Table 2.

Comparison of analytical expressions from state of the art and our work.

	state of the art	current work	comparison
current flux	$J={\displaystyle \frac{9{\mu }_b\epsilon {(\phi )}^{2^{\phantom{\int }}}}{8d^3}}$ Mott–Gurney law [28]	$J={\displaystyle \frac{9{\mu }_b\epsilon {(\phi -{\phi }_o)}^2}{8x^3}}$	current flux at any x; model accounts for ionization onset—φ0
voltage–current characteristics	$I=C\phi (\phi -{\phi }_o)$ Townsend relation [29]	$I={\displaystyle \frac{9{\mu }_b\epsilon {(\phi -{\phi }_o)}^{2^{\phantom{\int }}}}{8L_c^2}}$	length scale Lc provides a physical interpretation to fitting constant—C
voltage–force characteristics	$F_{\mathrm{EHD}}={\displaystyle \frac{C\phi (\phi -{\phi }_o)d}{{\mu }_b}}$	$F_{\mathrm{EHD}}={\displaystyle \frac{9\epsilon {(\phi -{\phi }_o)}^{2^{\phantom{\int }}}d}{8L_c^2}}$	Coulombic force is computed from the first principles
voltage–thrust characteristics	no expression	$T=(1-\theta )F_{\mathrm{EHD}}$	model computes thrust and accounts for aerodynamic losses via parameter $\theta$