We compare the statistics of driven, supersonic turbulence at high Mach number using FLASH a widely used Eulerian grid-based code and PHANTOM, a Lagrangian smoothed particle hydrodynamics (SPH) code at resolutions of up to 512 in both grid cells and SPH particles. We find excellent agreement between codes on the basic statistical properties: a slope of k in the velocity power spectrum for hydro...

As one of the main aerodynamic noise sources of high-speed trains, the bogie is a complex structure containing many components and the flow around it is extremely dynamic with high-level turbulence. Flow around a simplified bogie at scale 1:10 is studied numerically using Computational Fluid Dynamics (CFD) for comparison with experimental measurements. The upstream inlet flow is represented as ...

A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been complete...

We describe Lagrangian measurements of water droplets in grid generated wind tunnel turbulence at a Taylor Reynolds number of R(lambda)=250 and an average Stokes number (St) of approximately 0.1. The inertial particles are tracked by a high speed camera moving along the side of the tunnel at the mean flow speed. The standardized acceleration probability density functions of the particles have s...

We report the results of the first systematic Lagrangian experimental investigation in a previously unexplored regime of very light (air bubbles in water) and large (D/η 1) particles in turbulence. Using a traversing camera setup and particle tracking, we study the Lagrangian acceleration statistics of ∼3mm diameter (D) bubbles in a water tunnel with nearly homogeneous and isotropic turbulence ...

The Spalart-Allmaras and the Menter SST k-ω turbulence models are shown to have the undesirable characteristic that, for fully turbulent computations, a transition region can occur whose extent varies with grid density. Extremely fine two-dimensional grids over the front portion of an airfoil are used to demonstrate the effect. As the grid density is increased, the laminar region near the nose ...

Financial services providers are exposed to a highly turbulent environment that is characterized by an intense competition for the development of new financial products and the attraction of customers. Against this background, Grid technology assimilation can be assumed to be a potential strategic response to address fast changing market demands and to enhance the operational agility of busines...

Wind powerfluctuations at the turbine and farm scales are generally not expected to be correlated over large distances.When power fromdistributed farms feeds the electrical grid,fluctuations from various farms are expected to smooth out. Using data from the Irish grid as a representative example, we analyze wind power fluctuations entering an electrical grid.We find that not only are grid-scale...

We present results of large-scale three-dimensional simulations of weakly magnetized supersonic turbulence at grid resolutions up to 1024 cells. Our numerical experiments are carried out with the Piecewise Parabolic Method on a Local Stencil and assume an isothermal equation of state. The turbulence is driven by a large-scale isotropic solenoidal force in a periodic computational domain and ful...