Propulsion and Combustion
Introduction
August 1, 2003
Improving Propulsion systems, such as air-breathing and rocket engines is a constant challenge for future engineers and scientists. Propulsion systems combine complex fluid dynamics with energy conversion processes, such as combustion. The research being carried out by Georgia Tech's propulsion and combustion group focuses on the interplay between these processes, not only in propulsion systems but also in a wide variety of other energy conversion devices. Georgia Tech faculty have earned international reputations in the areas of solid rocket propellants, combustion instability, pulse combustion, combustion control, diagnostic and sensor technology, and computational modeling. The group is composed of five professors, four research engineers, and about 25 graduate students and post-doctoral fellows.
Since propulsion devices are complex systems their study requires an interdisciplinary approach. The propulsion and combustion group collaborates with experts in other disciplines, such as research on turbomachinery with the aerodynamics faculty. Collaborative efforts are also in place with members of other Georgia Tech schools, such as Electrical and Computer Engineering and Mechanical Engineering through activities such as the Multidisciplinary University Research Initiative on Intelligent Turbine Engines (MITE). Research support comes from numerous sources, including industry and government.
The propulsion and combustion (PC) group conducts basic and applied research in a wide variety of areas. Specific projects include active control of unsteady phenomena in turbine engine combustors and liquid-fueled rocket engines; microgravity combustion; development of nonintrusive, optical-based diagnostic and sensor techniques; measurement and control of soot and particulate emissions; underwater explosions; combustion mechanisms of composite solid propellants, focusing on modern energetic ingredients used in solid rockets and missiles; pulse combustion; and efficient modeling of realistic, turbulent, single- or two-phase combustion systems using large eddy simulations, in which this laboratory is a world leader.
The propulsion and combustion group maintains facilities in the same complex that houses most of the School of Aerospace Engineering, and in a separate 8000 square-foot building. The experimental facilities are numerous and include: various combustors and flow tunnels that can be supplied with high pressure (up to 55 bar), and high temperature (up to 800 K) air for simulating the inflow to combustion chambers of air-breathing engines; high pressure (> 140 bar) solid rocket propellant combustion chambers; and a large water tank for studying underwater explosions. Modern measurement devices, including optical diagnostic techniques, are available and routinely employed. These include laser Doppler velocimetry (LDV) and phase Doppler anemometry (PDA) systems; high-speed (>1 kHz) imaging systems based on digital cameras, which can also be combined with high-repetition rate metal vapor lasers for real-time evaluation of transient phenomena; tunable, high energy pulsed laser systems that are coupled to high-resolution, sensitive digital cameras for nonintrusive planar imaging measurements.
Numerous computerized data acquisition systems are employed for real-time data reduction and analysis. Computational facilities include supercomputers and workstations networked locally and through the internet. The primary computing facility consists of three Silicon Graphics Power Challenge 1 and an Origin 2000, for a total of 32CPUs, 7 GB of memory and over 70 GB of disk storage. The CPUs can be used individually or in a parallel mode direct-connected by a high-speed switched network. In addition, there are a large number of user workstations. Additional systems available at Georgia Tech include a 22-processor SGI system, an 8-processor IBM SP-2 and a 2-CPU Cray YMP/EL.
The School of Aerospace Engineering at Georgia Tech maintains world-class research and academic programs in propulsion and combustion. Through its expertise in combustion modeling, solid propellants, unsteady combustion, and advanced optical-based measurements, the School will continue to advance in these fields. Improvements in accurate and efficient computational modeling tools like LES will improve the ability of researchers to probe the behavior of complex combustion systems, and of engineers to design propulsion devices that must meet ever increasing standards. Georgia Tech’s unique program in solid propellants will provide rocket designers the understanding needed to create safe, solid-fueled propulsion systems with specifically tailored properties. Finally, the combination of expertise in combustion modeling, unsteady combustion, and advanced measurements will continue to generate significant advances in understanding and controlling combustion and propulsion systems.
