Effects of low bond number liquid motions on spacecraft attitude

The Introduction gives a short review of the effects that onboard liquid may have on the dynamics of the spacecraft. A distinction Is made between arbitrarily moving craft and spin-stabilized vehicles. The modelling of rotating liquid behaviour is very complicated and generally allows only to make predictions on the stability behaviour of a...

SAMID, an interactive system for aircraft drag minimization studies. Mathematical models and methods

An interactive computer program system has been developed that can be used in aircraft drag minimization studies. It comprises algorithms for choosing the spanwise distributions of lift, pitching moment, chord and thicknessto-chord ratio of lifting elements. The choices are optimal in that they minimize induced plus viscous drag while satisfying...

A perspective of mathematical simulation and optimization techniques in computer aided design

The central issue discussed in this paper is how a designer may profit from the use of mathematical simulation and optimization techniques. These techniques can be useful tools to support the designer in solving his design problem. The place and the potential of these techniques in the design process, as well as their use by the designer, are...

Simulation and optimization techniques in computer aided design

The use of numerical simulation and optimization techniques is rapidly expanding in all fields of engineering design. The place and the potential of these techniques in the design process, as well as their use by the designer, are discussed. The principles underlying these techniques are outlined and an overall view is given of the various...

Het gebruik van wiskundige optimalisatietechnieken door ontwerpers?

Wiskundige optimalisatietechnieken kunnen de ontwerper ondersteunen bij de formulering en de oplossing van zijn ontwerpprobleem. Het gebruik van deze technieken breidt zich snel uit over de verschillende technische toepassingsgebieden. De plaats en de mogelijkheden van wiskundige optimalisatietechnieken in het ontwerpproces, alsmede het gebruik...

Optimization in design processes; an informatics point of view

The purpose of this paper is to outline the optimization-system development at NLR. The paper starts with a discussion on the potential of mathematical optimization techniques in aeronautical engineering. Subsequently, the main requirements to be met by a general-purpose optimization system are given. Following this, the implementation at NLR is...

De invloed van CAD op research

NLR has developed an infrastructure of hardware and software for support of aerodynamic design of aircraft. Organizational and technical aspects of this development are described.

CAD-systemen voor overdracht van kennis

The NLR in the Netherlands renders scientific support and technical assistance for the design and operation of aircraft and spacecraft. The approach of NLR can be characterized by integration of experimental and theoretical investigations. For this an integrated computer and terminal network has been developed that links both NLR laboratory...

SAMID: An interactive System for the Analysis and Constrained Minimization of Induced Drag of aircraft configurations

An interactive computer program system has been developed which provides induced-drag analysis, optimization and configuration-design capabilities. The program system employs subsonic far-field (Trefftzplane) analysis, and novel mathematical formulations of the constrained optimization problems which are based on calculus of variations. The...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft Part I: Theory and simulation results

This document presents an approach to sampled data, on-board estimation and control of the attitude motion of manoeuvring spacecraft. Algorithms which are developed include: a - model following control of attitude manoeuvres b - estimation of spacecraft state (attitude, angular velocity, disturbance torque) c - optical-inertial attitude...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft Part II: Simulation software description

This document describes two computer programs developed during a study of the application of modern control techniques in the area of spacecraft attitude control. Theory and simulation results are described in part I of this report. In part II a general overview of the tasks of the simulation program is presented, and program design aspects are...

Application of model following control and estimation techniques to attitude control of manoeuvring spacecraft

The paper presents an approach to sampled data, on-board estimation and control of the attitude motion of manoeuvring spacecraft. Algorithms for (1) estimation of gyroscope parameters (drift rate bias, scale factor error) and spacecraft state (attitude, angular velocity, disturbance torque), and (2) model following control of attitude manoeuvres...