** Force/Power
optimization**by Evgenij Barsoukov

*Courtesy of Evgenij
Barsoukov
*Created on April 30, 2002 -

__The original
document can be found at__** : ****http://sudy_zhenja.tripod.com/lifter_theory/Force.htm**** **

__Force/Power
optimization__

**Using derived above equations for
current/thrust and current/voltage relation it is possible to
tackle the main problem - how to improve thrust/power ration of a
lifter to make it a more attractive flying device compared to
conventional once. How would thrust/power ratio change if we
adjust voltage, distance wire/collector, and wire radius? Results
are shown below.**

**Used equations (see derivation at ****lftheory.htm#eqn****
):**

**Thrust/current :**

**Current/voltage**

**Here :**

**And values of parameter used in calculation are :**

**1. **__Voltage optimization__

**Voltage
was calculated for 100 points from minimal corona initiation
voltage (6.9kV) calculated by Peek's equation for given distance,
until voltage 100kV.**

**Note that
spark discharge might occur before 100kV.**

**Here is
resulting Thrust (in gram)/Power (in W) relation**

**..and
Thrust/Voltage relation**

**As you
could expect, thrust is increasing with voltage, however the
efficiency (thrust/power) is decreasing rapidly from maximal 3
g/W to very small values.**

**2. **__Wire/collector
distance optimization__

**Thrust is
calculated by changing d from 30mm to 1m**

**Resulting
Thrust/Power ration is shown below :**

**Exciting result is that thrust/power relation is
increasing proportionally with distance and can reach huge values
as 40 gm/W! However, absolute thrust is rapidly decreasing with
distance as can be seen below :**

**Nevertheless, absolute thrust can be increased by
increasing the length of wire/collector. Therefore increasing
distance gives clear way of almost unrestricted efficiency
increase. **

**3. **__Corona wire radius
optimization__

**Radius was
changed from gauge 50 (0.015 mm) to gauge 20 (1.5mm). Resulting
thrust/power relation is given below :**

**It is great to see, that efficiency does not change,
but thrust does! See below absolute thrust/radius dependence :**

**With decreasing radius thrust
increases a lot, without losing efficiency! **

**Increasing the wire/collector distance by simultaneous increase of wire/collector lenght can allow to achieve****thrust/power ratios up to 40g/W****.****Decreasing wire radius increases thrust without degrading thrust/power ratio.**

**See also : ****Lifter theory proposal****
****by Evgenij Barsoukov**

Even
if, in the worst case, a fluid medium is required (EHD)
for the Lifter hovering, this technology is an excellent
starting point for building highly
manoeuvrable VTOL crafts which will flight silently
without moving parts... Jean-Louis
Naudin - April 30, 2002 |

**Return to the**** ****Lifters experiments**** ****page**