Comparative Studies: CFD, Experimental and Analytical Techniques in the Fluids Laboratory

2003 ◽  
Vol 31 (2) ◽  
pp. 150-159 ◽  
Author(s):  
W. A. Bullough ◽  
J. H. Hart ◽  
S. B. Chin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamic Viscosity ◽  
Comparative Studies ◽  
Analytical Techniques ◽  
Open Circuit ◽  
Pressure Recovery ◽  
Wind Tunnels ◽  
Air Density ◽  
Computational Fluid Dynamics Cfd

This task is concerned with the recovery of pressure in a fluid as it flows through various conical diffusers of the same inlet (d) and outlet (D) diameters, but with different included angles (2θ). In particular, it involves comparison of the measured and computational fluid dynamics (CFD) predicted pressure recovery coefficients (PRC) and, for modelling purposes only, illustrating the effect of the choice of boundary conditions, pressure recovery patterns along the diffusers and the use of PreBFC. The fluid is air (density ρ and dynamic viscosity μ); the test rigs available are existing open-circuit wind tunnels.

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.

Two-Dimensional Analysis of Tandem/Staggered Airfoils Using Computational Fluid Dynamics

2005 ◽  
Vol 33 (3) ◽  
pp. 195-207 ◽  
Author(s):  
Z. Husain ◽  
M. Z. Abdullah ◽  
T. C. Yap
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Dimensional Analysis ◽  
Lift Coefficient ◽  
Open Circuit ◽  
Computational Method ◽  
Two Dimensional ◽  
Optimum Position ◽  
Computational Fluid Dynamics Cfd

The two-dimensional analysis, using computational fluid dynamics (CFD), of tandem/staggered arranged airfoils of the canard and wing of an Eagle 150 aircraft and also the aerodynamic tests conducted in an open-circuit wind tunnel are presented in the paper. The wind tunnel tests were carried out at a speed of 38m/s in a test section of size 300 mm (width), 300 mm (height) and 600 mm (length), at Reynolds number 2.25 × 105. The tests were carried out with tandem and staggered placement of the airfoils in order to determine the optimum position of the wing with respect to the canard and also to determine the lift coefficient at various angles of attack. The CFD code FLUENT 5 was used to investigate the aerodynamic performance of a two-dimensional model to validate the wind tunnel results. The flow interaction was studied in the tandem and staggered arrangements in the wind tunnel as well as by the computational method. The k-ε turbulence model gave exceptionally good results.

Semi-Empirical Approach to Predicting Temperatures of a Non-Opaque Surface

2002 ◽  
Author(s):  
Bob Bush ◽  
Shu Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Analytical Techniques ◽  
Harsh Environments ◽  
Total Power ◽  
Computational Fluid Dynamics Cfd ◽  
Energy Equations ◽  
Semi Empirical ◽  
Opaque Surface

The methods used in predicting the thermal profile of a high-pressure mercury arc lamp housed in an electronics enclosure are discussed. These types of enclosures are typically operated in harsh environments. High temperature and low pressure air is typically used to cool the electronics inside. A lamp, which dissipates roughly one half of the total power within the box, must be cooled sufficiently so as to not affect the performance of the circuit cards. Since the majority of the heat being transferred from the lamp’s center arc tube to its surrounding atmosphere (to the lamp housing and then to the circuit cards inside the electronics box) is via radiation, a Computational Fluid Dynamics (CFD) code with a radiation solver was essential to drive the design. Fluent Icepak was chosen as a capable code for electronic box type problems. However, lcepak does not account for radiative transfer through non-opaque surfaces. Since the lamp housing is very transmissive in the infrared at certain wavelengths, the energy equations could not be solved using only analytical techniques. Therefore, tests were conducted that first characterized the thermal performance of the lamp and then predicted the energy that was conducted and absorbed by the glass housing (made up of a reflector and front cover). The remaining power was then assumed to be transmissive in nature. In the computational model, powers were iteratively applied to various locations on the lamp housing until the model matched the empirical results. Once the lamp model was characterized, it could be used to drive the design of any type of enclosure in any type of environment.

Optimization of Air Cooling Ribs for 1.5MW Wind Rotor Based on CFD

2012 ◽  
Vol 479-481 ◽  
pp. 50-54
Author(s):  
Ming Qin ◽  
Ming Wei Ge ◽  
Wen Jiang Shi ◽  
Shan Cai Xiao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Exchange ◽  
External Environment ◽  
Cooling Condition ◽  
Width Ratio ◽  
Air Cooling ◽  
Air Density ◽  
Computational Fluid Dynamics Cfd ◽  
Main Factors

To enhance heat exchange between the rotor and external environment, many ribs are arranged on the cover of the machine. The air cooling condition for 1.5MW wind rotor is evaluated by Computational fluid dynamics(CFD). It is found that the density of the air, the flow velocity and the arrangement of the ribs on the rotor cover is the main factors impacting the air cooling effect of the rotor. Under the same running power, the air cooling condition becomes worse with the decrease of air density and becomes better with the increase of wind speed. To improve the cooling condition of the wind rotor, the arrangement of the ribs on the cover is optimized. The results show that the width ratio of the ribs and channels plays an important role in the heat convection. In all our cases, 0.5 is the best. Considering the manufacture processing, the arrangement of 400 ribs is selected in our optimization.

Efficiency prediction for storage chambers using computational fluid dynamics

1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Particle Tracking ◽  
Critical Value ◽  
Complex Geometries ◽  
Bed Shear Stress ◽  
Breadth Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Flow

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.

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