Future flight vehicles will be required to emit lower and potentially different types of gases and particles in order to be more environmentally responsible. Particles emitted from jet turbines serve as cloud nuclei, and changes in their microphysical properties will impact upper level cloud formation, including contrails, which represents the major impact of aviation emissions on atmospheric radiation balance (climate change). Investigations into the impacts of current and future aviation emissions must determine any changes in the degree to which emissions affect contrail formation, cirrus cloud formation, and their evolution over time. The SBIR project seeks to develop an instrument suitable for both ground-based emission measurements as well as in-flight, low-pressure measurements of the ice forming properties of particles emitted from jet engines, building on existing continuous flow diffusion chamber approaches. The new instrument, the Counter for Ice Nucleated in Contrails Homogeneously and Heterogeneously (CINCH2), will measure ice formation by exposing engine emission particles to a region of controlled temperature and water vapor supersaturation and measuring any ice crystals that form in those conditions. The CINCH2 approach is well suited for both ground-based and airborne-based measurements because it will be fast, relatively compact, and capable of reproducing the entire range of atmospheric conditions important for studying ice nucleation processes. Phase II work will develop and test major subsystems for sample conditioning, refrigeration, and ice crystal detection, and combine these into a portable prototype instrument. Our overall goal is to produce the first commercial instrument capable of measuring ice formation in contrail emissions, as well as be suitable for studying ice formation on naturally-existing airborne particles in cirrus conditions more broadly.
Applications include NASA's Advanced Air Vehicles Program, which has the goal of enabling new aircraft to "fly...cleaner, quieter, and more efficiently", which in turn requires minimization of aviation impacts on the environment. It will serve as a powerful new tool for characterizing emissions on the ground at NASA facilities, such as the Advanced Subsonic Combustion Rig at NASA Glenn Research Center. The technology is also relevant to NASA's Earth Science Research Program and aviation emission focused missions such as ACCESS and ACCESS II.
Non-NASA applications include university-led research focused on understanding ice cloud formation and evolution, as well as government-led airborne research focused on similar topics, both domestically and internationally. Applications include both aircraft-based work, such as that performed by NOAA, NSF, DOE and DLR, and ground-based research in labs and other ground-based combustion facilities.