Author: Richard M. James Publisher: ISBN: Category : Languages : en Pages : 276
Book Description
The report represents an interim stage of a research program sponsored by ONR to try and put the basic mathematics of design and flow analysis methods for two-element airfoil systems on an equivalent footing to that of single element configurations with the ultimate end in view of producing 'optimum' designs. Techniques of conformal mapping and multiple image reflection are used to solve problems connected with two disjoint circles and then to develop the integral equations describing problems of real interest posed in a canonical domain -- the annular space between two concentric circles. Using this point of view, the essential character of a promising general technique is deduced. (Modified author abstract).
Author: R. M. James Publisher: ISBN: Category : Languages : en Pages : 86
Book Description
By using a general form of conformal mapping from the doubly-connected airfoil domain to the canonical ring domain, the problem of two interfering lifting airfoils is reduced to the solution of certain integral equations. It is shown that the solutions of these equations appropriate to (a) direct boundary-value problems (given shape), (b) inverse boundary-value problems (given velocities), and (c) simply mixed boundary-value problems (given either shape or velocity on one airfoil and the converse on the other) conform to the same general velocity formula. This formula consists of a singular part in terms of Theta functions and a Laurent series whose coefficients can be adapted to accommodate (a), (b), or (c) without further recourse to integral equations.
Author: Ishwar C. Bhateley Publisher: ISBN: Category : Languages : en Pages : 379
Book Description
A method has been developed for the analysis of arbitrary multi-element airfoils in viscous flow. The viscous solution is obtained through an inviscid analysis of an equivalent system defined from viscous considerations. An iterative procedure has been formulated to implement this analysis. The inviscid solution is obtained through a distributed singularity method. A finite-difference method is used to determine boundary-layer characteristics. Methods are included to predict laminar-flow bubbles and separation and transition points. The equivalent airfoil is defined for airfoils with attached flow as well as for airfoils with flow separation. The validity of the method is established through comparison of the predicted results with experimental data for several single- and multi-element airfoils. The comparisons show good agreement for lift coefficient and maximum lift coefficient and fair agreement for drag and pitching moment coefficients. Details of the computer program developed to implement this method are described, including input and output details, FORTRAN source deck listing, and a sample problem. (Author).
Author: Giuseppe Volpe Publisher: ISBN: Category : Languages : en Pages : 67
Book Description
This report describes the development of numerical techniques for predicting the flow over two-element airfoil configurations, such as airfoils with a slat or a flap, at transonic speeds and for designing such airfoil systems. The effort was divided in three phases. The first phase involved the development of a method to compute the inviscid flow over these configurations. In the second phase the inviscid code was coupled to a boundary layer calculation program in order to compute the loss in performance due to viscous effects. In the third phase an inverse design code that constructs the airfoil system corresponding to a desired pressure distribution was developed. (Author).
Author: B. Grossman Publisher: ISBN: Category : Languages : en Pages : 51
Book Description
This report describes the development of a method for numerically computing the inviscid transonic flow field over an airfoil with a leading-edge slat or a trailing-edge flap. The approach is to solve the full inviscid irrotational flow equations about two-element airfoil systems. The methodology consists of the development of a suitable computational plane and grid system through the application of a series of conformal mappings. The appropriate set of equations and boundary conditions are derived in terms of a smoothly varying, single-valued reduced potential function through analytic removal of all singularities in the computational domain. A stable and accurate relaxation procedure is established for the numerical solution of the governing equations. The method is applied to a variety of transonic supercritical two-element airfoil configurations. Results are presented depicting the surface pressure distribution, streamline patterns in the physical and computational domain, and Mach number contours. (Author).
Author: Richard M. James
Author: R. M. James
Author: 
Author: Ishwar C. Bhateley
Author: Kasim Biber
Author: Giuseppe Volpe
Author: B. Grossman
Author: 
Author: David A. Caughey
Author: