NASA SBIR 2007 Solicitation


PROPOSAL NUMBER: 07-1 A2.02-9405
SUBTOPIC TITLE: Combustion for Aerospace Vehicles
PROPOSAL TITLE: Turbulent Scalar Transport Model Validation for High Speed Propulsive Flows

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Combustion Research and Flow Technology
6210 Keller's Church Road
Pipersville, PA 18947 - 2010
(215) 766-1520

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
William Calhoon
3313 Memorial Parkway S, Suite 108
Huntsville, AL 35801 - 5375
(256) 883-1905

Expected Technology Readiness Level (TRL) upon completion of contract: 2 to 3

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
This effort entails the validation of a RANS turbulent scalar transport model (SFM) for high speed propulsive flows, using new experimental data sets and accompanying large-eddy simulation (LES) solutions. The SFM has been used to predict local values of the turbulent Prandtl and Schmidt numbers and also provides the rms scalar fluctuation values that are used with assumed PDF models for turbulent combustion. Performing the experimental work in unison with LES studies ensures that the two sets of data will be fully compatible, and may be used to support SFM model validation. Work to date indicates some deficiencies in the present SFM model for high speed mixing problems where the two streams have very different densities, which we will attempt to resolve in this program. PIV data for the transverse injection of hot air and helium/nitrogen mixtures into a Mach 3.5 stream will be obtained in unison with LES studies to yield scalar fluctuation data not readily obtained in experiments. SFM upgrades will be performed using this unified data. Experiments will be performed by Dr. Seiner and coworkers at U. Miss using a new 12"x12" trisonic tunnel and existing slot/round jet injector models.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
A validated scalar fluctuation model (SFM) has potential post applications to support design optimization and concept evaluation for scramjet fuel injection systems, where use of current models does not provide the accuracy required, typically underestimating fuel/air mixing. Use of the SFM alleviates the need to somewhat arbitrarily specify values of Prandtl and Schmidt number, whose values have a first-order effect on predicted performance and hence on optimizing designs, and also provides the fluctuations needed to include in assumed PDF turbulent combustion models. Other NASA applications entail use of the SFM in improving the design of launch vehicles for thermal protection where plume heating effects in the base region are a major design issue, as well as many other applications involving fuel/air mixing and plume effects.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
From a DoD perspective, we are involved in Army and Air Force sponsored scramjet propulsive system design programs focusing on fuel injector optimization. Having a more reliable SFM will lead to better designs since the fuel/air mixing will be predicted more accurately. We are also involved in interceptor missile design activities supported by the Missile Defense Agency, where plume heating effects are problematic and are requiring the use of ablative shields. We require accurate estimates of plume afterburning which is directly related to plume/air entrainment rates and thus to turbulent Prandtl and Schmidt numbers. This work will provide us with a more accurate tool to support DoD, and, it will enhance our code licensing and prime contractor support activities since a validated SFM provides improvements in predictive capabilities for a broad variety of high speed mixing problems.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Fundamental Propulsion Physics
Simulation Modeling Environment
Testing Facilities

Form Generated on 09-18-07 17:50