Active Turbulence Control in Wall Bounded Flows Using Direct Numerical Simulation

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Abstract:

The objective of the study is to explore concepts for control of turbulent boundary layers leading to skin-friction reduction using the direct numerical simulation technique. This report is divided into three parts where different control methods are investigated an active control by sensing and perturbing structures near the wall, a feedback control procedure guided by control theory, and a passive control by longitudinal riblets. Part I significant drag reduction is achieved when the surface boundary condition is modified to suppress the dynamically significant coherent structures present in the wall region. Part II mathematical methods of control theory are applied to the problem of control of fluid flow. Part III direct numerical simulation is performed to analyze turbulent flow over longitudinal riblets, and to educe the mechanism of drag reduction by riblets. TF-55 Turbulent Drag Reduction Studies of Feedback Control and Flow Over Riblets by Haecheon Choi, Parviz Moin and John Kim.... Turbulent drag reduction, Feedback control, Passive control Riblet.

Author(s):
Moin, Parviz
Author Organization(s):
STANFORD UNIV CA THERMOSCIENCES DIV
Descriptive Note:
Final technical rept. 1 Jul 89-30 Sep 92,
Pagination:
0291

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFOSR-TR-93-0467
Contract/Grant Number(s):
AFOSR-89-0411
Task Number(s):
BS
Project Number(s):
2307
Monitor Series:
TR-93-0467, AFOSR
 Subject Terms
Joint Capability Areas:
JCA_5_Command and Control; JCA_5.3_Planning; JCA_3.2_Engagement; JCA_3_Force Application; JCA_3.2.1_Kinetic Means; JCA_5.3.3_Develop Strategy; JCA_1_Force Support; JCA_6.3.3_Spectrum Management; JCA_1.2.7_Experimentation; JCA_1.2_Force Preparation; JCA_6_Net Centric; JCA_5.3.4_Develop Courses of Action; JCA_5.3.5_Analyze Courses of Action; JCA_6.3_Net Management; JCA_1.3_Human Capital Management; JCA_1.3.2_Personnel Management; JCA_5.4_Decide; JCA_1.2.5_Lessons Learned; JCA_5.2.2_Develop Knowledge and Situational Awareness; JCA_5.2_Understand; JCA_5.4.5_Intuit
Modernization Areas:
Cyber
Communities of Interest:
Cyber
Descriptor(s):
*TURBULENT FLOW, *TURBULENT BOUNDARY LAYER, *SKIN FRICTION, *DRAG REDUCTION, MATHEMATICAL MODELS, SIMULATION, SURFACES, FEEDBACK, CONTROL THEORY, NAVIER STOKES EQUATIONS, REYNOLDS NUMBER, RIBS, FLUID FLOW, FRICTION, DRAG, WALLS, BOUNDARIES, LAYERS, BOUNDARY LAYER, TURBULENCE
Field(s)/Group(s):
Fluid Mechanics
Keyword(s):
WUAFOSR2307BS, SHEAR FLOW
Report Date:
1992 Nov 06