Heat flow analysis of an FPSO topside model with wind effect taken into account: A wind-tunnel test and CFD simulation

2011 ◽  
Vol 38 (10) ◽  
pp. 1130-1140 ◽  
Author(s):  
B.J. Kim ◽  
J.Y. Yoon ◽  
G.C. Yu ◽  
H.S. Ryu ◽  
Y.C. Ha ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Heat Flow ◽  
Cfd Simulation ◽  
Flow Analysis ◽  
Wind Tunnel Test ◽  
Wind Effect

Current Drag From Tow and Wind Tunnel Tests of a FLNG Hull

2016 ◽  
Author(s):  
Zhenjia (Jerry) Huang ◽  
Jang Kim ◽  
Hyunchul Jang ◽  
Scott T. Slocum
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Model Test ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Model Tests ◽  
Additional Contribution ◽  
Wind Tunnel Model ◽  
Tunnel Model ◽  
Current Drag

In this paper, the current drag of a barge-shaped floating liquefied natural gas (FLNG) vessel was studied. Three model tests were performed — a wind tunnel model test, a submerged double-body tow test and a surface tow test. Computational fluid dynamics (CFD) simulations were carried out to gain further insights into the test results. During testing, the tow speed was kept low to avoid surface waves. When the current heading was around the beam current direction, the transverse drag coefficient measured from the wind tunnel test was significantly lower than those of the submerged tow and surface tow tests. The submerged tow and the surface tow provided similar drag coefficients. Results presented in this paper indicated that the difference between the wind tunnel test and the tow tests was caused by the wind tunnel boundary layer effect on the incoming wind profile and formation of a recirculation zone on the upstream side of the model, with a possible additional contribution from the wind tunnel floor constraint on the flow in the wake. Such effects are not accounted for with the simple corrections based on flow velocity reduction in the wind tunnel boundary layer. When conducting future wind tunnel model tests for barge-shaped FLNG hulls, one should consider the potential under-measurement of the transverse drag. In this paper, details of the FLNG model, test setup, test quality assurance (QA), measurement and CFD simulation results are presented, as well as discussions and recommendations for model testing.

scholarly journals Numerical CFD Simulation and Test Correlation in a Flight Project Environment

2015 ◽  
Author(s):  
K. K. Gupta ◽  
S. F. Lung ◽  
A. H. Ibrahim
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Flight Testing ◽  
Project Environment ◽  
Test Correlation

This paper presents detailed description of a novel CFD procedure and comparison of its solution results to that obtained by other available CFD codes as well as actual flight and wind tunnel test data pertaining to the GIII aircraft, currently undergoing flight testing at AFRC.

Feasibility investigation of large-scale model suspended by cable-driven parallel robot in hypersonic wind tunnel test

2016 ◽  
Vol 231 (13) ◽  
pp. 2375-2383 ◽  
Author(s):  
Xiaoguang Wang ◽  
Miaojiao Peng ◽  
Zhenghong Hu ◽  
Yueshi Chen ◽  
Qi Lin
Keyword(s):  
Wind Tunnel ◽  
Large Scale ◽  
Cfd Simulation ◽  
Aerodynamic Force ◽  
Wind Tunnel Test ◽  
Special Kind ◽  
Parallel Robot ◽  
Scale Model ◽  
Hypersonic Wind Tunnel ◽  
Large Scale Model

Cable-driven parallel robot is a special kind of robot, which is actuated by cables. It is already applied in the low speed wind tunnel to get aerodynamic measurement of aircraft model, and the aircraft pose could be adjusted by changing the cable length. Whether it can be used in hypersonic wind tunnel still needs further discussion. This paper presents the dynamics and aerodynamics analysis of a large-scale model supported by 6-DOF cable-driven parallel robot to investigate the feasibility of this special kind of suspension system in hypersonic wind tunnel. The description of this setup with a X-51A-like model is given, and then based on the system dynamic equations, aerodynamic force and stiffness matrix are derived. In the simulation, properties of dynamics and aerodynamics are mainly concerned. A typical shock tunnel with flow duration of about 100 milliseconds is taken as an example, and results show that the system is stable enough to meet the fundamental static wind tunnel test. From the cable tension variation under impact load and the sensitivity analysis, it is likely accessible to derive the aerodynamic forces. Compared with the sting suspension method, cable-driven parallel robot has the priority of higher inherent frequency and more flexible degrees. The interference to the flow field induced by cables is also preliminarily proved to be small by the CFD simulation, which can be acceptable and corrected. Researches conducted show the feasibility of cable-driven parallel robot’s application in hypersonic wind tunnel.

Study on Static Wind Loading Coefficients of Suspension Bridge Based on CFD Simulation and Wind Tunnel Test

2011 ◽  
Vol 66-68 ◽  
pp. 334-339
Author(s):  
Mei Yu ◽  
Hai Li Liao ◽  
Ming Shui Li ◽  
Cun Ming Ma ◽  
Nan Luo ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Wind Load ◽  
Dynamics Simulation ◽  
Wind Loading ◽  
Suspension Bridges ◽  
Long Span ◽  
Section Model

Long-span suspension bridges, due to their flexibility and lightness, are much prone to the wind loads, aerodynamics performance has become an important aspect of the design of long-span suspension bridges. In this study, the static wind load acting on the suspension bridge during erection has been investigated through wind tunnel test and numerical analysis. The wind tunnel test was performed using a 1:50 scale section model of the bridge, the static wind load acting on the section model was measured with varying attack angles. Numerical method used here was computational fluid dynamics simulation, a two-dimensional model is adopted in the first stage of the analysis, then the SIMPLE algorithm was employed to solve the governing equations. The analytical results were compared with the wind tunnel test data, it was shown from the study that the results of CFD simulation was good agreement with that of the wind tunnel test.

scholarly journals Identification of Sharp Edge Non-Slender Delta Wing Aerodynamic Coefficient Using Neural Network

2021 ◽  
Vol 2129 (1) ◽  
pp. 012086
Author(s):  
Fahmi Izzuddin Abdul Rahman ◽  
Shabudin Mat ◽  
Nor Haizan Mohamed Radzi ◽  
Mohd Nazri Mohd Nasir ◽  
Roselina Sallehudin
Keyword(s):  
Neural Network ◽  
Wind Tunnel ◽  
Transfer Functions ◽  
Delta Wing ◽  
Flow Analysis ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Training Data ◽  
Vortical Flow ◽  
Sharp Edge

Abstract Delta wing formed a vortical flow on its surface which produced higher lift compared to conventional wing. The vortical flow is complex and non-linear which requires more studies to understand its flow physics. However, conventional flow analysis (wind tunnel test and computational flow dynamic) comes with several significant drawbacks. In recent times, application of neural network as alternative to conventional flow analysis has increased. This study is about utilization of Multi-Layer Perceptron (MLP) neural network to predict the coefficient of pressure (Cp ) on a delta wing model. The physical model that was used is a sharp edge non-slender delta wing. The training data was taken from wind tunnel tests. 70% of data is used as training, 15% is used as validation and another 15% is used as test set. The wind tunnel test was done at angle of attack from 0°-18° with increment of 3°. The flow velocity was set at 25m/s which correspond to 800,000 Reynolds number. The inputs are angle of attack and location of pressure tube (y/cr) while the output is Cp . The MLP models were fitted with 3 different transfer functions (linear, sigmoid, and tanh) and trained with Lavenberg-Marquadt backpropagation algorithm. The results of the models were compared to determine the best performing model. Results show that large amount of data is required to produce accurate prediction model because the model suffer from condition called overfitting.

Validation of CFD Modeling and Simulation of a Simplified Automotive Model

2015 ◽  
Vol 735 ◽  
pp. 319-325
Author(s):  
S. Mansor ◽  
N.A.R. Nik Mohd ◽  
C.W. Chung
Keyword(s):  
Wind Tunnel ◽  
Modeling And Simulation ◽  
Best Practice ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Turnaround Time ◽  
Cfd Modeling ◽  
Design Changes ◽  
Wind Tunnel Data ◽  
Simulation Results

In the early design phase of automotive sector, the flow field around the vehicle is important in decision making on design changes. It would consume a lot of money and time for multiple prototypes development if adopt traditional testing method which is wind tunnel test. Thus, numerical method such as Computational Fluid Dynamics (CFD) simulation plays an important role here. It is very often simulation results been compared with wind tunnel data. However, with various mesh types, meshing methodology, discretization methods and different solver control options in CFD simulation, users may feel low confidence level with the generated simulation results. Thus, a robust modeling and simulation guideline which would help in accurate prediction should be developed due to the industry’s demand for accuracy when comparing CFD to wind tunnel results within short turnaround time. In this paper, a CFD modeling and simulation study was conducted on a simplified automotive model to validate with wind tunnel test results. The wind tunnel environment was reproduced in the simulation setup to include same boundary conditions. Meshing guidelines, turbulence model comparisons and also the best practice for solver setup with respect to accuracy will be presented. Overall, CFD modeling and simulation methods applied in this paper are able to validate the results from experiment accurately within small yaw ranges.

3-D CFD Simulation of the Airflow over a Gable Roof with Different Elevations

2015 ◽  
Vol 769 ◽  
pp. 229-234
Author(s):  
Juraj Jr. Kralik
Keyword(s):  
Wind Tunnel ◽  
Turbulence Model ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Turbulence Models ◽  
Accurate Method ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Pressure Coefficients ◽  
Gable Roof

The pressure coefficients on duo-pitched roofs of separated buildings are well described by several standards. Nowadays, there are various commercial or non-commercial programs which can predict the pressure coefficients. However, the most accurate method is to perform a wind tunnel test. The aim of this paper is to simulate the airflow over a gable roof with different elevations under ANSYS Fluent 14.0 program. Examined elevations of the gable roof are 5°, 15° and 30°. Classical two equation k-ε turbulence models based on Reynolds Averaged Navier-Stokes (RANS) equations simulation were performed. Performance of each turbulence model with the increasing angel of the roof was compared.

scholarly journals Aerodynamic research of a racing car based on wind tunnel test and computational fluid dynamics

2018 ◽  
Vol 153 ◽  
pp. 04011
Author(s):  
Jianfeng Wang ◽  
Hao Li ◽  
Yiqun Liu ◽  
Tao Liu ◽  
Haibo Gao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Aerodynamic Forces ◽  
Automotive Aerodynamics

Wind tunnel test and computational fluid dynamics (CFD) simulation are two main methods for the study of automotive aerodynamics. CFD simulation software solves the results in calculation by using the basic theory of aerodynamic. Calculation will inevitably lead to bias, and the wind tunnel test can effectively simulate the real driving condition, which is the most effective aerodynamics research method. This paper researches the aerodynamic characteristics of the wing of a racing car. Aerodynamic model of a racing car is established. Wind tunnel test is carried out and compared with the simulation results of computational fluid dynamics. The deviation of the two methods is small, and the accuracy of computational fluid dynamics simulation is verified. By means of CFD software simulation, the coefficients of six aerodynamic forces are fitted and the aerodynamic equations are obtained. Finally, the aerodynamic forces and torques of the racing car travel in bend are calculated.

Numerical and Experimental Study of Ice Accretion Process and Ice Protection on Turbo-Fan Engine Splitter

2019 ◽  
Author(s):  
Yutao Zheng ◽  
Fukun Zhang ◽  
Daijun Wang ◽  
Si Li
Keyword(s):  
Wind Tunnel ◽  
Test Piece ◽  
Cfd Simulation ◽  
Energy Requirement ◽  
Flow Analysis ◽  
Simulation Method ◽  
Electrical Heating ◽  
External Boundary ◽  
Ice Accretion ◽  
Two Phase

Abstract The splitter, a steady component in the downstream of fan blades in the turbo-fan engine, will be exposed to an icing environment when the engine is working in icing conditions. An anti-icing system should be used on the splitter in order to make the engine work well and not be affected by icing. In this study, both of experiments and CFD simulations were applied to acquire icing characteristics and the electronic anti-icing system’ energy requirement for this component. Factors of icing conditions varied from attacking angle, ambient temperature and pressure, air velocity and droplet factors. Experiments were performed in the AVIC Aerodynamics Research Institute Icing Wind Tunnel (FL-61). The test component was a combination of an arc segment of splitter and seven pieces of inlet guide vanes, covered by electrical heating film. The experiment was carried out under different icing conditions in the icing wind tunnel. Ice profiles, the results of icing experiment, were collected by 3D scanner. Anti-icing surface temperature profiles were collected by thermocouples. The CFD results of icing process were compared with the experimental data for validation, and showed that the droplet collection of on the lower surface of splitter was significant. The CFD simulation was established on the two-phase flow analysis conducted by ANSYS-CFX and Fensap-ice for the prediction on ice accretion, and a coupled simulation method was introduced to replace the conjugate simulation method for thermal analysis with a higher working efficiency in engineering design. Through the icing simulation, an estimated external boundary condition was applied on the thermal model of the test piece and the temperature field on the test piece was calculated.

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