With more than 35,000 individual members and 90 corporate members, AIAA is the world’s largest technical society dedicated to the global aerospace profession. Created in 1963 by the merger of the two great aerospace societies of the day, the American Rocket Society (founded in 1930 as the American Interplanetary Society), and the Institute of the Aerospace Sciences (established in 1933 as the Institute of the Aeronautical Sciences), AIAA carries forth a proud tradition of more than 75 years of aerospace leadership.

Lieuwen was also recently appointed by Secretary Steven Chu of the Department of Energy as a member the National Petroleum Council.  Lieuwen also serves as the Executive Director of the GT Strategic Energy Institute (SEI). The National Petroleum Council (NPC), a federally chartered and privately funded advisory committee. The purpose of the NPC is solely to advise, inform and make recommendations to the Secretary of Energy with respect to any matter relating to oil and natural gas, or to the oil and gas industries submitted to it or approved by the Secretary. The NPC does not concern itself with trade practices, nor does it engage in any of the usual trade association activities.

The Council also has members with interests outside of oil or gas operations, including representatives from academic, financial, research, Native American, and public interest organizations and institutions.

Lieuwen's research interests lie in the areas of acoustics, fluid mechanics, combustion, and signal processing. He is responsible for teaching several courses in the areas of fluid mechanics, aeroacoustics and combustion. His research activities involve both theoretical and experimental work in combustion, flame-acoustic wave interactions, combustion noise, and development of ultrasonic diagnostic techniques.