Active Combustion Control Valve

Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the operational range of gas-turbine combustors. Active Combustion Instability Control (ACIC) controls the combustion process such that the heat release profile is modulated to dampen the naturally occurring thermoacoustic instabilities. A major challenge to effective implementation of active combustion control is the availability of valves and actuators that provide adequate flow modulation control authority. The majority of the published work revolves around valves designed to modulate the main combustor flow. At present these valves are not designed to operate in a harsh environment and as such are required to be located outside the main flow path, reducing their control authority. To effectively meet the challenge, valves and sensors that are smaller, more responsive and robust must be developed. Ultimately the control valves are co-located with the fuel injection manifold. The trade-off for the harsh environment operation is the ability to maximize the flow modulation control authority. The objective of this research is to integrate the required control authority into an operational environment. This research initiates the development of a light weight fast-acting fuel control valve for harsh environment operation. The valve will allow the precise time dependent fuel control required for lean-burn combustor operability. In this Phase I research a proof-of-concept valve is designed, fabricated and cold-flow tested using commercially-available driver circuitry to uncover potential performance benefits and demonstrate feasibility of the approach for further development.

NASA, specifically the Controls and Dynamics branch at GRC, is actively engaged in Active Combustion Instability Control research. NASA is currently focusing on low emission lean-burn combustor design along with the application of ACIC techniques to increase the operating range of said combustors. The proposed harsh environment valves enable the application of the ACIC techniques due to the fact that the actuators, being closed-coupled to the fuel injector, have the required flow modulation control authority to implement the control schemes.

Operational gas turbine combustors, including augmentors, are prone to thermoacoustic instabilities. Therefore, companies such as GE, PW and Rolls Royce, are actively investigating ACIC. The valves developed for the lean-burn combustor fuel control can also be used to provide the control authority required to implement ACIC techniques into existing product lines of not only the gas turbine manufactures listed above, but other engine manufacturers as well.

This is early/mid-stage (TRL 4) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.