Adaptive Control of Flow Separation in a Planar Diffuser

 

          
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Cp (t)

1

A1sin(25f t)

Pressure Pressurerecovery recovery calculation calculation 0

Pressure measurement

-1

Extremum-seeking Extremum-seeking algorithm algorithm

0.1

Synthetic jet actuator

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.19

0.2

+

1

A2sin(25 2f t-6) 0

Adjustable parameters

Ai , fi ,6i ,i 1..N

Multi-frequency Multi-frequency forcing forcing

Speaker command

N

U (t )  ¦ Ai sin( 25f i t 6 i )

-1 0.1

i 1

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.19

0.2

||

2


             



U(t)

0

             

-2 0.1

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0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.19

0.2


                                 

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50

0.05

45

40

0 0.1

Frequency

35 0.2 30

25

0.15

20 0.1

0.1 15 0.05 10 −150

−100

−50

0

50

100

150

Phase

50

0.05

0

45

40 0.05

Frequency

35 0.1

0.15 0

30 0.1 0.05

25

20

0

15 −0.05 10 −150

−100

−50

0

50

100

150

Phase


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Time evolution of mean C_p 0.25 0.2 0.15 0.1

0.4 0.05

0.35 0

0

10

20

30 Time in seconds

40

50

60

Pressure Recovery

0.3

Freqency of forcing in Hz 50

0

45 40

100

200

40

300

400

500

600

700

500

600

700

Time (second)

35 30 25

Frequency 20

20 15 10

0

10

20

30 Time in seconds

40

50

60

0

100

200

Control phase in degrees 150

Magnitudes

1

100

300

400

Time (second)

A1

50

0.5

0

0

−50

0

−100 −150

100

200

40 0

10

20

30 Time in seconds

40

50

60

500

600

700

500

600

700

0 -20 -40

Phases

-60 0

100

200

300

400

Time (seconds)

Time evolution of mean C_p

0.22

400

Time (second)

20


 )    (           (            * +  Time evolution of mean C_p

300

0.25

0.2

0.2

0.18 0.15 0.16 0.1 0.14 0.05

0.12 0.1

0

10

20

30 Time in seconds

40

50

60

0

0

10

20

Freqency of forcing in Hz

30 Time in seconds

40

50

60

Freqency of forcing in Hz

40

50 45

35 40 30

35 30

25 25 20

0

10

20

30 Time in seconds

40

50

60

20

0

10

20

Control phase in degrees

30 Time in seconds

40

50

60

40

50

60

Control phase in degrees

200

120 100

150 80 100

60

50

40 20

0 0 −50

0

10

20

30 Time in seconds

40

50

60

−20

0

10

20

30 Time in seconds


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