Transcript STAIF2006_Presentati..

Experimental Study of the Machian Mass
Fluctuation Effect Using a µN Thrust Balance
N. Buldrini, K. Marhold, B. Seifert and M. Tajmar
Space Propulsion – ARC Seibersdorf Research
[email protected]
Machian Mass Fluctuations
1
2
Impulse Term
Exotic Mass
Generator term
Always negative!
Machian Mass Fluctuations
Mass Fluctuation in a Capacitor
Delivered Power
≈
Capacitor Volume
Mass Fluctuations for Propulsion
Ballast
Mass
Fluctuating
Mass
What if you can make the mass of a capacitor
fluctuating and act on it in a direction when it is heavier
and in the opposite direction when it is lighter?
Machian Mass Fluctuations
The Devices
Actuator
(piezoelectric
material)
Thrust
Capacitor
Ballast
Mass
~
Power Supply
Machian Mass Fluctuations
The Devices
Coil
~
Capacitor
~
Electric
Field
Power Supply
The “Flux Capacitor”
Magnetic
Field
Force
Machian Mass Fluctuations
The Devices
F
E
B
The Tested Devices
E
B
Thrust
Mach-5C
Direction
Capacitors are
Mach-6C
under the coil
Claimed Thrust:
Claimed Thrust:
~ 30 μN
100-200 μN
The Tested Devices
The Experimental Setup
Vacuum Chamber and Thrust Balance
Thrust Balance arrangement inside
the Chamber. Balance succesfully
tested with In-FEEP thrusters!
Device
Pivot
Vacuum Chamber used for testing
Material: Stainless Steel
Vacuum: 10-6 mbar
Sensor Assmbly
The Experimental Setup
Device Arrangement on the Balance
The Experimental Setup
Thrust Balance
Device Mounted on the Balance
The Experimental Setup
Thrust Balance
C-Flex G-10
Flexural Pivots
Thrust Balance Pivot
and Device Feeding Cables
The Experimental Setup
Thrust Balance
Optic Sensor Detail
Optic Sensor and Damping
Actuator Assemblies
The Experimental Setup
Thrust Balance
Philtec D64 Fiber Optic
Displacement Sensor
• Principle: Measures the reflection of light
• Only fiber optic parts in the vacuum chamber (no EMI)
• Noise: 0.008 µm (DC-100Hz)
The Experimental Setup
Device Wiring Schematics
Same setup used by Woodward and March. Amplifiers from
March and original step-up transfomers from Woodward.
Experimental Results
Mach-5C
This kind of behaviour
indicates the presence
of thermal effects on
the feeding wires
Experimental Results
Mach-5C
Predicted thrust at 90°
phase shift between
capacitor voltage and
coil current: ~ 5µN
Zero thrust predicted
at 180° phase shift
Thermal drift is still
present.
Experimental Results
Mach-6C
- Capacitor Power
- Coil Power
- Thrust Trace
Cap.voltage: 3.2 kVp
Coil Field: 250 Gauss
Frequency: 52 kHz
Cap.V / Coil I - Phase
Relationship: 90deg
Expect. Thrust: ~150µN
The thermal drift has been reduced re-arranging the wiring and
reducing the firing time to 2 seconds
Experimental Results
Mach-6C
50µN Pulse
Superimposed
Cap.voltage: 2.5 kVp
Coil Field: 200 Gauss
Frequency: 55 kHz
Cap.V / Coil I - Phase
Relationship: 270deg
Expect. Thrust: ~50µN
- Capacitor Power
- Coil Power
- Thrust Trace
A pulse of 50µN was generated during the firing time by the
calibration actuator, to test the response of the balance
Experimental Results
Balance Response to Short Pulses
A series of short pulses was generated using the calibration actuator, to
evaluate the balance response at different thrust/pulse duration values
Experimental Results
Mach-6C
Mach-6C was sent back to
Woodward to be tested again
Then the device was sent back
again to ARC-sr
Tests in air by Woodward showed
a thrust effect possibily due to an
electromagnetic interaction.
The device has been then potted,
and tested in vacuum. A residual
thrust of 100-200µN was recorded
Experimental Results
Mach-6C Potted
Cap.voltage: 3 kVp
Coil Field: 200 Gauss
Frequency: 52 kHz
Cap.V / Coil I - Phase
Relationship: 270deg
Expect. Thrust: ~75µN
The phase relationship is changing during firing time, expecially at high capacitor
power levels. Two calibration pulses of 50µN were generated with duration of 0.8
and 0.5 seconds to test the response of the balance in case of shorter thrust events
Experimental Results
Mach-6C Potted
Capacitor + Coil
Energized together
Only Capacitor
Energized
Experimental Results
Mach-6C Potted
Only Capacitor
Energized (Shielded Cable)
Only Capacitor
Energized
Experimental Results
Test at Higher Frequency / Different Dielectric
Dielectric: Titanium Oxide
Series Tank Circuit
Self-contained Device
Voltage: 2.3 kVp
Frequency: 2 MHz
Expected Thurst: 1 ÷ 6 mN
No thrust was detected within the sensibility
of the used electronic balance (0.1mN)
Conclusions and recommendations
• Mach thrusters, tested by Woodward, were characterized using
highly sensitive µN thrust balance used for electric propulsion
• Our measurements rule out a thrust above 50% of the theoretical
predictions and previous claims. It is likely, that this threshold is even
reduced to 10% as indicated by part of our data.
• A device operating at higher frequencies and with different dielectric
was designed and built at ARC-sr. No thrust of the magnitude
predicted by the models developed by Woodward/March/Palfreyman
was observed
• An upgrade of the sensor setup presently used by Woodward/March
to a torsion balance or a ballistic pendulum setup is recommended
• Due to the difficulties in keeping the right phase relationship between
E and B fields, and thus same operating conditions, the development
of a device based on a tank design is recommended
• The development of a self-contained device similar to the one built at
ARC-sr is proposed as well, using barium titanate as dielectric