Pulse Detonation Studies in Japan (2007)

Toshi FujiwaraNagoya University and FF Lab

Experimental Setup for Pulse Detonation Turbine Engine [3, 4]

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

0 5 1 0 1 5 2 0 2 5 3 0

TIP

[kP

a] TIT

[K]

T im e [s e c ]

T IT

T IP

Turbine Inlet Pressure and Temperature for Hydrogen-Air 20Hz Operation

Experimental Device of PDTE Using a Single-Cylinder PDE

Influence of Shock Diffuser: Pressure History at Turbine Inlet

Thermal Efficiency Measured by Single-Cylinder PDTE

Four-Cylinder PDE Developed for PDTE

Fuel H2Oxidizer AirFrequency 20, 50, 60, 70, 80 Hz

Equivalence ratio 1.34, 1,45,1.56, 1.68, 1.79Flow rate 12.8 ℓ/s

contraciton ratio 1.9expantion ratio 4.1

HH22HH22OxidOxid--izerizer Amplifier

Ignition system

Solenoid Valves

Schelkin Spiral

Pressure transducers

Spark plugInjectors

Inner diameter : 15 mm

Tube length : 660 mm

Schematic of Micro PDE and Experimental conditions

1500

1600

1700

1800

1900

2000

2100

2200

1.0 1.2 1.4 1.6 1.8 2.0Equivalence ratio

Velocity, m/s

: C-J condition

: 20 Hz operation

: 50 Hz operation

: 80 Hz operation

Combustion Wave Propagating Velocities versus Equivalence Ratio for Various Frequencies

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

1 8 0

0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 1 8 0

IS P fro m s id e w a ll p ressu re h is to ry

L /D

Sp

ecif

ic I

mp

uls

e, s

E n d o -F u jiw a ra 2 n d th eo ry (8 )

1 1 /1 2

E n d o�fs P D E (7 )K a sa h a ra ’s P D E (7 )

IS P fro m c lo sed en d w a ll p re ssu re h is to ry

Specific impulses versus L/D

50

45Pressure transducer

A B

Detonator Image area (30×42)

13

10

10

Spark plug

50

Short Multiple Tubes Attached Right behind Spark Plug

0 200 400 600 800 1000 1200 1400

DDT distance (mm)

Min. Max.

4.4L50

No detonator

14L50

7.2L50

7.2L25

7.2L50*

7.2L50**

7.2L50 7.2L50* 7.2L50**

Influence of Multiple Tubes Geometry on DDT Distance

70 80 90 100 110 120

250

300

350

Shock Flame Detonation

Distance (mm)

Tim

e (

s)

7.2 L25

7.2 L50

4.4 L50

transition

transition

no transition

720 m/s

790 m/s440 m/s

2900 m/s

2960 m/s

830 m/s1000 m/s

520 m/s

7.2 L507.2 L25

4.4 L50

x-t Diagrams of Shock Waves, Flames and Detonation Fronts

3 m m

1 5 m m

3mm

40m

m

34m

m

3 m m 1 5 m m

(a) Rifle Groove and (b) Shchelkin Wire

2000

2200

2400

2600

2800

3000

600 700 800 900 1000 1100Distance from spark plug [mm]

Prop

agat

ion

velo

city

[m/s]

Shchelkin spiral 500mm

Rifle Detonation Tube 500mm

C-J detonation

Gas mixture�2H2-O2

Initial pressure�70kPa

Comparison between Rifle Groove and Shchelkin Wire

Schematic of Perpendicular Predetonator

Importance of Overflowed Volume for Direct Initiation

( a )

( c )

3 0 a t m 7 0 a t m3 0 a t m 7 0 a t m

( d )

m m0 0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 3 .5 4 .0 m m0 0 .5 1 .0 1 .5 2 .0 2 .5 3 .0 3 .5 4 .0

( b )

0

0 .5

0

0 .5

S l a p p i n g W a v e

Computed Smoke-foil Records. (a) 2-D Results, (b) 3-D Results for “Rectangular Mode in Phase”, (c) 3-D Results for “Rectangular Mode Partially out of Phase”, (d) 3-D Results for “Diagonal Mode”

Time,s

4.74PropagationDirection

1

2

3Sidewall

Lowerwall

4

2

Pressure-Space Isosurface and Contours in front of and behind Detonation for “Rectangular Mode in Phase”

Time,s

4.16 PropagationDirection

21

Sidewall

Lowerwall

2

Pressure-Space Isosurface and Contours in front of and behind Detonation for Diagonal Mode

Pressure History on Closed End of PDE with Fully-filled Combustible Mixture

Impulse per Cycle and Fuel-based Impulse for Partially-filled PDE

Mixture-based Impulse for Partially-filled PDE: Ethylene-fuel