Application of a Diverging-Converging Duct to a FSAE Radiator System

The focus of this paper is the design process for the radiator ducting on the WashU Formula Society of Automotive Engineers racing team vehicle. The side-pods for the WUFR-19 vehicle are designed as a diverging-converging duct around the radiator in order to provide a sufficient mass flow rate through the heat exchanger to cool the engine, while minimizing drag on the vehicle. Internal computational fluid dynamics simulations are run in ANSYS Fluent on an individual channel of the radiator core. A parametric setup is used to iterate through multiple inlet conditions. The goal of these simulations is to determine the relationship between the ducting inlet size, ram pressure and mass flow rate through the radiator core, while also accounting for heat transfer from the radiator in airflow conditions. The usage of internal simulations with varying inlet conditions reduces simulation time when compared to external side-pod simulations that have higher computational requirements and would require geometry modification between simulations. Results show that reducing the inlet size increases the pressure drop across and mass flow rate through the radiator for inlet sizes above 80% of the cross-sectional area of the radiator. Smaller inlet sizes begin to restrict airflow causing the mass flow rate to decrease. An inlet size of 70% of the cross-sectional area of the radiator and an outlet size of 80% of the inlet size were implemented in order to fully cool the engine and minimize drag on the vehicle

Aerothermodynamic Analysis of a Reentry Brazilian Satellite

This work deals with a computational investigation on the small ballistic reentry Brazilian vehicle SARA (acronyms for SAt\'elite de Reentrada Atmosf\'erica). Hypersonic flows over the vehicle SARA at zero-degree angle of attack in a chemical equilibrium and thermal non-equilibrium are modeled by the Direct Simulation Monte Carlo (DSMC) method, which has become the main technique for studying complex multidimensional rarefied flows, and that properly accounts for the non-equilibrium aspects of the flows. The emphasis of this paper is to examine the behavior of the primary properties during the high altitude portion of SARA reentry. In this way, velocity, density, pressure and temperature field are investigated for altitudes of 100, 95, 90, 85 and 80 km. In addition, comparisons based on geometry are made between axisymmetric and planar two-dimensional configurations. Some significant differences between these configurations were noted on the flowfield structure in the reentry trajectory. The analysis showed that the flow disturbances have different influence on velocity, density, pressure and temperature along the stagnation streamline ahead of the capsule nose. It was found that the stagnation region is a thermally stressed zone. It was also found that the stagnation region is a zone of strong compression, high wall pressure. Wall pressure distributions are compared with those of available experimental data and good agreement is found along the spherical nose for the altitude range investigated.Comment: The paper will be published in Vol. 42 of the Brazilian Journal of Physic

Update on Prevalence of Periodontitis in Adults in the United States: NHANES 2009 to 2012

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141963/1/jper0611.pd

Plume Impingement Analysis for the European Service Module Propulsion System

Plume impingement analyses were performed for the European Service Module (ESM) propulsion system Orbital Maneuvering System engine (OMS-E), auxiliary engines, and reaction control system (RCS) engines. The heat flux from plume impingement on the solar arrays and other surfaces are evaluated. This information is used to provide inputs for the ESM thermal analyses and help determine the optimal configuration for the RCS engines

Update on Prevalence of Periodontitis in Adults in the United States: NHANES 2009 to 2012

This report describes prevalence, severity, and extent of periodontitis in the US adult population using combined data from the 2009–2010 and 2011–2012 cycles of the National Health and Nutrition Examination Survey (NHANES)

Creative teaching and learning: towards a common discourse and practice

There has recently been a call for more pedagogic comparative research to counter the dominance of structural and policy led studies. At the same time there is also a necessity to provide alternative comparative research to that concerned with global standardising performance and performativity strategies. The research, on which this paper is based, fulfils both these aims by investigating creative teaching and learning in nine European countries at classroom level using ethnographic methods in a small number of sites for each partner. The research partners share a common discourse of pedagogy that we are calling creative teaching and learning, a common humanitarian discourse and the ethnographic methodology for the research was a strong framework to counter differing cultural approaches to research. The article analytically characterises some significant strategies used by teachers, the creative learning experienced and the meaning that the experiences had for the students involved. We conclude that this research has laid the basis for a common discourse for further research in a comparative approach that will investigate commonalities to build an understanding of international creative pedagogy and investigate differences to enhance the conceptualisation of it

dsmcFoam+: An OpenFOAM based direct simulation Monte Carlo solver

dsmcFoam+ is a direct simulation Monte Carlo (DSMC) solver for rarefied gas dynamics, implemented within the OpenFOAM software framework, and parallelised with MPI. It is open-source and released under the GNU General Public License in a publicly available software repository that includes detailed documentation and tutorial DSMC gas flow cases. This release of the code includes many features not found in standard dsmcFoam, such as molecular vibrational and electronic energy modes, chemical reactions, and subsonic pressure boundary conditions. Since dsmcFoam+ is designed entirely within OpenFOAM’s C++ object-oriented framework, it benefits from a number of key features: the code emphasises extensibility and flexibility so it is aimed first and foremost as a research tool for DSMC, allowing new models and test cases to be developed and tested rapidly. All DSMC cases are as straightforward as setting up any standard OpenFOAM case, as dsmcFoam+ relies upon the standard OpenFOAM dictionary based directory structure. This ensures that useful pre- and post-processing capabilities provided by OpenFOAM remain available even though the fully Lagrangian nature of a DSMC simulation is not typical of most OpenFOAM applications. We show that dsmcFoam+ compares well to other well-known DSMC codes and to analytical solutions in terms of benchmark results

Benchmark numerical simulations of rarefied non-reacting gas flows using an open-source DSMC code

Validation and verification represent an important element in the development of a computational code. The aim is establish both confidence in the algorithm and its suitability for the intended purpose. In this paper, a direct simulation Monte Carlo solver, called dsmcFoam, is carefully investigated for its ability to solve low and high speed non-reacting gas flows in simple and complex geometries. The test cases are: flow over sharp and truncated flat plates, the Mars Pathfinder probe, a micro-channel with heated internal steps, and a simple micro-channel. For all the cases investigated, dsmcFoam demonstrates very good agreement with experimental and numerical data available in the literature