelines to reduce methane emissions from the oil and natural gas industry. A major obstacle to reducing anthropogenic methane emissions is determining the source location. In this project experimental measurements are taken in a turbulent atmospheric boundary layer wind tunnel to determine the turbulent dispersive methane plume growth one to 20 meters downwind of the leak source. Aeris Technologies sensors are used to determine the plume concentration profile in turbulent background flow speeds of 1 m/s to 6 m/s. The intermittency of the experimental data shows evidence of methane transport due to vortical fissures within the uniform momentum zone of the turbulent wall-bounded flow. Combining a statistical model for vortical fissures with the traditional Gaussian plume growth model is expected to give a good characterization of scalar transport in turbulent environments.