Clebsch variable model for unsteady inviscid transonic flow with strong shock waves

In comparison with Euler methods unsteady inviscid transonic full potential methods are known to suffer from limitations with respect to the modeling of shock waves. In this paper unsteady 2D and 3D full potential methods are extended with the Clebsch variable model. This model represents exactly the shockgenerated entropy and vorticity. The...

Hyperbolic grid generation with BEM source terms

A method is presented for the generation of 0-type grids about transverse cross-sections of transport type aircraft. The method combines a hyperbolic grid generation scheme with source terms obtained with a boundary element method in such a way that 0-type grids around fairly complex shapes with concavities can be generated easily. The...

CAR 88: A method to calculate subsonic and supersonic, steady and unsteady, potential flow about complex configurations

A description is given of the method CAR88 for the calculation of steady and time-linearized unsteady subsonic and supersonic flow about complex 2-D and 3-D configurations. The method belongs to the category of the socalled panel methods. Results of applications in supersonic flow are shown which have been made to a 2-D oscillating flat plate, a...

Unsteady transonic flow computations for a rectangular supercritical wing

Results of 3-D steady and unsteady transonic flow calculations for a rectangular supercritical wing are presented which have been obtained from NLR's numerical method FTRAN3 for the solution of the unsteady full potential equation.

ARSPNSC: A method to calculate subsonic steady and unsteady potential flow about complex configurations

A new method ARSPSC is described for the calculation of steady and time-linearized unsteady subsonic potential flow about complex 2-D and 3-D configurations. The method belongs to the category of the so-called panel methods. Applications have been made to a 2-D oscillating flat plate, a 2-D multi-component airfoil with oscillating flap and a 3-D...

Calculation of 2-D unsteady transonic full potential flow about oscillating airfoils by two complementary appraches

Results of 2-D unsteady transonic flow calculations for AGARD standard aeroelastic configurations are presented, which have been obtained from NLR's numerical methods for the solution of the unsteady full potential equation. Two complementary methods have been applied to oscillating transonic flow about thick blunt-nosed airfoils: 1) the time...

ARSPNS: a method to calculate steady and unsteady potential flow about fixed and rotating lifting and nonlifting bodies

A new method ARNSPNS is described for the calculation of steady and time-linearized unsteady incompressible potential flow about arbitrary lifting and nonlifting bodies in an arbitrary mean steady flow field, including rotation. The method belongs to the category of the so-called panel methods. Applications have been made to wind turbines...

How to make your aerodynamics in flutter calculations cheaper

Application of time-linearized methods to oscillating wings in transonic flow and flutter

Unsteady aerodynamic loads in the transonic domain have been obtained with time-linearized methods in which a so-called field panel method is embedded which accounts for a proper radiation of signals towards infinity. The methods are used to predict the unsteady loads and first harmonic pressure distributions on an airfoil and a transport type...

Application of NLR's numerical simulation methods to the transonic potential flow about oscillating wings

unsteady and quasi-steady aerodynamic loads in the transonic flow domain have been obtained from NLR's numerical simulation methods for transonic potential flow. The unsteady results have been obtained with the time-linearized finite volume method FTRAN3, embedding a so-called field panel method which accounts for proper radiation of signals...

A hybrid field panel/finite difference method for 3-D potential unsteady transonic flow calculations

A hybrid method is described for calculating "time-linearized" transonic potential flows. The method combines the advantages of finite difference and integral methods in such a way that computation times are reduced to a level acceptable for routine flutter applications. The corresponding computer code is named FTRAN3. Results of three...

Ontwikkeling van een rekenmethode voor instationaire transsone luchtkrachten op dikke profielen

A field panel method for the calculation of inviscid transonic flow about thin oscillating airfoils with shocks

A method is described for the calculation of two-dimensional unsteady inviscid transonic flow about thin airfoils, including shock waves. This method, a so-called field panel method, is based on the solution of an integral equation which combines a subsonic lifting surface panel method with subsonic source panels in the flow. These source panels...

Calculation of unsteady transonic flows with shocks by field panel methods

A field panel method, FTRAN2, is presented for the calculation of twodimensional inviscid transonic flow including shock waves about an oscillating wing. For a NACA 6UAOO6 and a NACA 6UA010 airfoil results are presented and compared with results of finite difference methods. The good agreement obtained and the lower computer cost shows the...

An improved potential gradient method to calculate airloads on oscillating supersonic interfering surfaces

A description is given of a computationally inqjroved potential gradient method to calculate unsteady aerodynamic derivatives in supersonic flow. Results are presented and comparisons are made with results of existing methods and with experimental data for a fighter-type wing.

A panel method to determine loads on oscillating airfoils in transonic flow with embedded shock waves

A 2-D method is described which combines supersonic and subsonic linear lifting surface theories, both based on the velocity potential panel ajproach, while at the same time the effect of the moving shock is taken into account. For a NACA 64A006 airfoil transonic results are presented in comparison with results of an improved version of the...