New CFD Method for Simulation of Slosh & Microgravity Fluid Dynamics

Author(s):  
Robert E. Manning ◽  
Ian Ballinger ◽  
Mack Dowdy
2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sulistiya Sulistiya ◽  
Alief Sadlie Kasman

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.


2021 ◽  
Vol 2053 (1) ◽  
pp. 012013
Author(s):  
N. Abdul Settar ◽  
S. Sarip ◽  
H.M. Kaidi

Abstract Wells turbine is an important component in the oscillating water column (OWC) system. Thus, many researchers tend to improve the performance via experiment or computational fluid dynamics (CFD) simulation, which is cheaper. As the CFD method becomes more popular, the lack of evidence to support the parameters used during the CFD simulation becomes a big issue. This paper aims to review the CFD models applied to the Wells turbine for the OWC system. Journal papers from the past ten years were summarized in brief critique. As a summary, the FLUENT and CFX software are mostly used to simulate the Wells turbine flow problems while SST k-ω turbulence model is the widely used model. A grid independence test is essential when doing CFD simulation. In conclusion, this review paper can show the research gap for CFD simulation and can reduce the time in selecting suitable parameters when involving simulation in the Wells turbine.


2010 ◽  
Vol 4 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Mohammed Zubair ◽  
Vizy Nazira Riazuddin ◽  
Mohammed Zulkifly Abdullah ◽  
Rushdan Ismail ◽  
Ibrahim Lutfi Shuaib ◽  
...  

Abstract Background: It is of clinical importance to examine the nasal cavity pre-operatively on surgical treatments. However, there is no simple and easy way to measure airflow in the nasal cavity. Objectives: Visualize the flow features inside the nasal cavity using computational fluid dynamics (CFD) method, and study the effect of different breathing rates on nasal function. Method: A three-dimensional nasal cavity model was reconstructed based on computed tomographic images of a healthy Malaysian adult nose. Navier-Stokes and continuity equations for steady airflow were solved numerically to examine the inspiratory nasal flow. Results: The flow resistance obtained varied from 0.026 to 0.124 Pa.s/mL at flow-rate from 7.5 L/min to 40 L/min. Flow rates by breathing had significant influence on airflow velocity and wall shear-stress in the vestibule and nasal valve region. Conclusion: Airflow simulations based on CFD is most useful for better understanding of flow phenomenon inside the nasal cavity.


Author(s):  
Yohsuke Imai ◽  
Takahito Miki ◽  
Masanori Nakamura ◽  
Takuji Ishikawa ◽  
Shigeo Wada ◽  
...  

Chronic Obstructive Pulmonary Disease (COPD) refers to a group of diseases that are characterized by airflow obstruction. Currently, COPD is the fourth leading cause of death worldwide, but fluid dynamics in airways of COPD patients has not been well understood. Multi-slice Computer Tomography (CT) images provide three-dimensional realistic geometry of patient airways. Computational Fluid Dynamics (CFD) analysis using the patient-specific geometry will greatly help the understanding of the mechanism of COPD. However, few studies have performed such a patient-specific pulmonary airflow simulation. Our aim is to develop a patient-specific CFD method applicable to multi-scale airways, involving trachea, bronchi, bronchioles, and alveoli. We propose a CFD method using multi-level voxel modeling of airway geometry, in which voxel size in a local domain is adaptively refined or coarsened to the local flow scale.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3350 ◽  
Author(s):  
Guoping Huang ◽  
Xin Xiang ◽  
Chen Xia ◽  
Weiyu Lu ◽  
Lei Li

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.


2012 ◽  
Vol 516-517 ◽  
pp. 1074-1077
Author(s):  
Xue Feng Zhao ◽  
Li Min He ◽  
Li Xin Zhao ◽  
Sheng Zhong ◽  
Yang Wang

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.


2010 ◽  
Vol 160-162 ◽  
pp. 280-286
Author(s):  
Ri Chao Liu ◽  
Zhong Hua Tang ◽  
Wei Yang Qi

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.


2013 ◽  
Vol 61 (1) ◽  
pp. 155-160 ◽  
Author(s):  
G. Sztarbała

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


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