A Real-time Method for Estimating Viscous Forebody Drag Coefficients

A Real-time Method for Estimating Viscous Forebody Drag Coefficients PDF Author: Stephen A. Whitmore
Publisher:
ISBN:
Category : Drag (Aerodynamics)
Languages : en
Pages : 36

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Book Description
This paper develops a real-time method based on the law of the wake for estimating forebody skin-friction coefficients. The incompressible law-of-the-wake equations are numerically integrated across the boundary layer depth to develop an engineering model that relates longitudinally averaged skin-friction coefficients to local boundary layer thickness. Solutions applicable to smooth surfaces with pressure gradients and rough surfaces with negligible pressure gradients are presented. Model accuracy is evaluated by comparing model predictions with previously measured flight data. This integral law procedure is beneficial in that skin-friction coefficients can be indirectly evaluated in real-time using a single boundary layer height measurement. In this concept a reference pitot probe is inserted into the flow, well above the anticipated maximum thickness of the local boundary layer. Another probe is servomechanism-driven and floats within the boundary layer. A controller regulates the position of the floating probe. The measured servomechanism of this second probe provides an indirect measurement of both local and longitudinally averaged skin friction. Simulation results showing the performance of the control law for a noisy boundary layer are then presented.

A Real-time Method for Estimating Viscous Forebody Drag Coefficients

A Real-time Method for Estimating Viscous Forebody Drag Coefficients PDF Author: Stephen A. Whitmore
Publisher:
ISBN:
Category : Drag (Aerodynamics)
Languages : en
Pages : 36

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Book Description
This paper develops a real-time method based on the law of the wake for estimating forebody skin-friction coefficients. The incompressible law-of-the-wake equations are numerically integrated across the boundary layer depth to develop an engineering model that relates longitudinally averaged skin-friction coefficients to local boundary layer thickness. Solutions applicable to smooth surfaces with pressure gradients and rough surfaces with negligible pressure gradients are presented. Model accuracy is evaluated by comparing model predictions with previously measured flight data. This integral law procedure is beneficial in that skin-friction coefficients can be indirectly evaluated in real-time using a single boundary layer height measurement. In this concept a reference pitot probe is inserted into the flow, well above the anticipated maximum thickness of the local boundary layer. Another probe is servomechanism-driven and floats within the boundary layer. A controller regulates the position of the floating probe. The measured servomechanism of this second probe provides an indirect measurement of both local and longitudinally averaged skin friction. Simulation results showing the performance of the control law for a noisy boundary layer are then presented.

The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains

The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains PDF Author: Rose McCallen
Publisher: Springer Science & Business Media
ISBN: 354044419X
Category : Technology & Engineering
Languages : en
Pages : 534

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Book Description
It is our pleasure to present these proceedings from the United Engineering Foundation Conference on The Aerodynamics of Heavy Vehicles: Trucks, Buses and Trains held December 2-6, 2002, in Monterey, California. This Department of Energy, United Engineering Foundation, and industry sponsored conference brought together 90 leading engineering researchers from around the world to discuss the aerodynamic drag of heavy vehicles. Participants from national labs, academia, and industry, including truck manufacturers, discussed how computer simulation and experimental techniques could be used to design more fuel efficient trucks, buses, and trains. Conference topics included comparison of computational fluid dynamics calculations using both steady and unsteady Reynolds-averaged Navier-Stokes, large-eddy simulation, and hybrid turbulence models and experimental data obtained from the Department of Energy sponsored and other wind tunnel experiments. Advanced experimental techniques including three-dimensional particle image velocimetry were presented, along with their use in evaluating drag reduction devices. We would like to thank the UEF conference organizers for their dedication and quick response to sudden deadlines. In addition, we would like to thank all session chairs, the scientific advisory committee, authors, and reviewers for their many hours of dedicated effort that contributed to a successful conference and resulted in this document of the conference proceedings. We also gratefully acknowledge the support received from the United Engineering Foundation, the US Department of Energy, Lawrence Livermore National Laboratory, Volvo Trucks America, International Truck and Engine Corporation, and Freightliner LLC.

Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 948

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38th Aerospace Sciences Meeting and Exhibit

38th Aerospace Sciences Meeting and Exhibit PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 606

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21st AIAA Advanced Measurement and Ground Testing Technology Conference: 00-2375 - 002527

21st AIAA Advanced Measurement and Ground Testing Technology Conference: 00-2375 - 002527 PDF Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 616

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702

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Twenty-Second Symposium on Naval Hydrodynamics

Twenty-Second Symposium on Naval Hydrodynamics PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309065372
Category : Science
Languages : en
Pages : 1039

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Book Description
The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.

Technical Abstract Bulletin

Technical Abstract Bulletin PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 952

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Technical digest

Technical digest PDF Author: Naval Surface Warfare Center (U.S.). Dahlgren Division
Publisher:
ISBN:
Category :
Languages : en
Pages : 180

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International Aerospace Abstracts

International Aerospace Abstracts PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 940

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