USA flag logo/image

An Official Website of the United States Government

A NEW SUBGRID MODEL FOR LARGE-EDDY SIMULATIONS OF MIXING AND CHEMICAL REACTION…

Award Information

Agency:
National Aeronautics and Space Administration
Branch:
N/A
Award ID:
16868
Program Year/Program:
1991 / SBIR
Agency Tracking Number:
16868
Solicitation Year:
N/A
Solicitation Topic Code:
N/A
Solicitation Number:
N/A
Small Business Information
QUEST Integrated
19823 58th Place S., Suite 200 Kent, WA -
View profile »
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
 
Phase 1
Fiscal Year: 1991
Title: A NEW SUBGRID MODEL FOR LARGE-EDDY SIMULATIONS OF MIXING AND CHEMICAL REACTION IN TURBULENT FLOWS
Agency: NASA
Contract: N/A
Award Amount: $49,941.00
 

Abstract:

CONVENTIONAL, TURBULENT-MIXING MODELS BASED ON GRADIENT-DIFFUSION ASSUMPTIONS ARE NOT CAPABLE OF ACCURATELY PREDICTING MIXING AND REACTION RATES IN MOST PRACTICAL COMBUSTION DEVICES. FURTHERMORE, AT THE SMALL SCALES, MOST CONVENTIONAL MODELS MAKE NO DISTINCTION BETWEENTURBULENT CONVERSION AND MOLECULAR DIFFUSION. THIS DISTINCTION IS CRITICAL FOR THE ACCURATE DESCRIPTION OF THE MIXING PROCESS. IN ADDITION, IT IS KNOWN THAT TURBULENTMIXING AND ENTRAINMENT PROCESSES IN SHEAR FLOWS ARE DOMINATED BY UNSTEADY, LARGE-SCALE, VORTICAL MOTIONS. THE SPATIAL AND TEMPORAL EVOLUTION OF THESE LARGE-SCALE STRUCTURES CANNOT BE MODELED AND MUST BE EXPLICITLY COMPUTED FOR ACCURATE PREDICTIONS. PHASE I WILL EXPLORE SUBGRID MODELING TECHNIQUES FOR USE IN LARGE-EDDY SIMULATION (LES) OF REACTING FLOWS. IN PARTICULAR, A MODEL FOR MIXING AND CHEMICAL REACTIONS AT THE SUBGRID LEVEL IN BOTH LOW- AND HIGH-SPEED FLOWS WILL BE DEVELOPED BASED ON KERSTEIN'S LINEAR-EDDY APPROACH. LES OF INCOMPRESSIBLE, TWO-DIMENSIONAL MIXING LAYERS WILL BE PERFORMED, AND THE RESULTS WILL BE COMPARED WITH HIGH-RESOLUTION, DIRECT NUMERICAL SIMULATIONS AND AVAILABLE EXPERIMENTAL DATA TO ASSESS THE PROPOSED SUBGRID MODEL. THIS MODEL WOULD BE EXTENDED TO STUDY THREE-DIMENSIONAL, COMPRESSIBLE REACTING FLOWS WITH HEAT RELEASE IN PHASE II. CONVENTIONAL, TURBULENT-MIXING MODELS BASED ON GRADIENT-DIFFUSION ASSUMPTIONS ARE NOT CAPABLE OF ACCURATELY PREDICTING MIXING AND REACTION RATES IN MOST PRACTICAL COMBUSTION DEVICES. FURTHERMORE, AT THE SMALL SCALES, MOST CONVENTIONAL MODELS MAKE NO DISTINCTION BETWEENTURBULENT CONVERSION AND MOLECULAR DIFFUSION. THIS DISTINCTION IS CRITICAL FOR THE ACCURATE DESCRIPTION OF THE MIXING PROCESS. IN ADDITION, IT IS KNOWN THAT TURBULENTMIXING AND ENTRAINMENT PROCESSES IN SHEAR FLOWS ARE DOMINATED BY UNSTEADY, LARGE-SCALE, VORTICAL MOTIONS. THE SPATIAL AND TEMPORAL EVOLUTION OF THESE LARGE-SCALE STRUCTURES CANNOT BE MODELED AND MUST BE EXPLICITLY COMPUTED FOR ACCURATE PREDICTIONS. PHASE I WILL EXPLORE SUBGRID MODELING TECHNIQUES FOR USE IN LARGE-EDDY SIMULATION (LES) OF REACTING FLOWS. IN PARTICULAR, A MODEL FOR MIXING AND CHEMICAL REACTIONS AT THE SUBGRID LEVEL IN BOTH LOW- AND HIGH-SPEED FLOWS WILL BE DEVELOPED BASED ON KERSTEIN'S LINEAR-EDDY APPROACH. LES OF INCOMPRESSIBLE, TWO-DIMENSIONAL MIXING LAYERS WILL BE PERFORMED, AND THE RESULTS WILL BE COMPARED WITH HIGH-RESOLUTION, DIRECT NUMERICAL SIMULATIONS AND AVAILABLE EXPERIMENTAL DATA TO ASSESS THE PROPOSED SUBGRID MODEL. THIS MODEL WOULD BE EXTENDED TO STUDY THREE-DIMENSIONAL, COMPRESSIBLE REACTING FLOWS WITH HEAT RELEASE IN PHASE II.

Principal Investigator:


0

Business Contact:

Small Business Information at Submission:

Quest Integrated Inc
21414 68th Ave S Kent, WA 98032

EIN/Tax ID:
DUNS: N/A
Number of Employees: N/A
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No