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.

CFD Simulation of Large Dust Collection Cyclones Positioned Vertically in Staggered Downward Cascade Arrangement

2013 ◽  
Author(s):  
Eugen-Dan Cristea ◽  
Pierangelo Conti
Keyword(s):  
Cfd Simulation ◽  
Solid Phase ◽  
Phase Particle ◽  
High Mass ◽  
Cfd Modeling ◽  
Cement Kiln ◽  
Dust Collection ◽  
Dry Process ◽  
Cascade Arrangement ◽  
Simulation Results

Three dimensional, time dependent Euler-Euler simulation approach for numerical calculation of multiphase strongly swirling turbulent gas-heavy laden particulate flow in large industrial collection cyclones, positioned vertically, in staggered downward cascade arrangement has been performed. The multiphase flow was featured high mass loading. This paper specifically addresses a CFD modeling of a “suspension preheater”, typical equipment for dry process cement kiln. Big sized cyclone separator is a key component of this device. The simulation case study was developed in the frame of the commercial general-purpose code ANSYS-Fluent R13. In cyclone separators the swirling gas motion induces a centrifugal force on the solid particulate phase which is the driving force behind the separation process. The turbulence disperses the solid particulates and enhances the probability that particles are discharged, as reject. Both phenomena are related to solid phase particle size distribution (PSD) and flow pattern into the collection cyclones. The multiphase turbulence was modeled using the RSM Mixture Turbulence Model. The simulation results were validated against industrial measurements carried out on an industrial suspension preheater, in the frame of heat and mass balance of cement kiln energy audit. The numerical simulation results were found in reasonable agreement with the collected industrial measurements. This CFD simulation represents a powerful engineering tool on behalf of the cement process engineer either for new cutting-edge design or for performance verification of an existing plant.

Slung Load Amplification Detector

2017 ◽  
Author(s):  
Nandeesh Hiremath ◽  
Dhwanil Shukla ◽  
Emily Hale ◽  
Taylor Sparacello ◽  
Narayanan Komerath
Keyword(s):  
Wind Tunnel ◽  
Flight Speed ◽  
Dynamics Simulation ◽  
Test Cases ◽  
Specific Load ◽  
Top Down ◽  
Practical Test ◽  
Life Threatening ◽  
Wind Tunnel Data ◽  
Simulation Results

Externally slung loads and their mission applications are becoming more common on human and autonomously piloted air vehicles. Flight speed is often limited not by the performance envelope but by the danger of divergent load oscillations. Certifying this limiting speed for every load-vehicle combination, is a huge barrier to operations. The conservatism dictated by this uncertainty may itself be life-threatening in critical applications. Computing the dynamics of slung loads for a specific load/vehicle combination has been hindered by lack of knowledge on bluffbody aeromechanics. The prevailing top-down approach is to incorporate slung load aeromechanics calculations into large comprehensive aeromechanics codes for rotorcraft. We argue for a bottom-up approach. This allows on-the-fly system identification and dynamics simulation. The Slung Load Amplification Detector (SLAD) concept provides an on-board safety system to predict, detect, avoid and alleviate divergent oscillations. SLAD is based on a knowledge base derived from wind tunnel data and simulation results including canonical geometries, as well as practical shapes. Validation of simulation results against two practical test cases lends confidence. SLAD allows reliable distinction between pseudo and absolute divergence, permitting an increase of as much as 50% speed in safe flight speed, and guidance on active alleviation of oscillations.

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.

CFD Simulation of a Simplified Automotive Model for Various Rear Slant Angle

2014 ◽  
Vol 660 ◽  
pp. 724-729
Author(s):  
S. Mansor ◽  
N.A.R. Nik Mohd ◽  
C.W. Chung
Keyword(s):  
Constant Velocity ◽  
Cfd Simulation ◽  
Pressure Coefficient ◽  
Wind Tunnel Test ◽  
Slant Angle ◽  
Testing Method ◽  
Design Changes ◽  
Yaw Angle ◽  
Height Model ◽  
Early Design Phase

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, CFD Simulation plays an important role here. In this paper, a CFD simulation study was conducted on a simplified automotive model called Davis model with constant velocity of 40 m/s. Modification of rear slant angle bring significant effects on the wakes produced which also affect the drag performance. Many configurations of body designs can be produced by a single rear slant angle. So that, fixed rear slope and fixed rear height configuration have been chosen for investigations for various rear slant angles. In this paper, the flow of Davis model especially on the rear slanted surface is discussed. Pressure coefficient contour, pressure coefficient plot and vorticity structures are presented. This work shows that the drag coefficient value vary between fixed rear slope model and fixed rear height model even for the same rear slant angle under a range of yaw angle.

scholarly journals Experimental Analysis of a Small-Scale Rotor at Various Inflow Angles

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Amir Kolaei ◽  
Devin Barcelos ◽  
Götz Bramesfeld
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Axial Flow ◽  
Unmanned Aircraft ◽  
Performance Characteristics ◽  
Small Scale ◽  
Flow Conditions ◽  
Wind Tunnel Experiments ◽  
Wind Tunnel Data ◽  
Advance Ratio

The performance characteristics of a rotor that is typically used for small unmanned aircraft were analyzed in a series of wind-tunnel experiments. Wind-tunnel measurements were conducted with the rotor at various inflow angles in order to investigate the effects on the rotor performance of partially or fully edgewise flow as they are typically encountered with small multirotor vehicles. Rotor tests were also performed under static and fully axial flow conditions in order to investigate the aerodynamic performance during hover as well as vertical climb and descent. The wind-tunnel data were corrected to account for the interference of wind-tunnel walls with the rotor wake and the blockage due to the presence of the rotor test stand in the wind-tunnel test section. The results are presented in terms of thrust, power, and roll moment coefficients under different rotor rotational speeds for a T-motor 18x6.1. Additionally, the measured thrust and power coefficients of Master Airscrew Electric 11x7 are compared with available propeller data under static and axial flow conditions for verification purposes. It is shown that the rotor performance characteristics are strongly affected by the freestream advance ratio and the freestream inflow angles. For example, at inflow angles that are typical for multirotor vehicles between about 15° and 0° with respect to the rotor disc, thrust coefficients stay constant or grow with increasing advance ratio, whereas power coefficients remain relatively constant with changing advance ratio.

Numerical Simulation and Wind Tunnel Studies of the Wind Load on Wind Turbine Structures

2011 ◽  
Vol 250-253 ◽  
pp. 3811-3814
Author(s):  
Cheng Hsin Chang ◽  
Jen Mu Wang ◽  
Chii Ming Cheng
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Tunnel Test ◽  
Bending Moment ◽  
Dynamic Mesh ◽  
Base Shear ◽  
Structural Responses ◽  
Simulation Results ◽  
Rng Turbulence Model

This paper investigated the structural responses of the wind turbine due to wind loads by performing the wind tunnel test and the Computational Fluid Dynamics, (CFD). The base shear force and the base moment of the wind turbine measured by the wind tunnel test were compared with the numerical simulation results. Both the numerical dynamic mesh and sliding mesh models were selected for the numerical simulations. The results showed that the dynamic mesh model was better than the sliding model by comparing to the wind tunnel test result. In the case of the k-epsilon RNG turbulence model, the prediction of the bending moment affecting by acrossswind was more than 50%, and the prediction of the force affecting by acrosswind was less than 3%. The both simulation results of the prototype and the full scale wind turbine were obtained by CFD model. The comparisons of the result showed that the error of Fxwas about 15% and Mywas about 13.5%.

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