Review of advances in combustion control, actuation, sensing, modeling and related technologies for air breathing gas turbines

Abstract

For more than 50 years active combustion control has been studied for attenuation of combustion instabilities. Current and future combustion systems require more than control of combustion instabilities to meet ever expanding and increasing goals. For aero-gas turbine engines applications such as control of combustor exit temperature distribution, control of combustion instabilities, and control of pollutant emissions and engine health management (EHM) are just a few. Combustion control can be used to enhance performance and increase the durability of gas turbine engines. Combustion control can impact performance goals such as increased thrust, and reduced thrust specific fuel consumption (tsfc). It can also impact durability and Life Cycle Cost (LCC) through control of pattern factor and combustor exhaust profile.Combustion control applications require many technology approaches to be realized before different combustion control can be implemented in military of commercial gas turbines. Tlie readiness of actuation technology is probably the long pole technology for many of the combustion control application. Advances in sensor technology will also be required. Actual combustor exit measurements would be most beneficial to differentiating between combustor and high pressure turbine performance. Non-intrusive sensors to detect combustion products and intermediates will be useful as inputs to advanced control systems. Advanced models and controls probably have the highest state of readiness, probably because so much past time and resources have been focused in this area. Continued effort is warranted developing models based on realistic physics with estimation of uncertainty and noise.

Development of a Piezoelectric-actuated Fuel Modulation System for Active Combustion Control

“…Using this technique, the fuel is pulsed to produce heat release rate oscillations that damp the pressure fluctuations in the combustion chamber. Extensive surveys of recent active combustion control (ACC) techniques are found in Candel (1992), McManus et al (1993), Zinn and Neumeier (1997), and Kiel (2001).…”

Piezoelectric Ceramics for High Temperature Actuators

“…Piezoelectricity can be defined as stress (a) induced electrical displacement (D) (direct effect, Eqn. 1) or electric field (E) induced strain (s)(converse effect, Eqn. 2).…”

Sensor Needs for Control and Health Management of Intelligent Aircraft Engines

“…Active Combustion Control which consists of feedback-based control of the fuel injection, the fuel-air mixing process, and the staging of fuel sources, can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. Reference [12] provides a review of active combustion control, and discusses current capabilities and future advances required in the related technology areas of control, modeling, actuation, and sensing. The three main areas of interest in active combustion control are: combustion instability control, emission minimizing control, and pattern factor control [13].…”

“…A secondary option is to use pressure sensors through which the level of emission production can be inferred. Reference [12] discussed the use of laser diodes, planar laser-induced fluorescence, chemiluminescence, and Fourier Transform Infrared spectrometry as potential emission species measurement options. Example specifications are shown in Table 1.…”