Application of genetic algorithms to the design of airfoil pressure distributions

NLR participates in the ECARF (European Computation Aerodynamics Research Project) "Optimum Design" project, developing an algorithm for multi-point airfoil design. Within the ECARP project a test case has been defined for two-point design with the aid of well-specified target pressure distributions. It appears that optimization of pressure...

Some longitudinal handling qualities design guidelines for active control technology transport aircraft

This report contains a summary of the main conclusions and recommendations from extensive work performed by the Flight Mechanics Action Group on Handling Qualities (FM/AGOl) of the Group for Aeronautical Research and Technology in Europe (GARTEUR). The work of this Action Group, which involved cooperation between research institutes of France ...

De weg van eisen naar eigenschappen voor informatievoorziening - The transfer of requirements to characteristics of information supply

In the development of information systems the first step is the definition of user requirements. Correctness and completeness of user requirement cannot be guaranteed. A systematic approach following a requirements checklist reduces the risks of errors and omissions considerably. After their definition the requirements are to be translated into...

Accuracy of modal frequency set with fictitious joints modelling

If one wishes to simulate the djmamics of a structurally flexible, mechanical system with the aid of rigid body software, one may be tempted to use the "fictitious joints" modelling technique recently advocated In literature. The technique is believed to be promising in the case of flexible, slender beams, such as some of the links of a space...

Half-model testing in the NLR High-Speed Wind tunnel HST, a 1981 status report

Low-speed handling qualities of advanced transport aircraft; A comparison of ground-based and in-flight simulator experiments

Determination of low-speed longitudinal manoeuvring criteria for transport aircraft with advanced flight control systems

The application of Active Control Technology concepts and in particular the Relaxed Static Stability principle in certain categories of future transport aircraft will lead to the introduction of primary flight control systems incorporating full-time stability augmentation. For this category of transport aircraft adequate handling quality...

Measurements in a 2-D wake and in a 2-D wake merging into boundary layer: Data report

Extensive measurements of mean and fluctuating quantities in a 2-D wake shed from a flat plate and in the flow field of a 2-D wake merging into a boundary layer are described. The 'results are given in tabular and graphical form.

Experimental investigation of the aerodynamic characteristics of a wing propulsion jets

With the intent to test the qualities of the theoretical models used in two different calculation methods, pressure distributions have been measured on a simple half model wing-in-jet combination. The position of the jets relative to the wing was varied, mainly in a plane perpendicular to the span. Jet velocities of 1, 2 and 3 times the tunnel...

The need of stick force stability for attitude-stabilized aircraft. Part II

A description is given of flight tests related to the effect of various levels of (artificial) positive stick force stability on the longitudinal controllability in the landing approach of an attitudestabilized aircraft. Approach performance and pilot commentary of 60 ILS/VASIS approaches flown with a twin-engined jet transport have been...

Exploratory investigation of decelerating approaches of a twin-engined jet transport: Vol. II: Moving-base simulation and comparison with related experiments

Aircraft noise perceived on the ground can be reduced by decelerating the aircraft during the landing approach. As an additional benefit the lower thrust settings existing during a part of the approach and the shorter approach time result in a reduced fuel consumption as compared to a conventional approach. This report deals with an experiment...

The need of stick force stability for attitude-stabilized aircraft. Part 1

After introductory background information on the landing approach piloting task and some arguments for expanding the knowledge on handling quality criteria for certain advanced transport designs, results are given of flight tests related to the effect of positive stick force stability on the longitudinal controllability in the landing approach...

Program for the computation of axisymmetric supersonic flow around launch type vehicles, based on the method of characteristics

In this report a program in ALGOL (CDC-3300, MBOS (3,2) operating system) is described for the computation of the supersonic flow of a thermally and calorically perfect gas around axisymnetric bodies. Computational details are given and some numerical results are presented. Emphasis is placed on the organization of the program. For a specific...

Calculation of unsteady subsonic aerodynamic characteristics by means of the doublet lattice method

A method is desoribed for calculating the aerodynamic loading on nonplanar, infinitely thin, harmonically oscillating airfoils in subsonic flow as originally developed by Albano, Redden, Qiesing and Kalman. The generalized aerodynamic force coefficients are determined from the calculated pressure distributions. Because of the flexibility of the...