11 1 CFDVAL Langley Research Center Workshop CFD Validation of Synthetic Jets and Turbulent Separation Control Woodlands Hotel and Conference Center Colonial.

1 1 1

CFDVAL

Langley Research Center WorkshopCFD Validation of Synthetic Jets and Turbulent Separation Control

Woodlands Hotel and Conference CenterColonial Williamsburg, Williamsburg, Virginia, USA

March 29-31, 2004

George Huang, Raymond LeBeau,Hua Chen, Liang Huang,

Vamsidhar Katam, Vimal Parimi and Yih-Nen JengDepartment of Mechanical Engineering

University of KentuckyLexington, KY

2 2 2

CFD Codes• GHOST

– In-house 2D structured multi-block overlapping code

– QUICK scheme for mean flow equations TVD for turbulence equations

– 2nd order backward time stepping

– Incompressible flow solver using SIMPLE approach

– SST turbulence model– MPI parallelization– Well validated for a wide

range of flow conditions.

3 3 3

Computer Codes• UNCLE

– In-house 2-D and 3-D unstructured code

– 2nd order upwind scheme– 2nd order backward time

stepping– Incompressible flow solver

using SIMPLE approach– Domain decomposition using

METIS– SST turbulence model– MPI parallelization– Only validated for a limit

number of cases.

4 4 4

Case 1

• Re =2458

• T = 53.11872

• T = 0.018444 (2880 steps per cycle)

• Average is taken after 5 cycles

• Ensemble averaging - Coarse grid 3 cycle and fine grid 1 cycle

5 5 5

Actuator MotionCase1

Phase(deg)

Disp(m

m)

0 100 200 300-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

Phase(deg)

U/Uref

0 100 200 300-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

0.04

6 6 6

7 7 7

x

y

-20 -10 0 10 20-10

0

10

20

30

v, m/s

y,mm

2 4 6 8 100

5

10

15

20

25

30

35

40

HotwirePIVCoarse GridDense Grid

8 8 8

v, m/s

y,mm

-5 0 5 100

2

4

6

8

10

12

14

16

18

20

Submit dataNew Computation

Frame 001 26 Mar 2004 |

9 9 9

phase, deg

v,m/s

0 100 200 300

-25

-20

-15

-10

-5

0

5

10

15

20

25

30

HotwireCoarse GridDense Grid

X=0 mm, Y=0.1mm

10 10 10

phase, deg

v,m/s

0 100 200 300

0

5

10

15

20

25

30

35

HotwirePIVCoarse GridDense Grid

X=0 mm, Y=2.0mm

11 11 11

12 12 12

13 13 13

14 14 14

15 15 15

Possible Causes• Diaphragm movement vs. piston motion

• 2D vs. 3D– Mass conservation– 3D effects

• Modeling approach

• Inlet velocity shift

• Chamber vs. outflow

16 16 16

Frequency (degree)

Power

0 100 200 300 400101

102

103

104

105

Frequency (degree)

Power

0 100 200 300 40010-1

100

101

102

103

Phase(deg)

Disp(mm)

0 100 200 300-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

Power Spectrum of the ActuatorCase 1

17 17 17

Phase(deg)

Disp(mm)

0 100 200 300-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

360-Degree Phase Waves

18 18 18

Decomposition of 360-Degree Wave

Phase(deg)

Disp(mm)

0 100 200 300-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2