Turbulence remains an unsolved problem even though we now know how to produce directly, with the help of modern supercomputers, accurate approximations to the equations that govern turbulent flows. The fact that we can predict some turbulence in this limited sense is nevertheless an enormous step towards the goal of full understanding. Direct numerical simulations and large-eddy simulations are these numerical solutions of turbulence, which reproduce with remarkable fidelity the statistical, structural and dynamical properties of physical turbulent and transitional flows. This volume contains selected papers from the First ERCOFTAC Workshop on Direct and Large-Eddy Simulation, which was held at the University of Surrey, Guildford, U.K. from 28--30 March 1994. The variety of flows now accessible to simulation is evident throughout the volume. Not only are many types of internal and external flow represented, including some complex geometries of engineering or geophysical importance, but the dynamically distinct regimes of incompressible and compressible flow, stratified, buoyant and other thermal flows, and chemically reacting flow are all simulated successfully. This book reveals the current state of direct numerical simulation and large-eddy simulation of transitional and turbulent flows, and will be an invaluable reference for all those with an active interest in these techniques.