NASA SBIR 2003 Solicitation


PROPOSAL NUMBER:03-A2.06-8614 (For NASA Use Only - Chron: 034391)
SUBTOPIC TITLE:Modeling and Control of Complex Flows Over Aerospace Vehicles and Propulsion Systems
PROPOSAL TITLE:Low Mach Scramjet Cavity Flameholder Stabilization

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
TDA Research, Inc.
12345 West 52nd Ave
Wheat Ridge ,CO 80033 - 1916
(303) 422 - 7819

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Mr. James   Nabity
12345 W. 52nd Ave.
Wheat Ridge ,CO  80033 -1916
(303) 940 - 2313
U.S. Citizen or Legal Resident: Yes

This proposal addresses a NASA solicitation topic A2.06 need for propulsion system flow control. A dual mode ram/scram engine is the most likely cycle for the high-speed propulsion flowpath of turbine and rocket based combined cycle engines, but its feasibility with storable liquid hydrocarbon fuels remains to be demonstrated. A key reason is that a stable, low drag engine pilot for the needed operational envelope has eluded us. Due to its simplicity, the cavity flameholder is the subject of renewed investigation, but it suffers from acoustically coupled combustion instabilities originating in the shear flow. Active control of the shear flow over the cavity could substantially improve flameholding stability. Therefore, TDA Research, Inc. (TDA) proposes an active control strategy having no moving parts to manipulate the spectral content and amplitude of shear layer disturbances, and hence control the coupling responsible for resonance and unsteady flow response that leads to premature flame extinguishment. The proposed experimental and analytical development effort will produce a robust, stable and low drag scramjet engine pilot.

The control of shear layer dynamics is central to all cavity-flow control strategies due to coupling between the separated shear layer dynamics and cavity resonance characteristics. Therefore, the cavity flow stabilization technology proposed by TDA has wide-spread application to combustion flameholding and acoustic noise reduction. For example, future high speed aircraft powered by turbine-based combined cycle engines would benefit from low Mach transition to scramjet mode. In addition, the aircraft wheel wells are a large source of noise pollution during take-off and landing, which could be alleviated through shear layer control.

Countercurrent shear layer technology has also been shown to be effective in thrust vector control (TVC) resulting in increased aircraft agility. Improved short takeoff and landing capability for military aircraft is expected because of increased lift from a TVC system.

We can also apply this technology to automotive noise reduction for neighborhood and passenger comfort. Noise due to separated flow in wheel wells and off of side mirrors could be reduced.

In addition, a counterflow TVC system can increase missile agility resulting in reduced time-to-target and increased probability of kill.