scholarly journals Computational Analyses of the Effects of Wind Tunnel Ground Simulation and Blockage Ratio on the Aerodynamic Prediction of Flow over a Passenger Vehicle

Vehicles ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 318-341
Author(s):  
Chen Fu ◽  
Mesbah Uddin ◽  
Chunhui Zhang
Keyword(s):  
Wind Tunnel ◽  
Boundary Conditions ◽  
Physical Simulation ◽  
Cost Effective ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Scale Model ◽  
Blockage Ratio ◽  
Road Tunnel ◽  
Test Conditions

With the fast-paced growth of computational horsepower and its affordability, computational fluid dynamics (CFD) has been rapidly evolving as a popular and effective tool for aerodynamic design and analysis in the automotive industry. In the real world, a road vehicle is subject to varying wind and operating conditions that affect its aerodynamic characteristics, and are difficult to reproduce in a traditional wind tunnel. CFD has the potential of becoming a cost-effective way of achieving this, through the application of different boundary conditions. Additionally, one can view wind tunnel testing, be it a fixed-floor or rolling road tunnel, as a physical simulation of actual on-road driving. The use of on-road track testing, and static-floor, and rolling-road wind tunnel measurements are common practices in industry. Subsequently, we investigated the influences of these test conditions and the related boundary conditions on the predictions of the aerodynamic characteristics of the flow field around a vehicle using CFD. A detailed full-scale model of Hyundai Veloster with two vehicle configurations, one with the original and the other with an improved spoiler, were tested using a commercial CFD code STAR-CCM+ from Siemens. Both vehicle configurations were simulated using four different test conditions, providing overall eight different sets of simulation settings. The CFD methodology was validated with experimental data from the Hyundai Aero-acoustic Wind Tunnel (HAWT), by accurately reproducing the test section with static floor boundary conditions. In order to investigate the effect of the blockage ratio on the aerodynamic predictions, the vehicle models were then tested with moving ground plus rotating wheel boundary conditions, using a total of four virtual wind tunnel configurations, with tunnel solid blockage ratios ranging from 1.25%, which corresponds to the actual HAWT, to 0.04%, which presents an open air driving condition.

scholarly journals 2D Numerical Simulation Study of Airfoil Performance

2021 ◽  
Author(s):  
Nasser Shelil
Keyword(s):  
Experimental Data ◽  
Wind Tunnel ◽  
Air Temperature ◽  
Wind Turbines ◽  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Turbulence Models ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Ansys Fluent

Abstract. The aerodynamic characteristics of DTU-LN221 airfoil is studied. ANSYS Fluent is used to simulate the airfoil performance with seven different turbulence models. The simulation results for the airfoil with different turbulence models are compared with the wind tunnel experimental data performed under the same operating conditions. It is found that there is a good agreement between the computational fluid dynamics (CFD) predicted aerodynamic force coefficients with wind tunnel experimental data especially with angle of attack between −5° to 10°. RSM is chosen to investigate the flow field structure and the surface pressure coefficients under different angle of attack between −5° to 10°. Also the effect of changing air temperature, velocity and turbulence intensity on lift and drag coefficients/forces are examined. The results show that it is recommended to operate the wind turbines airfoil at low air temperature and high velocity to enhance the performance of the wind turbines.

scholarly journals Performance prediction of loop-type wind turbine

2020 ◽  
Vol 12 (2) ◽  
pp. 168781401984047
Author(s):  
Wonyoung Jeon ◽  
Jeanho Park ◽  
Seungro Lee ◽  
Youngguan Jung ◽  
Yeesock Kim ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Experimental Results ◽  
Scale Model ◽  
Dynamics Analysis ◽  
Blockage Ratio ◽  
Horizontal Axis Wind Turbine ◽  
Computational Fluid Dynamics Analysis

An experimental and analytical method to evaluate the performance of a loop-type wind turbine generator is presented. The loop-type wind turbine is a horizontal axis wind turbine with a different shaped blade. A computational fluid dynamics analysis and experimental studies were conducted in this study to validate the performance of the computational fluid dynamics method, when compared with the experimental results obtained for a 1/15 scale model of a 3 kW wind turbine. Furthermore, the performance of a full sized wind turbine is predicted. The computational fluid dynamics analysis revealed a sufficiently large magnitude of external flow field, indicating that no factor influences the flow other than the turbine. However, the experimental results indicated that the wall surface of the wind tunnel significantly affects the flow, due to the limited cross-sectional size of the wind tunnel used in the tunnel test. The turbine power is overestimated when the blockage ratio is high; thus, the results must be corrected by defining the appropriate blockage factor (the factor that corrects the blockage ratio). The turbine performance was corrected using the Bahaj method. The simulation results showed good agreement with the experimental results. The performance of an actual 3 kW wind turbine was also predicted by computational fluid dynamics.

scholarly journals Planetary Atmosphere Wind Tunnel Tests on Aerodynamic Characteristics of a Mars Airplane Scale Model

2014 ◽  
Vol 12 (ists29) ◽  
pp. Pk_7-Pk_12 ◽  
Author(s):  
Masayuki ANYOJI ◽  
Masato OKAMOTO ◽  
Hidenori HIDAKA ◽  
Taku NONOMURA ◽  
Akira OYAMA ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Characteristics ◽  
Planetary Atmosphere ◽  
Scale Model ◽  
Wind Tunnel Tests

A Redesign Strategy to Improve the Efficiency of a 17-Stage Steam Turbine

2009 ◽  
Author(s):  
Filippo Rubechini ◽  
Andrea Schneider ◽  
Andrea Arnone ◽  
Stefano Cecchi ◽  
Francesco Malavasi
Keyword(s):  
Neural Network ◽  
Boundary Conditions ◽  
Steam Turbine ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Second Step ◽  
Geometrical Transformation ◽  
First Approximation ◽  
Original Reference

A three-dimensional RANS solver was applied to the aerodynamic redesigning of a 17-stage steam turbine. The redesign procedure was divided into three steps. In the first one, a single embedded stage was considered, and an optimization of stator lean and rotor twist was carried out by applying suitable repeating inlet/outlet boundary conditions. In the second step, a proper geometrical transformation between the original reference stage and the optimized one was identified and then applied to all other turbine stages, thus leading to a first approximation of the redesigned turbine. Finally, a neural-network-based refinement of the stator and rotor twist of each stage was performed to account for its actual position and operating conditions within the meridional channel. In this work, a detailed description of the redesign procedure is provided, and the aerodynamic characteristics of the optimized geometry are discussed and compared to the original ones.

Aerodynamics of Urban Maglev vehicles

2012 ◽  
Vol 226 (6) ◽  
pp. 561-567 ◽  
Author(s):  
Colin P Britcher ◽  
John M Wells ◽  
Benoit Renaud ◽  
Thibaut Buvat
Keyword(s):  
Wind Tunnel ◽  
Historical Data ◽  
Aerodynamic Characteristics ◽  
Scale Model ◽  
Wind Environment ◽  
Wind Tunnel Tests ◽  
Low Speed ◽  
Lateral Forces ◽  
Old Dominion University

Some aerodynamic issues affecting low-speed Urban Maglev vehicles are studied, focusing primarily on the effect of ambient winds on levitation electromagnet loads. Aerodynamic characteristics of a representative vehicle are estimated by means of wind tunnel tests of a 1/12th scale model. The wind environment influencing the existing Maglev guideway at Old Dominion University are established from historical data. It is shown that ambient winds, particularly crosswinds, can pose significant challenges, including substantial redistribution of levitation forces among vehicle electromagnets. The development of large lateral forces, particularly at the forward electromagnet stations, may also be of concern.

scholarly journals Wind Tunnel Tests of Influence of Boosters and Fins on Aerodynamic Characteristics of the Experimental Rocket Platform

2017 ◽  
Vol 2017 (4) ◽  
pp. 82-102
Author(s):  
Paweł Ruchała ◽  
Robert Placek ◽  
Wit Stryczniewicz ◽  
Jan Matyszewski ◽  
Dawid Cieśliński ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Drag ◽  
Wind Tunnel Test ◽  
Longitudinal Axis ◽  
Aerodynamic Characteristics ◽  
Scale Model ◽  
Wind Tunnel Tests ◽  
Aerodynamic Loads ◽  
Microgravity Experiments ◽  
Image Velocimetry

Abstract The paper presents results of wind tunnel tests of the Experimental Rocket Platform (ERP), which is developed in Institute of Aviation. It is designed as an easy accessible and affordable platform for microgravity experiments. Proposed design enables to perform experiments in microgravity for almost 150 seconds with apogee of about 100 km. The full-scale model of the ERP has been investigated in the T-3 wind tunnel in Institute of Aviation. During the investigation, the aerodynamic loads of the rocket has been measured for the angle of attack up to 10° and the different rotation angle around the longitudinal axis (up to 90°, depending on the configuration). Three configurations has been investigated: • without fins and boosters • with fins and without boosters • with fins and boosters Additionally, the measurements of velocity field around the ERP using the Particle Image Velocimetry (PIV) has been performed. Based on the wind tunnel test, an influence of fins and boosters on aerodynamic characteristics of the rocket has been described. Results of the wind tunnel tests show relatively high contribution of boosters in total aerodynamic drag. Some conclusions concerning performance and stability of the rocket have been presented.

Aerodynamic characteristics of helicopter engine side air intakes

2018 ◽  
Vol 90 (9) ◽  
pp. 1355-1363
Author(s):  
Florian Knoth ◽  
Christian Breitsamter
Keyword(s):  
Mass Flow ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Scale Model ◽  
Pressure Probe ◽  
Data Set ◽  
Flow Rates ◽  
Content Type ◽  
Plenum Chamber ◽  
Mass Flow Rates

PurposeAerodynamic characteristics of engine side air intakes for a lightweight helicopter are investigated aiming to achieve an efficient engine airframe integration. Design/methodology/approachOn a novel full-scale model of a helicopter fuselage section, a comprehensive experimental data set is obtained by wind tunnel testing. Different plenum chamber types along with static side intake and semi-dynamic side intake configurations are considered. Engine mass flow rates corresponding to the power requirements of realistic helicopter operating conditions are reproduced. For a variety of freestream velocities and mass flow rates, five-hole pressure probe data in the aerodynamic interface plane and local surface pressure distributions are compared for the geometries. FindingsIn low-speed conditions, unshielded, sideways facing air intakes yield lowest distortion levels and total pressure losses. In fast forward flight condition, a forward-facing intake shape is most beneficial. Additionally, the influence of an intake grid and plenum chamber splitter is evaluated. Originality/valueThe intake testing approach and the trends found can be applied to other novel helicopter intakes in early development stages to improve engine airframe integration and decrease development times.

Design and Evaluation Measurements of a Swirl Stabilized Laboratory Burner

2005 ◽  
Vol 219 (10) ◽  
pp. 1079-1086 ◽  
Author(s):  
N G Orfanoudakis ◽  
A Hatziapostolou ◽  
K Krallis ◽  
N Vlachakis
Keyword(s):  
Rotary Kiln ◽  
Combustion Process ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Temperature Measurements ◽  
Gaseous Fuel ◽  
Scale Model ◽  
Solid Fuels ◽  
Experimental Measurements ◽  
Gas Velocity

This article presents gas velocity and temperature measurements obtained in a versatile multi-fuel swirl-stabilized laboratory burner of 100 kW total thermal input, which was designed as a scale model of a 110 MW coal burner operating in a cement rotary kiln. The laboratory burner is able to produce flames with different aerodynamic characteristics, namely, the independent adjustment of swirl to axial air and to burn a combination of gaseous, liquid, and pulverized solid fuels; only gaseous fuel, i.e. methane, was used in the present investigation. Experimental measurements were obtained in the near-burner region, with and without combustion, under varying operating conditions. The present investigation was mainly focused on the effect of swirl and its interaction with the combustion process.

Effects of Embankment Scenario on the Aerodynamic Coefficients of a Railway Vehicle Through Wind Tunnel Tests

2012 ◽  
Author(s):  
F. Cheli ◽  
F. Fiocco ◽  
S. Giappino ◽  
G. Tomasini
Keyword(s):  
Wind Tunnel ◽  
Boundary Conditions ◽  
Finite Length ◽  
Aerodynamic Force ◽  
Scale Model ◽  
Railway Vehicle ◽  
Aerodynamic Coefficients ◽  
Wind Tunnel Tests ◽  
Scale Models ◽  
Typical Layout

Embankment is a typical layout for rail infrastructures and train aerodynamic coefficients in this scenario are necessary for the analysis of cross wind effects. Nevertheless wind tunnel tests on scale models with the embankment scenario presents difficulties in the reproduction of the boundary conditions, that is the simulation of a “pseudo-infinite” full scale embankment. To investigate this topic we have performed wind tunnel tests on an ETR500 1:45 scale model using a finite length embankment, with and without an upwind nose and a “pseudo-infinite” embankment, reproduced by the extension wall-to-wall of the scenario. The paper presents the tests results in terms of aerodynamic force coefficients and surface pressures. Guidelines for wind tunnel tests on embankment are than discussed.

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