V² scaling
UntestedSame Gravitor, different voltages. Thrust should scale with V².
What this test isolates
Premise. Coulomb's force scales with E² = (V/d)² for fixed gap. Doubling voltage should quadruple thrust.
Why it matters. If thrust is ion-wind or thermal, V² won't fit cleanly — there's a velocity-saturation knee. A clean V² fit through ≥3 voltages is the strongest single confirmation that the force is electrostatic.
Formula. F = α · ½ε₀(V/d)² · (κ−1)/κ · A
Variable. Applied voltage (V), all other parameters held constant
Hold constant
- Same Gravitor (same emitter / dielectric / ground plate / spacing)
- Same atmosphere — temperature and humidity within ±2°C / ±5% RH
- Same scale, same orientation, same warmup time
Prediction. Thrust ratio between two voltages equals the square of the voltage ratio: F₂ / F₁ = (V₂ / V₁)².
How to run this test
- 1
Pick a voltage ladder
Choose 3–5 evenly-spaced voltages well below the dielectric's safe ceiling. Common sweep: 10, 15, 20, 25 kV.
- 2
Stage the rig
Mount the Gravitor on the scale, faraday cage closed, scale tared with HV off. Capture a 30-second baseline.
- 3
Run each voltage
Bring HV up smoothly to setpoint, hold for 30 s, record the steady-state weight change, drop voltage, wait for the scale to recenter, repeat.
- 4
Log all five fields
Voltage (kV), steady-state Δm (g), ambient T/RH, runtime, any visible corona / smell. The thrust prediction needs voltage and Δm; the rest qualifies the run.
- 5
Repeat with a different Gravitor
Confirm the V² law on multiple geometries. A single Gravitor scaling cleanly is encouraging; three different ones agreeing is conclusive.
Pitfalls
- !Going above 70% of dielectric breakdown — partial discharge skews the curve.
- !Letting the scale drift between trials — re-tare every set or use the persistent zero feature.
- !Running too long — heating warps the dielectric and the result drifts.