Rocket Nozzle Divergence Loss (propulsion/rocket/rocket-nozzle-divergence-loss)

Use when you must compute the rocket-nozzle-divergence-loss bookkeeping from the nozzle geometry and the ideal attached-flow state: apply the conical divergence factor lambda = (1 + cos(alpha))/2 for the half-angle to the ideal axial momentum thrust, or the bell contour efficiency (0.98 typical for the 80-percent bell) in its place; grow the turbulent boundary layer over the divergent length to the displacement thickness and convert it with the 1-D mass-flux correction to the momentum loss fraction; assemble the delivered thrust from the loss-corrected momentum term and the unchanged pressure term. Produces the shape factor, the loss fraction, the effective exit area rati…