1

Oscillatory Flow Mixing; a review

Malcolm Mackley

Department of Chemical Engineering and Biotechnology

University of Cambridge

June 2010

2

Flow Visualisation

Lightsource

1970s

3

Bristol, 1970 PhD, The Impinging Jet Apparatus

The late Sir Charles Frank and Andrew Keller

4

Bristol, 1976 Post Doc, The Six Roll Mill

Prof Sir Michael Berry

5

Oscillatory Flow Mixing (OFM). Wave Energy devices

Dr Graham Knott

Air turbine generates power

1976-79 Sussex University; Applied Sciences; Material Science Division.

6

Go to wave movie Sussex 1978

7

Phil Trans Roy Soc

8

Chem Eng SciPart 2b project

1980s

9

Oscillation and sharp edges

Go to OFM movie

10

Oscillatory Flow Mixing, (OFM).

Paul Stonestreet 1990

11

Chem Eng SciPart 2b project

12

Chem Eng Sci

Tony Howes

Go to OFM Simulation movie

13

OFM Movie; poetry in motion

Adam Harvey

Go to OFM Harvey movie

14

Heat transfer Chen Eng SciPart 2b project

15

Mass transfer Cheng Eng SciPart 2b project

16

1990s; “Industry will commercialise OFM technology”

1. ICI Wilton, Nylon Monomer. Pilot plant kg /hr for 2 years

2. BP Sunbury Pilot OFM Plant

1990s

17

- Oscillator Base Unit

- Feed inlet section

- Shell and baffled tube vessels

- Product outlet section

Chem Eng Oscillatory Flow Reactor (OFR)

Dr Paul Stonestreet

18

Chem Eng Lab Scale OFR

Paul Stonestreet, Adam Harvey 1999

19Net Flow In

Net FlowOut

Biodiesel Reaction Progressalong Reactor

20

• 0.55 m3 total volume

• Ren=500, Reo=2000

• f= 4 Hz, xo=2.4 cm

• 4 X 150mm tubes @ 3.5m

2 units @ 1.1 m3/hr

Approx 50 tonnes/day

Full-scale OFR reactor

Paul Stonestreet

21

Prof Xiongwei Ni

22

The OFM Meso Reactor

Nuno Reis, Minghzi Zheng

System configuration

Meso tube,diameter d

Smooth constrictions: spacing 3dMinimum constriction diameter 0.4d

Scale- down

2000s

23

45º

35 mm, V 4.5 mL

45º

35 mm, V 4.5 mL

a)

b)

L

d d0

24

The meso-tube and dimensionless groups

• Geometry

d=5.0 mm, λ=15.2 mm, h=1.6 mm, δ=6.4 mm, β≈45o

• Governing dimensionless groups

dfxo

o2

Re Oscillatory Reynolds number

Strouhal numberox

dSt

4

Net flow Reynolds numberdU

n Re

Smooth Periodic Constrictions Oscillatory flow Meso-Reactor

Fluid oscillation Reynolds number

The ratio of tube diameter to amplitude

Fluid net flow Reynolds number

h

d

25

Experimental and ModellingExperiment setup Numerical Modelling

Particle Imaging velocimetry (PIV) system

Phase position for an oscillation cycle

Phase position

0 1

2

3 4 5

6

7 8

X0

The 3-D hexahedral mesh for simulation (Fluent®)

4)()(

2Dtutm

•Periodic boundary condition

u( t) 2fx0 cos(2ft)

26

Meso Fluid Mechanics

Minghzi Zheng

Go to OFM PIV movie

Go to OFM LES movie

27

Chem EngLab Meso Reactor

28

RTD experiment set-up

Probe3

Probe1

Dye Injection

Probe2

29

Dispersion model

Z

C

Z

C

uL

DC

2

2

Governing equation Imperfect injection method; numerical fitting

0)(

)()(

dttc

tctC

2

31

/4exp

4 t

t

Pe

t

PetTR

t

dppCptTRtC0 12 )('

2

122 '

N

iiiC tCtC

uL

D

30

Model fitting • Net flow with oscillation

• Ren=58, Reo=312, St=0.4

Net flow without oscillation

Ren=58,Reo=0

0 200 400 600 800 1000 12000

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

Time (s)

C(t

) (-

)

(a)

Probe 1

Probe 2

Probe 3

Exp-C(t)1

Exp-C(t)2

Exp-C(t)3

Fit-C(t)3 ' (2->3)

0 100 200 300 400 500 600 700 800 9000

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

Time (s)

E(t

) (-

)

b) Exp-E(t)1

Exp-E(t)2

Exp-E(t)3

Fit-E(t)2 (1->2)

Fit-E(t)3 (1->3)

Fit-E(t)3 (2->3)

31

Liquid-liquid dispersion

Silicon oil (4.6mPas,2.5%) mixing with water at xo=2 mm

Silicon oil (4.6mPas, 2.5%) mixing with water at f=6Hz

a) f=6Hz

b) f=10Hz

a) xo=3 mm

b) xo=4 mm

32

Particles in suspension

Instantaneous velocity vector maps of fluid phase at Reo = 625, x0 = 2 mm, f = 10.0 Hz at vertical position in the presence of 3% (v/v ) amount of ion-exchange particles

33

And finally;The BT 1000

Go to BT 1000 movie

34

The BT 1000

35

What went right with OFM invention.

The science was a lot of fun

What went wrong.

Lack of focus in pushing the technology

36

Acknowledgments.A cast of many;

In particular,

Part 2B StudentsPostgraduatesPostdoctorates

Chem Eng support staffBob Skelton

“The Department”“For allowing me the freedom to develop speculative ideas”

Thank you!