Unified Continuous Propulsion from Rest to Hypersonic Flight
A Conceptual Framework Based on Continuous Catalytic-Atmospheric Oxidizer Transition and Oblate Combustion Geometry
Correction notice — version 3
Equation (5) of versions 1 and 2.2 carried an incorrect sign in the radicand. The membrane stress of a pressurized oblate ellipsoidal shell varies as 1/√(1 − ε²sin²θ), not 1/√(1 + ε²sin²θ). The error was identified by the author through independent numerical verification against classical thin-shell theory and is corrected at the author's initiative.
Five statements of Sections 4 and 5 depended on the erroneous form and are withdrawn: the quasi-uniform stress distribution claim; the interior optimum in eccentricity derived from Equation (5); the 18–25 % area-to-volume advantage over an equivalent-volume cylinder; the wall-thickening penalty attributed to cylindrical geometry; and the derived 40–50 % structural mass reduction. Also withdrawn is the statement that peak-stress reduction had been verified through coupled CFD-FEM analysis.
The HEC principle and Equation (2) are unaffected. The geometric optimization of the chamber remains under continuing evaluation and continues to be the subject of the corresponding patent application. Section 11 of version 3 records the erratum in citable form. The companion method paper (10.31224/7957) is not affected.
Abstract
The unification of propulsion across the full Mach 0 to Mach 12 envelope within a single engine architecture has remained an open problem in aerospace engineering for over seven decades. Existing combined-cycle approaches (TBCC, RBCC) rely on discrete mode-switching between specialized propulsion units, incurring thrust losses of 10 to 25 percent during transition windows and imposing substantial structural and operational penalties.
This paper presents a conceptual framework for unified continuous propulsion based on two integrated principles: (i) continuous transition of oxidizer source from catalytically-decomposed hydrogen peroxide to atmospheric air, governed by a smooth monotonic function of Mach number, and (ii) oblate ellipsoidal combustion chamber geometry that accommodates radial catalytic gradient distribution and a continuous chamber-to-nozzle transition.
The synergistic integration of these two principles is shown qualitatively to enable continuous operation from static thrust through hypersonic regimes without mode-switching, with improved thermal management compared to cylindrical alternatives.