Mika EDAHIRO, Akiko MATSUO, Tatsushi ISONO, Masahiro TAKAHASHI, Sadatake TOMIOKA
DOI Number: N/A
Conference number: HiSST-2025-009
Turbine-based combined cycle (TBCC) engine represents one of the most promising propulsion technologies capable of sustained hypersonic flight. To achieve optimal thrust generation across the entire flight envelope, it is crucial to optimize the TBCC nozzle geometry, which directly governs both thrust and lift generation. This study examined the influence of direct turbo-ramjet to scramjet flow path integration on the scramjet’s propulsive performance at cruising speeds, specifically in the absence of any variable mechanisms such as sliding plates or variable splitter to regulate the flow distribution between the two passages. The computational domain was based on the Single Expansion ramp nozzle (SERN) configuration, employing a scramjet’s nozzle inlet height of 163 mm and a length of 3058 mm, while investigating four cases involving cowl to turbo-ramjet flow path distances ranging from 220 mm to 820 mm. The inflow into the nozzle originates exclusively from the scramjet inlet, characterized by a Mach number 1.97, the static pressure of 103.7 kPa, and a static temperature of 2518 K. The two-dimensional compressible Navier-Stokes equation was adopted as the governing equation for the numerical analysis. The result revealed a thrust reduction of 2.3 % for the 820 mm configuration, the case corresponding to the most downstream integration point with the turbo-ramjet flow path, when
compared with the baseline SERN configuration.