Computational Analysis of Circulation Control Airfoils

Computational Analysis of Circulation Control Airfoils
Author:
Publisher:
Total Pages:
Release: 2004
Genre:
ISBN:

Current projections for future aircraft concepts call for stringent requirements on high-lift and low cruise-drag. The purpose of this study is to examine the use of circulation control, through trailing edge blowing, to meet both requirements. This study was conducted in two stages: (i) validation of computational fluid dynamic procedures on a general aviation circulation control airfoil and (ii) a study of an adaptive circulation control airfoil for controlling lift coefficients in the low-drag range. In an effort to validate computational fluid dynamics procedures for calculating flows around circulation control airfoils, the commercial flow solver FLUENT was utilized to study the flow around a general aviation circulation control airfoil. The results were compared to experimental and computational fluid dynamics results conducted at the NASA Langley Research Center. This effort was conducted in three stages: (i) a comparison of the results for free-air conditions to those from previously conducted experiments, (ii) a study of wind-tunnel wall effects, and (iii) a study of the stagnation-point behavior. In general, the trends in the results from the current work agreed well with those from experiments, some differences in magnitude were present between computations and experiments. For the cases examined, FLUENT computations showed no noticeable effect on the results due to the presence of wind-tunnel walls. The study also showed that the leading-edge stagnation point moves in a systematic manner with changes to the jet blowing coefficient and angle of attack, indicating that this location can be sensed for use in closed-loop control of such airfoil flows. The focus of the second part of the study was to examine the use of adaptive circulation control on a natural laminar flow airfoil for controlling the lift coefficient of the low-drag range. In this effort, adaptive circulation control was achieved through blowing over a small mechanical flap that can be deflec.

Active Flow and Combustion Control 2018

Active Flow and Combustion Control 2018
Author: Rudibert King
Publisher: Springer
Total Pages: 380
Release: 2018-09-03
Genre: Technology & Engineering
ISBN: 3319981773

The book reports on the latest theoretical and experimental findings in the field of active flow and combustion control. It covers new developments in actuator technology and sensing, in robust and optimal open- and closed-loop control, as well as in model reduction for control, constant volume combustion and dynamic impingement cooling. The chapters reports oncutting-edge contributions presented during the fourth edition of the Active Flow and Combustion Control conference, held in September 19 to 21, 2018 at the Technische Universität Berlin, in Germany. This conference, as well as the research presented in the book, have been supported by the collaborative research center SFB 1029 on “Substantial efficiency increase in gas turbines through direct use of coupled unsteady combustion and flow dynamics”, funded by the DFG (German Research Foundation). It offers a timely guide for researchers and practitioners in the field of aeronautics, turbomachinery, control and combustion.

Fundamentals of High Lift for Future Civil Aircraft

Fundamentals of High Lift for Future Civil Aircraft
Author: Rolf Radespiel
Publisher: Springer Nature
Total Pages: 634
Release: 2020-10-17
Genre: Technology & Engineering
ISBN: 3030524299

This book reports on the latest numerical and experimental findings in the field of high-lift technologies. It covers interdisciplinary research subjects relating to scientific computing, aerodynamics, aeroacoustics, material sciences, aircraft structures, and flight mechanics. The respective chapters are based on papers presented at the Final Symposium of the Collaborative Research Center (CRC) 880, which was held on December 17-18, 2019 in Braunschweig, Germany. The conference and the research presented here were partly supported by the CRC 880 on “Fundamentals of High Lift for Future Civil Aircraft,” funded by the DFG (German Research Foundation). The papers offer timely insights into high-lift technologies for short take-off and landing aircraft, with a special focus on aeroacoustics, efficient high-lift, flight dynamics, and aircraft design.

On the Validation of a Code and a Turbulence Model Appropriate to Circulation Control Airfoils

On the Validation of a Code and a Turbulence Model Appropriate to Circulation Control Airfoils
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 26
Release: 2018-07-09
Genre:
ISBN: 9781722458652

A computer code for calculating flow about a circulation control airfoil within a wind tunnel test section has been developed. This code is being validated for eventual use as an aid to design such airfoils. The concept of code validation being used is explained. The initial stages of the process have been accomplished. The present code has been applied to a low-subsonic, 2-D flow about a circulation control airfoil for which extensive data exist. Two basic turbulence models and variants thereof have been successfully introduced into the algorithm, the Baldwin-Lomax algebraic and the Jones-Launder two-equation models of turbulence. The variants include adding a history of the jet development for the algebraic model and adding streamwise curvature effects for both models. Numerical difficulties and difficulties in the validation process are discussed. Turbulence model and code improvements to proceed with the validation process are also discussed. Viegas, J. R. and Rubesin, M. W. and Maccormack, R. W. Ames Research Center RTOP 505-60-11...

Turbulence Structure and Modulation

Turbulence Structure and Modulation
Author: Alfredo Soldati
Publisher: Springer Science & Business Media
Total Pages: 332
Release: 2001-07-19
Genre: Computers
ISBN: 9783211833391

Controlling turbulence is an important issue for a number of technological applications. Several methods to modulate turbulence are currently being investigated. All of them are based on the introduction of some sort of perturbation into the flow field which affect turbulence coherent structures responsible for turbulence transfer mechanisms. The scope of the book is to describe several aspects of turbulence structure and modulation and to explain and discuss the most promising techniques in detail.

Applications of Circulation Control Technologies

Applications of Circulation Control Technologies
Author: Ronald Douglas Joslin
Publisher: AIAA (American Institute of Aeronautics & Astronautics)
Total Pages: 656
Release: 2006
Genre: Science
ISBN:

Based on papers from the 2004 NASA/ONR Circulation Control Workshop, this collection is an invaluable, one-of-a-kind resource on the state of the art in circulation control technologies and applications. Filling the information gap between 1986 -- when the last such symposium was held -- and today, it summarizes the applications, experiments, computations and theories related to circulation control, emphasizing fundamental physics, systems analysis and applied research. The papers presented cover a wide variety of aerodynamic and hydrodynamic applications including naval vehicles, fixed-wing aviation, V/STOL platforms, propulsion systems and ground vehicles. Anyone with interests in applied aerodynamics, fluid mechanics and aircraft design will find this book of particular value, as will those seeking a an up-to-date reference work on circulation control and its many current applications.

An Assessment of Circulation Control Airfoil Development

An Assessment of Circulation Control Airfoil Development
Author: Joseph B. Wilkerson
Publisher:
Total Pages: 100
Release: 1977
Genre: Aerofoils
ISBN:

A circulation control (CC) airfoil development program is presented, including an airfoil designation system. Specific performance objectives are set forth as development goals. Background information includes an assessment of state-of-the-art design practices, a comparison of operational requirements with those of conventional airfoils, and a discussion of previous airfoil performance. Selection and design criteria are described for five new CC airfoils. These designs were wind tunnel evaluated as two-dimensional models and a limited amount of airfoil data is shown for comparison to the prior data base. Two of the airfoils were designed with the objective of maintaining high lift augmentation and improving the critical Mach number characteristics, a combination of qualities that was previously nonexistent. Both designs theoretically accomplished the prescribed goals and were validated by experimental results. The development program has advanced the state of the art and nearly doubled the available data base for CC airfoils. (Author).