Numerical Investigation of Flow Control Over an Airfoil

Numerical Investigation of Flow Control Over an Airfoil
Author: Eray AKÇAYÖZ
Publisher: LAP Lambert Academic Publishing
Total Pages: 88
Release: 2010-05
Genre:
ISBN: 9783838356013

The synthetic jet is applied over an airfoil to control the flow separation. Response Surface Methodology is employed for the optimization of synthetic jet parameters at various angles of attack. The synthetic jet parameters; the jet velocity, the jet location, the jet angle and the jet frequency are optimized to maximize the lift to drag ratio. The jet power coefficient is kept constant in the optimization. The lift to drag ratio increased significantly especially at post stall angles of attack.

Numerical Investigation of Active Flow Control Applied to an Airfoil Leading Edge

Numerical Investigation of Active Flow Control Applied to an Airfoil Leading Edge
Author: Bhanu Prakash Reddy Samala
Publisher:
Total Pages:
Release: 2015
Genre:
ISBN:

Objectives: The major objective of the Master Thesis proposal is to perform 2D computational study and compare the enhancement in the global aerodynamic coefficients, mainly lift and drag coefficients, for cases of with and without Active Flow Control (AFC). The focus is also on various cases of parameters of active flow control i.e, frequency of fluid ejection, jet velocity from actuator and location of slots for actuators for delaying the airfoil leading edge separation. Introduction: In the present context, the focused area is an airfoil of a regular commercial plane. The major concern while conducting experimental or numerical fluid dynamics study with the airfoils is to delay the separation of air (fluid) on both of the pressure sides on wing. The two main locations where the separation of fluid have an impact on global lift and drag coefficients include the leading edge boundary layer and the separation on the trailing edge flap.(Ciobaca & Wild, 2013). The techniques to delay the separation layer are of two major types which include Active Flow Control(AFC) and Passive Flow Control (PFC) (Jansen, 2012). The reason to choose AFC for this case is the reliability of the technique for all the future developments in various sectors like aerospace, automobile, wind energy etc (Nasa Website news 2013 [5][6]). Active Flow Control is becoming a viable tool for modifying flows for many practical applications. Active flow control can enable the design of simpler, smaller and more aerodynamically efficient structures that help reduce aircraft weight, drag, and fuel consumption. It typically refers to the use of time-dependent (often periodic) disturbances that are introduced into the flow field by the actuators. Also, AFC modifies the flow by adding energy (blowing) or by removing energy (suction). Methodology: As aforementioned, the proposed thesis focus is on computational study of the airfoil leading edge boundary layer with and without AFC. The variation of global lift and drag coefficients on varying the parameters of Active Flow Control like frequency, jet velocity and location of slots. The research conducted by (Burt Gunther et.al 2010) on AFC for airfoil flap will be used as guidance for conducting the similar test cases for Leading Edge AFC. The preliminary results from the computational model will be compared with the existing experimental results obtained at TU Braunschweig and DLR, Germany (Ciobaca & Wild, 2013) to check the accuracy and reliability of the numerical simulation results in order to further contribute to the existing state of the art results. To develop the computational model, the NACA2412 is chosen. The initial focus is on incompressible flow conditions by choosing the appropriate turbulence model and other numerical methods for solving Unsteady Reynolds Averaged Navier Stokes (URANS) Equations. Depending upon the accuracy of the results when compared with the experimental results, there will always be a flexibility to improvise the results using more computationally intensive numerical methods. The major software tools that will be used include a combination of ANSYS Fluent and OpenFOAM. References: 1. Ciobaca, V., & Wild, J. (2013). An Overview of Recent DLR Contributions on Active Flow-Separation Control Studies for High- Lift Configurations, (6), 1-12. 2. Generators, V., & Jansen, D. P. (2012). Passive Flow Separation Control on an Airfoil-Flap Model, (August). 3. Nagib, P. H. M., Kiedaisch, J. W., Wygnanski, P. I. J., Stalker, A. D., Wood, T., & Mcveigh, M. A. (n.d.). First-In- Flight Full-Scale Application of Active Flow Control : The XV-15 Tiltrotor Download Reduction.

Advances in Effective Flow Separation Control for Aircraft Drag Reduction

Advances in Effective Flow Separation Control for Aircraft Drag Reduction
Author: Ning Qin
Publisher: Springer Nature
Total Pages: 341
Release: 2019-10-17
Genre: Technology & Engineering
ISBN: 3030296881

This book presents the results of a European-Chinese collaborative research project, Manipulation of Reynolds Stress for Separation Control and Drag Reduction (MARS), including an analysis and discussion of the effects of a number of active flow control devices on the discrete dynamic components of the turbulent shear layers and Reynolds stress. From an application point of view, it provides a positive and necessary step to control individual structures that are larger in scale and lower in frequency compared to the richness of the temporal and spatial scales in turbulent separated flows.

Flow Control

Flow Control
Author: Mohamed Gad-el-Hak
Publisher: Cambridge University Press
Total Pages: 445
Release: 2000-08-15
Genre: Science
ISBN: 0521770068

A thorough treatment of the basics of flow control and flow control practices.

Flow Control Techniques and Applications

Flow Control Techniques and Applications
Author: Jinjun Wang
Publisher: Cambridge University Press
Total Pages: 293
Release: 2019
Genre: Science
ISBN: 1107161568

Master the theory, applications and control mechanisms of flow control techniques.

Boundary Value Problems for Transonic Flow

Boundary Value Problems for Transonic Flow
Author: Alexander G Kuz'min
Publisher: John Wiley & Sons
Total Pages: 316
Release: 2003-02-28
Genre: Technology & Engineering
ISBN: 047085295X

Transonic flow occurs around moving objects as they approach and cross the sound barrier. Serious problems can occur at this point, such as shock-induced flow separation which can cause the aircraft to spin out of control. Another important practical problem is the achievement of higher aerodynamic performance of aircraft at cruise conditions, which leads to considerable fuel savings. The success in application of numerical methods for simulation of transonic flow and aircraft design depends on developments in the underlying mathematical theory. This book presents a breakthrough in the solvability analysis of boundary value problems, which makes it possible to establish convergence of finite element approximations for shock-free flow and to provide a framework for putting the existing numerical methods on a more sound basis. Also, physical aspects concerned with patterns of formation and propagation of weak shock waves are analysed. This contributes to the understanding of the extreme sensitivity of transonic flow to perturbation of freestream conditions. The developed theoretical knowledge base yields promising concepts of the airfoil design and active flow control by airfoil/wing shape modifications or suction/blowing through a perforated surface. Boundary Value Problems for Transonic Flow * Focuses on Computational Fluid Dynamics. * Addresses practical problems, such as airfoil design and flow control. * Presents developments made in the last two decades. In essence this is a much needed monograph for researchers and engineers in applied mathematics and numerical analysis applied to aerodynamics and for algorithm developers in Computational Fluid Dynamics in the aircraft industry. It gives design engineers the underlying mathematical theory necessary for developing new concepts for airfoil/wing design and flow control.