Global scientific and engineering simulations on scalar, vector and parallel LCAP-type supercomputers

Abstract
We present here an example of the global simulation approach to complex systems, selecting, as example, the study of a liquid, specifically water. We start by building the molecules of the liquid from nuclei and electrons using quantum mechanics. Next we obtain the interaction potentials (two, three and four body), again by quantum mechanics. Then we use Monte Carlo and molecular dynamics to study the motions of a water molecule within its Onsager sphere, and the collective properties; subsequently we overlap fluid dynamics by considering a flow along a channel with or without obstacles; finally we extend further and report a preliminary simulation of a Benard problem, using Newton’s equations. These simulations are performed on a parallel supercomputer which we have recently assembled; the system is briefly described in the second part of this work. A number of applications in science and engineering are analysed with attention to the degree of parallelization achievable with and without special hardwares such as busses and bulk shared memory. To conclude the implication of the global simulation methodology and supercomputers evolution is discussed in terms of productivity of information.