Semi‑analytical Scramjet Method
ASME Journals highlighted a semi‑analytical method for scramjet combustor design using a thermally‑perfect gas model—an approach that can streamline early design and optimization of hypersonic propulsion systems. The work offers a computationally cheaper path for preliminary combustor sizing and performance trade studies. (x.com)
Paper authored by Biswadip Shome, published online December 18, 2025 and appearing in J. Thermal Sci. Eng. Appl., Vol. 18, No. 3 (Mar 2026), Paper No. TSEA‑25‑1435 (10 pages), DOI 10.1115/1.4070222. (asmedigitalcollection.asme.org) The method models a calorically imperfect but thermally perfect gas and formulates the coupled effects of variable area, friction, and heat addition to predict Mach number, static pressure, and temperature in an isolator‑combustor geometry. (asmedigitalcollection.asme.org) Validation cases used a hydrogen‑fueled scramjet combustor at inlet Mach 2, 4, and 6 with an equivalence ratio of 0.30, and the semi‑analytical predictions matched CFD results to within 3.1% for Mach, pressure, and temperature. (asmedigitalcollection.asme.org) The paper reports that omitting thermally‑perfect gas effects produces up to a 14% error in Mach number and up to a 21% error in temperature at an inlet Mach of 6, highlighting nonnegligible thermal property variation at higher speeds. (asmedigitalcollection.asme.org) An optimization driven by the semi‑analytical formulation adjusted combustor exit height and achieved a near‑zero static pressure loss in the combustor, demonstrating an application-level design change reported in the study. (asmedigitalcollection.asme.org) The authors position the semi‑analytical approach for preliminary conceptual design and multi‑concept trade studies as an alternative to repeated CFD runs or physical tests during early sizing, supported by the paper’s comparisons and optimization examples. (asmedigitalcollection.asme.org)
