Analysis and Simulation of Air Drag in Vehicles Close-Following

2012 ◽  
Vol 152-154 ◽  
pp. 1438-1442
Author(s):  
Juan Zhang ◽  
Zuo Jun Li ◽  
Bin Bai ◽  
Lei Zhang
Keyword(s):  
Fluid Dynamics ◽  
Turbulence Models ◽  
Far Field ◽  
Air Drag ◽  
Close Spacing ◽  
Research Institutes ◽  
The Standard Model ◽  
Calculation Results ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Vehicles drag reductions arising from close spacing are studied and verified by some research institutes. But this solution was queried by an experiment carried in RMIT University in 2006. Based on two standard Ahmed Bodies, Computational Fluid Dynamics(CFD) method is used to study this problem in this paper. The calculation results by comparing four different CFD turbulence models show that the drag coefficient of the rear car is more than the lead car, and even more than the isolated car when the space of these two cars is less than one time of car length. Furthermore, the calculate results of these four turbulence models show that the standard model is the best model to simulate this problem, and different far field condition will influence the calculate results much more. Therefore, the research of this paper verifies that drag reductions from close spacing still need to be studied.

scholarly journals Validasi Model Turbulensi pada Simulasi Numerik Menggunakan Software Fluent dengan Sayap Onera M6

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sulistiya Sulistiya ◽  
Alief Sadlie Kasman
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computational Result ◽  
Computational Simulation ◽  
Turbulence Models ◽  
Wind Tunnels ◽  
Direct Testing ◽  
The World ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

AbstractNumerical simulation using Computational Fluid Dynamics (CFD) method is one way of predicting airflow characteristics on the model. This method is widely used because it is relatively inexpensive and faster in getting desired results compared with performing direct testing. The correctness of a computational simulation output is highly dependent on the input and how it was processed. In this paper, simulation is done on Onera M6 Wing, to investigate the effect of a turbulence model’s application on the accuracy of the computational result. The choice of Onera M6 Wing as a simulation’s model is due to its extensive database of testing results from various wind tunnels in the world. Among Turbulence models used are Spalart-Allmaras, K-Epsilon, K-Omega, and SST.Keywords: CFD, fluent, Model, Turbulence, Onera M6, Spalart-Allmaras, K-Epsilon, K-Omega, SST.AbstraksSimulasi numerik dengan menggunakan metode Computational Fluid Dynamics (CFD) merupakan salah satu cara untuk memprediksi karakteristik suatu aliran udara yang terjadi pada model. Metode ini banyak digunakan karena sifatnya yang relatif murah dan cepat untuk mendapatkan hasil dibandingkan dengan melakukan pengujian langsung. Benar tidak hasil sebuah simulasi komputasi sangat tergantung pada inputan yang diberikan serta cara memproses data inputan tersebut. Pada tulisan ini dilakukan simulasi dengan menggunakan sayap onera M6 dengan tujuan untuk mengetahui pengaruh penggunaan model turbulensi terhadap keakuratan hasil komputasi. Pilihan sayap onera M6 sebagai model simulasi dikarenakan model tersebut sudah memiliki database hasil pengujian yang cukup lengkap dan sudah divalidasi dari berbagai terowongan angin di dunia. Model turbulensi yang digunakan diantaranya Spalart-Allmaras, K-Epsilon, K-Omega dan SST.Kata Kunci : CFD, fluent, Model, Turbulensi, Onera M6, Spalart-Allmaras, K-Epsilon, K-Omega, SST.

scholarly journals Feasible Concept of an Air-Driven Fan with a Tip Turbine for a High-Bypass Propulsion System

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3350 ◽  
Author(s):  
Guoping Huang ◽  
Xin Xiang ◽  
Chen Xia ◽  
Weiyu Lu ◽  
Lei Li
Keyword(s):  
Fluid Dynamics ◽  
Carbon Dioxide Emissions ◽  
Three Dimensional ◽  
Propulsion System ◽  
Navier Stokes ◽  
Three Dimensional Flow ◽  
Low Pressure Turbine ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Bypass Ratio

The reduction in specific fuel consumption (SFC) is crucial for small/mid-size cost-controllable aircraft, which is very conducive to reducing cost and carbon dioxide emissions. To decrease the SFC, increasing the bypass ratio (BPR) is an important way. Conventional high-BPR engines have several limitations, especially the conflicting spool-speed requirements of a fan and a low-pressure turbine. This research proposes an air-driven fan with a tip turbine (ADFTT) as a potential device for a high-bypass propulsion system. Moreover, a possible application of this ADFTT is introduced. Thermodynamic analysis results show that an ADFTT can improve thrust from a prototype turbofan. As a demonstration, we selected a typical small-thrust turbofan as the prototype and applied the ADFTT concept to improve this model. Three-dimensional flow fields were numerically simulated through a Reynolds averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) method. The performance of this ADFTT has the possibility of amplifying the BPR more than four times and increasing the thrust by approximately 84% in comparison with the prototype turbofan.

Simulation Study of a Porous Overflow-Pipe (POP) Type Hydrocyclone

2012 ◽  
Vol 516-517 ◽  
pp. 1074-1077
Author(s):  
Xue Feng Zhao ◽  
Li Min He ◽  
Li Xin Zhao ◽  
Sheng Zhong ◽  
Yang Wang
Keyword(s):  
Fluid Dynamics ◽  
Oil Content ◽  
Original Structure ◽  
Pipe Length ◽  
Separation Effect ◽  
Overflow Pipe ◽  
New Type ◽  
Fluent Software ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Based on computational fluid dynamics (CFD) method, applying FLUENT software, taking a de-oil hydrocyclone as an original structure, the effect of porous overflow pipe on the performance and pressure characteristics is analyzed. Effect of overflow-pipe length and diameter of the porous overflow-pipe (POP) hydrocyclone is studied. It is found that the extension of overflow-pipe length can play a coalescent role; the new type hydrocyclone can increase oil content around overflow outlet so as to be beneficial for the enhancement of separation effect.

Numerical Simulation of Campus Wind Environment

2010 ◽  
Vol 160-162 ◽  
pp. 280-286
Author(s):  
Ri Chao Liu ◽  
Zhong Hua Tang ◽  
Wei Yang Qi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Pressure Field ◽  
Field Analysis ◽  
Wind Environment ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Rng Turbulence Model

This paper adopted computational fluid dynamics (CFD) method, used k-ε RNG turbulence model-closed control differential equations for numerical simulation. Through numerical simulation and analysis of wind environment in a middle school campus, the round wind field under dominant wind direction was got in the summer and winter. According to the results of velocity field and pressure field, analysis the wind environment, compared the influence of wind direction and surrounding buildings space to the natural ventilation, provided guidance introduce for the layout of the school.

scholarly journals An estimation of conditions inside construction works during a fire with the use of Computational Fluid Dynamics

2013 ◽  
Vol 61 (1) ◽  
pp. 155-160 ◽  
Author(s):  
G. Sztarbała
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Process ◽  
Fire Safety ◽  
Internal Environment ◽  
Preliminary Stage ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Construction Works

Abstract The aim of this paper is to present the application of Computational Fluid Dynamics (CFD) to the assessment of conditions inside construction works during a fire. The CFD method is now commonly used to support the design process of fire safety in construction works. This method is very useful at the preliminary stage of design because it is possible to check the internal environment during a fire and evaluate whether requirements of fire safety are met

Analysis and Simulation of Inner Flow Condition of a Novel Rotary on/off Valve

2012 ◽  
Vol 220-223 ◽  
pp. 1698-1702
Author(s):  
Jian Chen ◽  
Zhu Ming Su ◽  
Qi Zhou ◽  
Jian Ping Shu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Condition ◽  
High Speed ◽  
Ansys Fluent ◽  
Revolution Speed ◽  
Pressure Profiles ◽  
Open Case ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

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.

Application of CFD to evaluate the pore morphology effect on nanofluid flooding for enhanced oil recovery

RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 28938-28949 ◽  
Author(s):  
Reza Gharibshahi ◽  
Arezou Jafari ◽  
Ali Haghtalab ◽  
Mohammad Saber Karambeigi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Recovery Factor ◽  
Pore Morphology ◽  
Morphology Effect ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

In this study a computational fluid dynamics (CFD) method has been developed to simulate the effect of pore morphology and its distribution in a 2D micromodel on the enhanced oil recovery factor of nanofluid flooding.

Numerical Investigation of Dusts Removal from Tramway Surface by Street Vacuum Sweeper

2011 ◽  
Vol 236-238 ◽  
pp. 1619-1622 ◽  
Author(s):  
Bo Fu Wu ◽  
Jin Lai Men ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
Pressure Drops ◽  
Operational Safety ◽  
Airflow Field ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

In order to enhance the operational safety of tram vehicle and reduce the wear of guide wheels mounted on the vehicle, it is necessary to remove particles such as dusts and silts from tramway surface. The aim of this paper is to evaluate the effectiveness of street vacuum sweeper for sucking up dusts from tramway surface. A numerical model was developed based on dusts removal process. Under different pressure drops across the pickup head of the street vacuum sweeper, the flow field and dusts removal efficiency were analyzed with computational fluid dynamics (CFD) method. The numerical results show that a higher pressure drop can improve the airflow field in the pickup head and results in higher dusts removal efficiency, but higher pressure drop definitely need more energy. Therefore, a balance should be taken into consideration.

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