Skylon Aerospace Plane and Its Aerodynamics and Plumes

The Skylon concept incorporates the highly innovative synergetic air-breathing rocket engine concept that has the potential to revolutionize the mode of propulsion for transportation of medium-weight payloads to low Earth orbits. An independent partial assessment is provided of the technical viability of the Skylon concept. Pressure lift and drag coefficients derived from Euler simulations for unpowered flight compare very well and fairly well, respectively, with those from engineering methods. The engineering-method coefficients for powered flight are increasingly less acceptable as the freestream Mach number is increased beyond 8.5 because these methods did not account for the increasing favorable (in terms of pressure forces) effect of underexpanded rocket engine plumes on the aft fuselage. At Mach numbers greater than 8.5, the thermal environment around the aft fuselage is a known unknown: a potential design and/or performance risk issue. The adverse effects of shock waves on the aft fuselage and plum...