isentropic-flow-relationslisted

# Isentropic Flow Relations (aerodynamics/high-speed/isentropic-flow-relations) Use when you must convert a Mach number into the isentropic total to static ratios of a compressible flow, recover the Mach number from a given area ratio on both branches of the area-Mach relation, or compute the choked mass flow a passage passes at its sonic throat. This leaf implements the standard isentropic relations for a perfect gas at gamma 1.4 (air, R = 287.0) in pure Python, stdlib only: the total temperature, total pressure and total density ratios from a Mach number, the total condition rebuild from a static state, the subsonic and supersonic roots of the area-Mach relation by deterministic bisection, and the choked mass flow through the mass flow parameter. It pairs with the high-speed pack leaves for the neighboring non-isentropic mechanisms: normal-shock for the state change across a shock, prandtl-meyer for expansion fans, and shock-expansion-airfoil for the patched airfoil solution. It does not compute shock or fan state changes, pitot pressure behind a shock, compressibility corrections, or nozzle throat sizing and thrust; those belong to the sibling leaves below. ## Domain quick reference - Total temperature ratio: T0/T = 1 + (gamma - 1)/2 * M^2, from the energy equation at gamma 1.4: T0/T = 1 + 0.2 * M^2. - Total pressure and density ratios from the isentropic exponents: p0/p = (T0/T)^(gamma/(gamma - 1)) = (T0/T)^3.5 and rho0/rho = (T0/T)^(1/(gamma - 1)) = (T0/T)^2.5 a