The numerical experiment in fluid mechanics

Abstract

Several aspects of the use of digital computers to generate solutions of equations of interest to fluid mechanics are discussed. The inter-disciplinary nature of the field of computational fluid dynamics (CFD) is emphasized: the dependence on strides in computer technology, the impact of advances in algorithm development, the continuous interaction with laboratory experiment and analytical theory. The particular role of that mode of computer usage usually referred to as the numerical experiment is highlighted. ‘Experiments’ of this type have played a central role in establishing concepts such as the soliton and the strange attractor as paradigms within fluid mechanics. The ambitious goal of providing digital counterparts to laboratory equipment such as the wind tunnel is considered. The possibility of abandoning the Eulerian representation of flow fields in favour of following swarms of Lagrangian particles on a computer is stressed. Issues arising from and results of using this methodology are reviewed. Computer simulations are contrasted with computer generated animation. The paper concludes with speculations on future developments.