Inverse method with geometric constraints for transonic airfoil design

Inverse method with geometric constraints for transonic airfoil design

Fray, J.M.J.
Slooff, J.W.
Boerstoel, J.W.
Kassies, A.

National Aerospace Laboratory NLR

1984-07-03

An engineering method for the design of airfoils having a prescribed pressure distribution in subsonic or transonic flow is described. The method is based on an iterative procedure of "residual-correction" type. In each iteration step, the difference between a current and a target pressure distribution (residual) is determined by a fast (multi-grid) finite-volume full-potential code. Corrections to the geometry driving the pressure residual to zero are determined by a global, inverse, thinairfoil theory based method for the subsonic part of the flow field, and by means of a local, inverse, wavy-wall theory based formula for the supersonic part of the flow field. The determination of the geometry correction has been formulated as a minimization problem in the sense that pressure distribution and geometry requirements may be balanced in a weighted least squares sense. The method is described briefly, including the basic mathematical/physical formulation and the main computational aspects. The capabilities of the method are illustrated by means of examples of airfoil designs.

http://resolver.tudelft.nl/uuid:49be75a6-7935-4957-8959-ae649d87e900

Nationaal Lucht- en Ruimtevaartlaboratorium

Campus only

NLR MP 84069 U

Aerospace Engineering Reports

report

(c)1984 National Aerospace Laboratory NLR