Isothermal magnetic Bernoulli integral
= Isothermal magnetic Bernoulli integral
{title2=$\epsilon(\psi)$}
In aligned steady ideal flow with $p=c_s^2\rho$ and constant <isothermal sound speed>, the <Lorentz force density> has no field-parallel component. Projecting momentum along the <magnetic field> makes $u^2/2+\Phi+c_s^2\ln(\rho/\rho_0)$ constant on each connected magnetic surface. The arbitrary reference density changes only the additive constant.