A study on Linear Reduced-order Model based on …Boeing/ppt/20191212/6.Nankai.pdfA study on Linear...
Transcript of A study on Linear Reduced-order Model based on …Boeing/ppt/20191212/6.Nankai.pdfA study on Linear...
Dec. 12 2019 Boeing Higher Education
A study on Linear Reduced-order Model based on PIV Data of Flow Field around Airfoil
Koki NANKAI (Tohoku University, Japan)
Boeing Higher Education Program Year 2019 Performance Report
Boeing Japan, Maru-no-uchi,Tokyo
December 12, 2019 15:20 – 15:35
Dec. 12 2019 Boeing Higher Education
Flow field around airfoil
1
Flow separation (stall) Decrease in lift
Increase in drag
Angle of attack α
Lift
αFlow
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Active flow control
2
Separation control using PA Lift enhancement
Drag reduction
Various control input
‒ Voltage
‒ Frequency
‒ Burst frequency (F+)
Feedback control Control input based on output
High robustness
Necessary to know state of flow fields
A model which estimates
the time advancement of
flow fields is necessary
Aono et al., AIAA J., 2017
F+ = 1
F+ = 5
Flow Field
Sensor
+−
DBD-PA
(Active Control Devices)
Observer
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Objective
3
Construct the model of flow fields around an airfoil based
on experimental data
Experiment (Wind tunnel testing)
Order reduction of data
Modeling by a linear equation
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Experiment
4
Wind tunnel testing
Particle image velocimetry (PIV)
Camera
Laser
Airfoil
Flow
Airfoil
t
t + dt
Experimental setup (at IFS, Tohoku university)
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Modeling approach
5
Order reduction of data using POD technique
Modeling using linear equation
1st mode 2nd mode 𝑟 th mode
⋯⋯
⋯⋯
⋯⋯
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Reconstructed dataOriginal dataPOD
Order
reduction
zn+1 = Aznzn
A:Flow field at nth time step
:Coefficient matrix
A is calculated from experimental (PIV) data
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Results
6
PIV measurements Time-averaged velocity fields
Time-resolved velocity fields
14 deg 16 deg 18 deg 20 deg 22 deg
14 deg 16 deg 18 deg 20 deg 22 deg
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Results (α = 18 deg)
7
Reconstruction of fluid data using POD
PIV result Reconstructed
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Results (α = 18 deg)
8
Temporal estimation by the model
Original Model
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Conclusions
9
The linear reduced-order model of flow fields around the
airfoil was constructed based on experimental data
Experiment (Wind tunnel testing)
‒ Velocity fields data were acquired by PIV
Order reduction of data
‒ The order of fluid data was reduced drastically by POD
Modeling by a linear equation
‒ The model can reproduce the original data with low computational cost