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In some countries, summer over-heating is a big problem in a building’s energy balance. Ventilated façades are a useful tool when applied to building design, especially in bioclimatic building design. A ventilated façade is a complex, multi-layer structural solution that enables dry installation of the covering elements. The objective of this paper is to quantify of the improvement in the efficiency of the thermal behaviour of buildings when this sort of façade is installed. These improvements are related to the ventilation capacity of the additional structure to the shield mainly for saving...
Computational Fluid Dynamics has been integrated as a key component of missile aerodynamic performance analyses at Lockheed Martin Missiles & Fire Control for many years. Applications are varied, including preliminary aerodynamic databases, identifying component loading, investigating complex flow fields, and assessing safe separation. A discussion of the procedures and tools used is presented, with specific emphasis on STAR-CCM+. Aerodynamic performance predictions from STAR-CCM+ and an in-house code are compared to wind tunnel test data at several Mach numbers for the Joint Common...
A mesh optimization strategy for accurately estimating the drag of a ground vehicle is proposed based on examining the effect of different mesh parameters. The optimized mesh parameters were selected using a Design of Experiments (DoE) method enabling simulations to be carried out in a limited memory environment, and in a timely manner; without compromising the accuracy of results. The study was extended to take into account the effect of model size. A simplified car model at three scales has been investigated and compared with results from the MIRA model wind tunnel. Parameters that lead to...
A detailed theoretical/numerical framework is established to study the mechanical erosion of graphite nozzle materials in solid rocket motors at practical operating conditions. The propellant considered is aluminized AP/HTPB composite propellant. A combined Eulerian-Lagrangian approach is used to treat the multiphase flow inside the motor. The multi-component gas-phase dynamics is modeled using the conservation equations of mass, momentum, and energy in the Eulerian framework. Turbulence closure was achieved using the standard k-epsilon two-equation model. The dispersed phase consisting of...
The present paper covers the work made in order to be able to perform standard deep water IMO manoeuvring simulations based on a combination of computed and measured hydrodynamic input data.Based on a full set of measured PMM data a reduced test matrix was identified and the standard 10-10 and 20-20 zigzag and the 35 turning circle manoeuvres was simulated. Based on the reduced test matrix all the static PMM conditions were computed with the RANS code STAR-CCM+ in order to obtain the hydrodynamic forces and moments. The computed static PMM data was subsequently used to replace the...
Large Eddy Simulation of an incompressible fluid in a straight pipe with a circular cross-section is investigated with a Finite Volume (FV) method based on polyhedral cells, using synthetic turbulence at the inlet. Results of this non-periodic simulation are quite accurate after 2 diameters from the inlet, showing that the structures are self-sustainable. The method is then extended to a flow in a 180˚ U bend pipe with circular cross-section, using an original automatic and boundary-layer-adapting meshing technique. This configuration, or a more convoluted version of it, is often encountered...
Large-eddy simulation (LES) has been performed for an axisymmetric piston-cylinder assembly with and without swirl. For both cases, the LES mean and rms velocity profiles show better agreement with experimental data than profiles obtained using a Reynolds-averaged Navier–Stokes (RANS) approach with a standard k − ε turbulence model. The sum of the resolved and modeled contributions to turbulence kinetic energy (TKE) approaches grid independence for the meshes used in this study. The sensitivity of LES to key numerical and physical model parameters has been investigated. Results are especially...
Stability and ride comfort of high-speed rolling stock are, for reasons of external aerodynamics, dependent on the external design in conjunction with properties of the vehicle dynamics and the design of the infrastructure, herein referring to the confining tunnel walls. It is a fact that some Japanese high-speed trains are quite prone to tail vehicle vibrations only inside tunnels, while (to the authors’ knowledge) other nation’s comparable train systems are not. In this context the current work describes our results of external aerodynamics, calculated with large eddy simulations, about two...
Two low Reynolds (Reτ about 180) and Mach numbers turbulent plane channel flows with one wall heated and one wall cooled at temperature ratios of 1.02 and 3.0 were computed using Large Eddy Simulation (LES). CD-adapco code STAR-CD with second-order finite volume scheme and the classical Smagorinsky subgrid-scale model with Van Driest damping at the walls was used to solve 3D transient problem and determine the motion of large eddies. The effects of the fluid property variations on the structure of wall turbulence were investigated and compared with earlier LES studies of similar problem.

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