Emergency crowd simulation for outdoor environments

Cataloged from PDF version of article.We simulate virtual crowds in emergency situations caused by an incident, such as a fire, an explosion, or a terrorist attack. We use a continuum dynamics-based approach to simulate the escaping crowd, which produces more efficient simulations than the agent-based approaches. Only the close proximity of the incident region, which includes the crowd affected by the incident, is simulated. We use a model-based rendering approach where a polygonal mesh is rendered for each agent according to the agent's skeletal motion. To speed up the animation and visualization, we employ an offline occlusion culling technique. We animate and render a pedestrian model only if it is visible according to the static visibility information computed. In the pre-processing stage, the navigable area is decomposed into a grid of cells and the from-region visibility of these cells is computed with the help of hardware occlusion queries. (C) 2009 Elsevier Ltd. All rights reserved

Use of a Viscous Flow Simulation Code for Static Aeroelastic Analysis of a Wing at High-Lift Conditions

In this paper, we present a static aeroelastic analysis of a wind tunnel test model of a wing in high-lift configuration using a viscous flow simulation code. The model wing was tailored to deform during the tests by amounts similar to a composite airliner wing in highlift conditions. This required use of a viscous flow analysis to predict the lift coefficient of the deformed wing accurately. We thus utilized an existing static aeroelastic analysis framework that involves an inviscid flow code (Cart3d) to predict the deformed shape of the wing, then utilized a viscous flow code (Overflow) to compute the aerodynamic loads on the deformed wing. This way, we reduced the cost of flow simulations needed for this analysis while still being able to predict the aerodynamic forces with reasonable accuracy. Our results suggest that the lift of the deformed wing may be higher or lower than that of the non-deformed wing, and the washout deformation of the wing is the key factor that changes the lift of the deformed wing in two distinct ways: while it decreases the lift at low to moderate angles of attack simply by lowering local angles of attack along the span, it increases the lift at high angles of attack by alleviating separation

Implementation of a Body Force Model into OVERFLOW for Propulsor Simulations

No abstract availabl

Implementation of a Body Force Model into OVERFLOW for Propulsor Simulations

No abstract availabl

Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results

Design and Analysis of Dual Pressure Probes for Predicting Turbulence-Induced Vibration in Low Velocity Flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97074/1/AIAA2012-1881.pd

Three Dimensional Microfluidic Cell Arrays for ex Vivo Drug Screening with Mimicked Vascular Flow

Currently, there are no reliable ex vivo models that predict anticancer drug responses in human tumors accurately. A comprehensive method of mimicking a 3D microenvironment to study effects of anticancer drugs on specific cancer types is essential. Here, we report the development of a three-dimensional microfluidic cell array (3D μFCA), which reconstructs a 3D tumor microenvironment with cancer cells and microvascular endothelial cells. To mimic the in vivo spatial relationship between microvessels and nonendothelial cells embedded in extracellular matrix, three polydimethylsiloxane (PDMS) layers were built into this array. The multilayer property of the device enabled the imitation of the drug delivery in a microtissue array with simulated blood circulation. This 3D μFCA system may provide better predictions of drug responses and identification of a suitable treatment for a specific patient if biopsy samples are used. To the pharmaceutical industry, the scaling-up of our 3D μFCA system may offer a novel high throughput screening tool

Mass Taxon-Sampling as a Strategy towards Illuminating the Natural History of Campanula (Campanuloideae)

Speciose clades usually harbor species with a broad spectrum of adaptive strategies and complex distribution patterns, and thus constitute ideal systems to disentangle biotic and abiotic causes underlying species diversification. The delimitation of such study systems to test evolutionary hypotheses is difficult because they often rely on artificial genus concepts as starting points. One of the most prominent examples is the bellflower genus Campanula with some 420 species, but up to 600 species when including all lineages to which Campanula is paraphyletic. We generated a large alignment of petD group II intron sequences to include more than 70% of described species as a reference. By comparison with partial data sets we could then assess the impact of selective taxon sampling strategies on phylogenetic reconstruction and subsequent evolutionary conclusions

The D8 Aircraft: An Aerodynamics Study of Boundary Layer and Wake Ingestion Benefit

No abstract availabl

CFD/CAA Analysis for a Wing Leading Edge Test in the Quiet Flow Facility

No abstract availabl