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ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #345921

Research Project: Improved Practices to Conserve Air Quality, Maintain Animal Productivity, and Enhance Use of Manure and Soil Nutrients of Cattle Production Systems for the Southern Great Plains

Location: Livestock Nutrient Management Research

Title: Pilot-scale concept of real-time wind speed-matching wind tunnel for measurements of gaseous emissions

Author
item MAURER, DEVIN - Iowa State University
item KOZIEL, JACEK - Iowa State University
item BRUNING, KELSEY - Iowa State University
item Parker, David

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2017
Publication Date: 7/17/2017
Citation: Maurer, D., Koziel, J.A., Bruning, K., Parker, D.B. 2017. Pilot-scale concept of real-time wind speed-matching wind tunnel for measurements of gaseous emissions. ASABE Annual International Meeting. Paper No. 1701656. July 16-19, 2017, Spokane, Washington. https://doi: 10.13031/aim.201701656

Interpretive Summary:

Technical Abstract: Comprehensive control of odors, hydrogen sulfide (H2S), ammonia (NH3) and odorous volatile organic compound (VOC) emissions associated with animal production is a critical need. Current methods utilizing wind tunnels and flux chambers for measurements of gaseous emissions from area sources such as feedlots, lagoons, pastures and cropland are often criticized for potential bias. The bias is due to the temporal isolation of the emitting surface, affecting the air velocity and temperature at the surface, forcing controlled surface-to-gas-phase mass transfer, and therefore, affecting emission measurements. That bias can limit the applicability of these methods to relative and comparative measurements. In this research, a new approach is proposed to minimize these biases with a specially constructed wind tunnel. Pilot-scale experiments were conducted to evaluate an instrumented wind tunnel capable of reproducing ambient air and soil-air mass transfer conditions in real time. Matching the inside of the wind tunnel with ambient conditions is based on simultaneous measurements of wind velocity near the emitting surface, and real-time adjustment of a wind tunnel fan to minimize velocity differences. The wind tunnel’s wind speed matching parameters were first optimized in regards to wind velocity sampling rate and wind velocity match criteria. The optimum wind tunnel operating parameters chosen resulted in a 25 percent absolute difference in the wind velocities generated in the wind tunnel compared to the outside wind velocities. An instrumented wind tunnel capable of reproducing ambient air and soil-air mass transfer conditions in real time could be a promising tool for measuring NH3 and VOC emissions from land-applied livestock wastes.