scholarly journals Computational Fluid Dynamics in Solid Earth Sciences–a HPC challenge

2012 ◽  
Vol 22 (7) ◽  
pp. 32-36
Author(s):  
Vlad Constantin Manea ◽  
Marina Manea ◽  
Mihai Pomeran ◽  
Lucian Besutiu ◽  
Luminita Zlagnean

Presently, the Solid Earth Sciences started to move towards implementing High Performance Computational (HPC) research facilities. One of the key tenants of HPC is performance, which strongly depends on the interaction between software and hardware. In this paper, they are presented benchmark results from two HPC systems. Testing a Computational Fluid Dynamics (CFD) code specific for Solid Earth Sciences, the HPC system Horus, based on Gigabit Ethernet, performed reasonably well compared with its counterpart CyberDyn, based on Infiniband QDR fabric. However, the HPCC CyberDyn based on low-latency high-speed QDR network dedicated to MPI traffic outperformed the HPCC Horus. Due to the high-resolution simulations involved in geodynamic research studies, HPC facilities used in Earth Sciences should benefit from larger up-front investment in future systems that are based on high-speed interconnects.

2014 ◽  
Vol 71 (2) ◽  
Author(s):  
Pang Jung Hoe ◽  
Nik Ahmad Ridhwan Nik Mohd

The need for high performance and green aircraft has brought the blended wing (BWB) aircraft concept to the centre of interest for many researchers. BWB is a type of aircraft characterized by a complex blending geometry between fuselage and wing. Recently, many researches had been performed to unlock its aerodynamic complexity that is still not well understood. In this paper, aerodynamic characteristic of a baseline BWB configuration derived from simple conventional aircraft configuration was analysed using the Reynolds-averaged Navier-Stokes computational fluid dynamics (CFD) solver. The main objectives of this work are to predict the aerodynamic characteristics of the BWB concept at steady flight conditions and at various pitch angles. The results obtained are then compared against a simple conventional aircraft configuration (CAC). The results show that the BWB configuration used has 24% higher L/D ratio than the CAC. The increment to the L/D however is mainly due to lower drag than the improvement in the lift. 


2012 ◽  
Vol 220-223 ◽  
pp. 1698-1702
Author(s):  
Jian Chen ◽  
Zhu Ming Su ◽  
Qi Zhou ◽  
Jian Ping Shu

A novel hydraulic rotary high speed on/off valve is investigated. The function of the outlet turbine and the effect on revolution speed of valve spool are analyzed. The inner fluid flow condition under full open case of the on/off valve is simulated using computational fluid dynamics(CFD) method based on Ansys/Fluent and velocity and pressure profiles of fluid inside valve are obtained. Suggestions on optimizing the geometry of valve to decrease transition losses are given.


Joint Rail ◽  
2002 ◽  
Author(s):  
Robert A. MacNeill ◽  
Samuel Holmes ◽  
Harvey S. Lee

This paper describes measurement of the aerodynamic pressures produced by a Bombardier High-Speed Non-Electric Locomotive (HSNEL) on an adjacent stationary double-stack freight car. Static pressures are measured on the near and far-side faces of the freight containers over a range of locomotive speeds from 60 to 130 mph. This data is also compared with the pressures predicted by computational fluid dynamics (CFD) simulations.


2016 ◽  
Vol 842 ◽  
pp. 186-190 ◽  
Author(s):  
Anh Tuan Phan

Hovercraft operates on multi-terrains such as on water surface, on roads, on mud, on non-flat surfaces... it is used popular on the world. With the ability of operating on multi-terrains at high speed, hovercraft is used for many purposes, such as on surveying and rescues missions on areas that are not reachable by normal vehicles, on military missions and traveling... Currently, methods for estimating hovercraft resistance are not accurate enough due to many experiential formulae and coefficients involved during calculating process. This paper presents a method for calculating hovercraft resistance using computational fluid dynamics (CFD) tools. This research method is used popular and modern research method on the world. The method was applied for calculating resistance of a 7 meters length hovercraft model. The modelling results give us suggestions in selecting engine power and operating speeds for minimizing fuel consumption.


Author(s):  
Gil Jun Lee ◽  
Jay Kim ◽  
Tod Steen

Squeeze film dampers (SFDs) are used in high-speed turbomachinery to provide external damping to the system. Computational fluid dynamics (CFD) simulation is a highly effective tool to predict the performance of SFDs and obtain design guidance. It is shown that a moving reference frame (MRF) can be adopted for CFD simulation, which saves computational time significantly. MRF-based CFD analysis is validated, then utilized to design oil plenums of SFDs. Effects of the piston ring clearances, the oil groove, and oil supply ports are studied based on CFD and theoretical solutions. It is shown that oil plenum geometries can significantly affect the performance of the SFD especially when the SFD has a small clearance. The equivalent clearance is proposed as a new concept that enables quick estimation of the effect of oil plenum geometries on the SFD performance. Some design practices that have been adopted in industry are revisited to check their validity. Based on simulation results, a set of general design guidelines is proposed.


Author(s):  
A P Gaylard

The growing application of computational fluid dynamics (CFD) to railway aerodynamics is described. After cautioning against overselling the capabilities of CFD codes, a review is presented of the more significant computational work undertaken in this field. Three recent applications of CFD are examined: (a) a high-speed rail vehicle in a cross-wind; (b) cross-flow impingement on a freight vehicle in the Channel Tunnel; (c) the temperature environment in a stationary passenger train. Comparative experimental data are offered for each of the above. An analysis of these applications is used to derive a promising strategy for the practical application of CFD.


SINERGI ◽  
2018 ◽  
Vol 22 (3) ◽  
pp. 139 ◽  
Author(s):  
Ahmad Fitriadhy ◽  
Nur Amira Adam ◽  
N. Amalina ◽  
S. A. Azmi

Seakeeping is the dynamic response of the ship in waves that may affect to passenger’s uncomfortability due to a harsh environmental condition.  Therefore, an extensive assessment of seakeeping performance in the initial step of ship design is necessarily required. The authors here proposed to analyze the seakeeping performance of ‘deep-V’ high speed catamaran using Computational Fluid Dynamics (CFD) approach. Several effects of Froude number (Fr), wave-length (


2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Jifeng Wang ◽  
Janusz Piechna ◽  
Norbert Müller

A novel manufacturing approach similar to filament winding is able to produce high-performance and lightweight composite wheels. The production can be rapid, inexpensive, and utilize commercially available winding machines. One potential application of the wheel is as a wind turbine. It is widely accepted that placing a duct around a wind turbine can enhance its performance, especially when a new designed turbine with unique advantages has a relatively low power coefficient, it is necessary to examine the benefits and economics of a turbine in a duct. In this study, a numerical analysis of a ducted multiblade composite wind turbine using computational fluid dynamics (CFD) is evaluated and compared with a bare wind turbine of the same turbine area. This investigation was performed using FLUENT in conjunction with the GAMBIT meshing tool. The extracted power is calculated and compared for these two modeling designs. Through the comparison of power coefficient variation with thrust coefficient, it was found that a ducted turbine can be 2–3 times that of the power extracted by a bare turbine. The results of the analysis provide an insight into the aerodynamic design and operation of a ducted wind turbine in order to shorten the design period and improve its technical performance.


Author(s):  
Emre Dikmen ◽  
Peter van der Hoogt ◽  
Andre´ de Boer ◽  
Ronald Aarts ◽  
Ben Jonker

In this study the temperature increase and heat dissipation in the air gap of a cylindrical mini rotor stator system has been analyzed. A simple thermal model based on lumped parameter thermal networks has been developed. With this model the temperature dependent air properties for the fluid-rotor interaction models have been calculated. Next the complete system has also been modeled by using computational fluid dynamics (CFD) with Ansys-CFX and Ansys. The results have been compared and the capability of the thermal networks method to calculate the temperature of the air between the rotor and stator of a high speed micro rotor has been discussed.


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