Effect of Vortex Generator on Flow Field Quality in 3/4 Open Jet Automotive Wind Tunnel

2017 ◽  
Vol 10 (1) ◽  
pp. 224-234 ◽  
Author(s):  
Di Bao ◽  
Qing Jia ◽  
Zhigang Yang
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Vortex Generator ◽  
Field Quality

The Study of Design and Installation Process for Supersonic Nozzle

2012 ◽  
Vol 569 ◽  
pp. 500-503
Author(s):  
Lian Sheng Wu ◽  
Guang Li Li ◽  
Qi Fu
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Test Section ◽  
Supersonic Nozzle ◽  
Simulation Method ◽  
Supersonic Wind Tunnel ◽  
Numerical Simulation Method ◽  
Field Quality ◽  
The Impact

A practical optimal design method of supersonic nozzle is proposed for a supersonic wind tunnel’s design. Design a set of nozzle wall lines with the same nozzle length and different Mach numbers 1.5, 2.0, 2.5. Use numerical simulation method for the verify and analysis of the designed nozzle. Mainly study the impact of the installation gradient between nozzle and test section on flow field quality. This wind tunnel is the subsonic, transonic and supersonic wind tunnel and its test section cross is 0.2 m × 0.2 m .The impact on flow field quality of the test section was studied quantitatively by using the numerical simulation method. The installation gradient index was given. It has some practical value to the construction of supersonic wind tunnel. At present, this study has been applied in construction of the wind tunnel. The gradient of the test section import shall not be greater than 0.5 mm.

Design of Flow Adjusting Device in Diffuser of Open-Circuit Wind Tunnel with Low Speed Based on CFX

2015 ◽  
Vol 799-800 ◽  
pp. 640-644
Author(s):  
Xiao Yi Wang ◽  
Chong Gao ◽  
Fu Qiang Chen ◽  
Yu Hua Zhang ◽  
Zhi Zhen Qiu
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
High Speed ◽  
Reference Frames ◽  
Open Circuit ◽  
Analysis Model ◽  
Low Speed ◽  
Guide Plate ◽  
Study Results ◽  
Field Quality

The diffuser in wind tunnel plays a vital role to improve flow field quality. Many flow adjusting devices in diffuser were studied by lots of researchers in the world to inhibit flow separation. However, most of them were applied on closed-circuit wind tunnel with high speed. It is necessary to design appropriate flow adjusting device for diffuser in open-circuit wind tunnel with low speed which was increasingly used in aerodynamic experiment. The structure of a new open-circuit wind tunnel with low speed was firstly introduced in this paper. The flow adjusting device was designed, which was composed of three parts, namely contracting cone, air guide plate and screen. On the basis of analysis model for diffuser, the influences of contracting cone, air guide plate and screen on flow field quality were respectively given by CFX simulation that was using multiple reference frames and RNG k-ε turbulence model. Case study showed that the role of single part was limited, combined effect of three parts in flow adjusting device could greatly improve quality of flow field in diffuser. The study results mentioned above are useful for designing flow adjusting device in diffuser of practical open-circuit wind tunnel with low speed.

scholarly journals EFFECT OF THE FLOW FIELD DEFORMATION IN THE WIND TUNNEL ON THE AERODYNAMIC COEFFICIENTS

2015 ◽  
Vol 55 (3) ◽  
pp. 177-186
Author(s):  
Dušan Maturkanič
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Test Section ◽  
Air Flow ◽  
Wind Tunnels ◽  
Aerodynamic Coefficients ◽  
Wind Tunnel Measurement ◽  
Field Quality ◽  
Entire Flow ◽  
The Creation

The flow field quality has a principal signification at wind tunnel measurement. The creation of the flow field of air by fan leads to the rotation of entire flow field which is, moreover, deformed at the bends of the wind tunnel with close circulation. Despite the wind tunnels are equipped with the devices which eliminate these non-uniformities, in the most of cases, the air flow field has not ideal parameters in the test section. For the evaluation of the measured results of the model in the wind tunnel, the character of flow field deformation is necessary. The following text describes the possible general forms of the flow field nonuniformity and their effect on the aerodynamic coefficients calculation.

Characteristic model-based adaptive control for cryogenic wind tunnels

2020 ◽  
pp. 014233122096065
Author(s):  
Chenhui Yu ◽  
Fei Liao ◽  
Haibo Ji ◽  
Wenhua Wu
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Flow Field ◽  
Control Problem ◽  
Mimo System ◽  
Adaptive Controller ◽  
Characteristic Model ◽  
Model Based ◽  
Field Control ◽  
Cryogenic Wind Tunnel

With the increasing requirement of Reynolds number simulation in wind tunnel tests, the cryogenic wind tunnel is considered as a feasible method to realize high Reynolds number. Characteristic model-based adaptive controller design method is introduced to flow field control problem of the cryogenic wind tunnel. A class of nonlinear multi-input multi-output (MIMO) system is given for theoretical research that is related to flow field control of the cryogenic wind tunnel. The characteristic model in the form of second-order time-varying difference equations is provided to represent the system. A characteristic model-based adaptive controller is also designed correspondingly. The stability analysis of the closed loop system composed of the characteristic model or the exact discrete-time model and the proposed controller is investigated respectively. Numerical simulation is presented to illustrate the effectiveness of this control method. The modeling and control problem based on characteristic model method for a class of MIMO system are studied and first applied to the cryogenic wind tunnel control field.

Numerical Simulation of Flowfield around High Speed Trains Passing by each other at the same Speed

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Point Source ◽  
High Speed ◽  
Stokes Equations ◽  
Field Structure ◽  
Vehicle Speed ◽  
Mesh Method ◽  
High Speed Trains

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.

Improved model predictive control for the flow field in a wind tunnel with model uncertainty

2020 ◽  
Vol 357 (12) ◽  
pp. 7439-7455
Author(s):  
Yanming Liu ◽  
Junjie Wang ◽  
Xiaotao Liu ◽  
Xiaoping Li ◽  
Bo Yao ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Model Uncertainty ◽  
Improved Model
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