| NSF Org: |
AGS Division of Atmospheric and Geospace Sciences |
| Recipient: |
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| Initial Amendment Date: | March 17, 2020 |
| Latest Amendment Date: | March 17, 2020 |
| Award Number: | 2023920 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Sylvia Edgerton
sedgerto@nsf.gov (703)292-8522 AGS Division of Atmospheric and Geospace Sciences GEO Directorate for Geosciences |
| Start Date: | April 1, 2020 |
| End Date: | September 30, 2023 (Estimated) |
| Total Intended Award Amount: | $29,988.00 |
| Total Awarded Amount to Date: | $29,988.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
8 CLARKSON AVE POTSDAM NY US 13676-1401 (315)268-6475 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
8 Clarkson Avenue Potsdam NY US 13676-1401 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | Atmospheric Chemistry |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
This EAGER project supports the development of a new inlet for the NSF/NCAR G-V aircraft that will enhance the ability of scientists to measure ambient ions, condensable vapors, and short-lived reactive species in the atmosphere. These types of compounds typically exist in the atmosphere at very low levels, are highly reactive, and are typically lost upon first contact with a surface. Therefore, sampling becomes a critical factor in their measurement. The new inlet will become an important community resource for air sampling from the G-V aircraft. Society will benefit from the improved tools for predicting the sinks of greenhouse gases, the sources of aerosols, and the impact of these on air quality and climate.
This effort includes the early stages of the design, construction, and assessment based on computational fluid dynamics simulations, and the Federal Aviation Authority certification of a laminar flow inlet that is pre-requisite for quantitative sampling of condensable vapors and ambient ions; and this effort also explores the feasibility for autonomous startup of an inertia navigation system using differential GPS for inlet-free remote sensing detection of radical species in the open atmosphere. Currently, certified inlets on the G-V aircraft use turbulent air flow regimes that are subject to wall losses, and suitable for the sampling of longer lived species. The autonomous remote-sensing and laminar inlet design will enable the sampling of a multitude of organic and inorganic radical and short lived species not possible with the currently available inlet designs. The new inlet will provide the potential to fill gaps in our understanding of oxidative capacity, and those condensable vapors that add to the early growth of nanoparticles. This research includes the participation of two graduate students and a postdoctoral scholar.
Although this EAGER proposal is exploratory and is a high-risk, high-reward effort, the extensive experience of the participating scientists and their existing analytical capabilities reduce both the risk and the required investment.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Gas-phase aircraft sampling is critical for trace gas atmospheric measurements. Commonly it is assumed that gas can be sampled at 100% efficiency using any gas inlet design. In this study we used computational fluid dynamics (CFD) simulations to first study an existing as inlet, called the laminar gas inlet. We modeled flow through the different stages of the gas inlet, accounting for exact inlet geometry, gas-ion generation, and the sampling tube characteristics. As the flow regime for aircraft sampling encompasses turbulence and compressibility, the accuracy of turbulent model predictions needs to be evaluated with experiments. Here, we conducted high-speed wind-tunnel experiments to measure turbulence in the inlet as a function of freestream velocity under speeds as high as 180 m/s and measured the resultant impact on gas-transport efficiency through the inlet and downstream sampling system. Our experimental data shows that the combination of appropriate Reynolds-Averaged Navier Stokes (RANS) modeling with gas-species transport modeling, allows for accurate gas transport modeling under aircraft conditions. The most efficient gas-transport operation requires us to design the inlet to bring flow at near isokinetic condition into each sub-sample stage and transport the flow at moderate Reynolds numbers (~ 2000 to 4000) to balance laminar and turbulent diffusional loss. Accounting for the calculated efficiencies greatly improves our ability to quantify atmospheric composition of trace gases which is important from both a climate and human health perspective.
Last Modified: 02/08/2025
Modified by: Suresh Dhaniyala
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