Hi Michel, > ... > > My guess is that the potential needs to be increased proportional to the > > vacuum. So if you double the vacuum, you need to double the potential. > ... > > Multiply it by root 2 in fact. To maintain the same thrust, every time you > halve the pressure you must double the current, as per the thrust formula > I*d/mu where ion mobility mu is doubled (inversely proportional to air > density). In order to double the current you must indeed increase voltage, > but not by a factor two, only root 2 as the I(V) law is quadratic for a > corona discharge.
Thanks, I wasn't aware of this reasoning. So the question stands for Kyle, was the vacuum experiment properly conducted? Also, for you Michel, why does the ion mobility equation necessarily interpret as being ion wind? Why can't the force term refer to the force between the ions on the lifter and the electrostatic dipoles in the space surrounding it? Dave
