Three different cyclist positions were evaluated with Computational Fluid Dynamics (CFD) and wind-tunnel experiments were used to provide reliable data to evaluate the accuracy of the CFD simulations. Specific features of this study are: (1) both steady Reynolds-averaged Navier-Stokes (RANS) and unsteady flow modelling, with more advanced turbulence modelling techniques (Large-Eddy Simulation -...

This paper discusses routing aspects associated with the transition from IPv4 to IPv6. The approach outlined here is designed to be compatible with the Simple Internet Transition (SIT) mechanism. The proposals contained in this document are the opinions of the authors, and have not yet been discussed in detail by the working group. This document is intended as input to the IPNG, Tacit, and Ngtr...

Aeolian processes occur throughout the Solar System and likely on extrasolar planets as well. Models based on data collected in boundary layer wind tunnels have contributed to understanding the physics of these processes. Planetary wind tunnels allow simulation of conditions (atmospheric pressure, density, or kinematic viscosity) on extraterrestrial bodies, and their use over several decades ha...

Emergency smoke ventilation for a uni-directional traffic road tunnel is studied using a CFD modelling approach. Fire scenarios in an uphill ramp for congested traffic conditions have been considered. Based on a longitudinal smoke ventilation system with a damper smoke-extraction device on the ceiling soffit, the impact of longitudinal ventilation (LV) control, operation of fire suppression int...

Results are presented from wind tunnel simulations of gaseous pollutant dispersion in the atmospheric convective boundary layer (CBL) capped by a temperature inversion. The experiments were performed in the thermally stratified wind tunnel of the University of Karlsruhe, Germany. In the tunnel, the case of horizontally evolving, sheared CBL is reproduced. This distinguishes the employed experim...

This paper discusses the possibilities of laboratory simulation of large-scale flow around dunes, both with and without saltation, and the study of the physics of the small-scale particle motion occurring on a sand surface composed of like-moveable particles. Physics of the atmospheric boundary layer are presented in the context of laboratory applications. The governing equations of fluid and/o...

The study of the effect of obstacles on flow and dispersion in the atmospheric boundary layer is one of the most important topics in atmospheric dispersion research. Computational Fluid Dynamics (CFD) methods are increasingly used to predict concentration fields near buildings in an operational context, but extensive validations are still needed. In this paper, we analyse the effect on flow and...