The focus of QLES is on issues related to assessing, assuring, and predicting the quality of LES. The tendency to apply LES-methodologies to turbulent flow problems of significant complexity, such as arise in various applications in technology and in many natural flows puts this workshop in its timely context. Different error sources in LES are related to subgrid-scale modeling, to numerical discretization techniques, to boundary-condition treatments, etc. To establish the credibility of LES as a tool for the innovation of industrial flow applications and the study of complex-physics problems, a comprehension of the nonlinear error-accumulation arising in large-eddy simulations is required. The QLES2009 workshop is the second workshop in the QLES series. Its predecessor, QLES2007, was organized fom 24-26 October in Leuven, Belgium

QLES2009 invites original contributions which enhance the knowledge on error sources and their interaction in LES, and may lead to criteria for the prediction and optimization of simulation quality. The workshop will concentrate on topics such as:

	mathematical analysis and foundation for subgrid modeling,
	numerical and mathematical analysis of subgrid-scale-model and discretization errors,
	computational error-assessment,
	high-Reynolds number modeling and error-assessment of near-wall flows,
	error assessment in complex applications,
	treatment of boundary conditions, inflow boundaries, generation of artificial turbulence, and related errors.

A connection with benchmark problems studied in the COST Action LES-AID is further pursued. As in QLES2007, QLES2009 provides a platform for the reporting of results. Information for interested contributors is further described in detail on the Info for Authors page.