Small Disturbance Transonic Flows About Oscillating Airfoils and Planar Wings PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Small Disturbance Transonic Flows About Oscillating Airfoils and Planar Wings PDF full book. Access full book title Small Disturbance Transonic Flows About Oscillating Airfoils and Planar Wings by R. M. Traci. Download full books in PDF and EPUB format.
Author: R. M. Traci Publisher: ISBN: Category : Languages : en Pages : 179
Book Description
A theory and numerical solution method are presented for the problem of two or three dimensional flow about thin wings undergoing harmonic oscillations. The theory is based on a treatment of the unsteady flow as a small perturbation on the nonlinear steady flow. The coupled governing equations for the steady and unsteady perturbation potentials are of mixed elliptic/hyperbolic type and are solved using the mixed differencing line relaxation techniques of Murman and Cole. The theory and solution method have been generalized to treat subsonic or supersonic freestream flows, solid or porous wall effects and three dimensional flow about planar wings. Calculations demonstrating each of these capabilities are presented. Accuracy of the method for realistic steady and unsteady flows is examined by comparison to more exact numerical results and experimental data. The comparison indicates that the present method provides a useful and efficient inviscid solution. Quantitative differences between the present results and experimental data are attributed primarily to viscous effects, pointing out the importance of such effects for transonic flows.
Author: R. M. Traci Publisher: ISBN: Category : Languages : en Pages : 179
Book Description
A theory and numerical solution method are presented for the problem of two or three dimensional flow about thin wings undergoing harmonic oscillations. The theory is based on a treatment of the unsteady flow as a small perturbation on the nonlinear steady flow. The coupled governing equations for the steady and unsteady perturbation potentials are of mixed elliptic/hyperbolic type and are solved using the mixed differencing line relaxation techniques of Murman and Cole. The theory and solution method have been generalized to treat subsonic or supersonic freestream flows, solid or porous wall effects and three dimensional flow about planar wings. Calculations demonstrating each of these capabilities are presented. Accuracy of the method for realistic steady and unsteady flows is examined by comparison to more exact numerical results and experimental data. The comparison indicates that the present method provides a useful and efficient inviscid solution. Quantitative differences between the present results and experimental data are attributed primarily to viscous effects, pointing out the importance of such effects for transonic flows.
Author: F. Edward Ehlers Publisher: ISBN: Category : Aerodynamics, Transonic Languages : en Pages : 88
Book Description
A finite difference method for the solution of the transonic flow about a harmonically oscillating wing is presented. The partial differential equation for the unsteady transonic flow was linearized by dividing the flow into separate steady and unsteady perturbation velocity potentials and by assuming small amplitudes of harmonic oscillation. The resulting linear differential equation is of mixed type, being elliptic or hyperbolic whereever the steady flow equation is elliptic or hyperbolic. Central differences were used for all derivatives except at supersonic points where backward differencing was used for the streamwise direction. Detailed formulas and procedures are described in sufficient detail for programming on high speed computers. To test the method, the problem of the oscillating flap on a NACA 64A006 airfoil was programmed. The numerical procedure was found to be stable and convergent even in regions of local supersonic flow with shocks.
Author: Jürgen Zierep Publisher: Springer Science & Business Media ISBN: 3642835848 Category : Science Languages : en Pages : 503
Book Description
Continuing the tradition of the IUTAM Symposia TRANSSONICA, this review of the numerical simulation and physical modelling of transonic flows presents new developments in the fields of computational and experimental aerodynamics. A major topic of the symposium proceedings is the evaluation of present numerical analysis techniques with respect to transonic aerodynamics. In the field of experimental aerodynamics, the high Reynolds number effect and the interference-free testing in transonic wind tunnels are of special interest.
Author: J. L. Farr (Jr.) Publisher: ISBN: Category : Aerodynamics, Transonic Languages : en Pages : 140
Book Description
Computer programs are described which implement a small disturbance potential flow theory for the two-dimensional unsteady transonic flow about thin airfoils undergoing low reduced frequency harmonic oscillations. The theory is based upon the treatment of the unsteady flow as a small perturbation to the steady transonic flow. Separating the perturbation potential into a steady and unsteady component results in a pair of coupled boundary value problems for the components. The governing equation for the steady perturbation potential is the usual nonlinear transonic potential equation and it is solved in computer program STRANS using the mixed differencing relaxation procedure of Murman and Cole. The governing equation for the unsteady perturbation potential is linear and, for the harmonic boundary disturbance considered, of mixed elliptic hyperbolic type depending on the local nature of the steady potential. Using a steady solution previously generated by STRANS, computer program UTRANS solves the unsteady potential equation by the same relaxation procedure. The solution procedures are found to be quite efficient, permitting the calculation of unsteady aerodynamic forces to engineering accuracy in a few minutes on a CDC 6600 computer.
Author: R. M. Traci
Author: R. M. Traci
Author: F. Edward Ehlers
Author: F. Edward Ehlers
Author: Jürgen Zierep
Author: 
Author: 
Author: J. L. Farr (Jr.)
Author: 
Author: 
Author: