Altitude compensation and oscillation suppression performance of slotted expansive deflection nozzles
Year: 2026
Type: article
Abstract: Cold-flow experiments are conducted on a newly proposed planar Slotted Expansion-Deflection (ED-Slit) nozzle and a conventional planar ED nozzle to evaluate thrust compensation capability and shock oscillation suppression. A controlled total pressure trajectory, involving a rapid rise followed by a gradual fall, is implemented to emulate nozzle operation during ascent and descent. Schlieren imaging and wall-mounted pressure transducers are employed to capture flow structures and pressure oscillations. The results show that the slotted structure induces inward air entrainment and separation shock formation when the supersonic stream covers the inner wall, while promoting outward air ejection downstream of the separation shock. These mechanisms accelerate the onset of flow separation, increase downstream wall pressure, and modify mode transition dynamics. Compared with the conventional ED nozzle, the ED-Slit configuration achieves a 3.04% increase in total impulse and reduces wall pressure oscillation amplitude by 26.2%. The findings demonstrate that the proposed nozzle not only enhances thrust compensation but also provides passive control of unsteady shock behavior, offering a valuable guidance for the engineering application and optimization of ED nozzles.
Source: Chinese Journal of Aeronautics
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,000
OpenAlex ID: W7139055471