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Updated: Aug 7, 2026
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Preparation of Free-Surface Hyperbolic Water Vortices
Published on: July 28, 2023
High-pressure-ratio vacuum sealing by a perturbed free-vortex aerodynamic window
Hiroshi Imao1, Kazumasa Takahashi2, Yasuto Miyake1
1RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan.
The Review of Scientific Instruments
|August 6, 2026
Summary
Researchers enhanced aerodynamic window sealing pressure ratios by perturbing the free-vortex flow. This novel approach significantly boosts performance for vacuum sealing applications, achieving pressure ratios up to 200.
Area of Science:
- Fluid Dynamics
- Vacuum Technology
- Aerodynamic Engineering
Background:
- Conventional free-vortex aerodynamic windows have limitations in sealing pressure ratio.
- Optimizing flow conditions is crucial for enhancing vacuum sealing capabilities.
Purpose of the Study:
- To investigate a perturbed free-vortex operating concept for aerodynamic windows.
- To enhance the sealing pressure ratio (phigh/plow) beyond conventional matched conditions.
- To assess the concept's applicability to various gases and multistage configurations.
Main Methods:
- Designed, fabricated, and tested a compact free-vortex aerodynamic window assembly.
- Operated the system under low-gas-flow-rate conditions with sub-atmospheric supply plenum pressure.
- Utilized computational fluid dynamics (CFD) for simulations and validated against experimental data.
- Conducted measurements with Argon (Ar) and Helium (He) and evaluated two-stage configurations.
Main Results:
- Perturbed free-vortex operation increased the pressure ratio from approximately 5 to up to 200.
- CFD simulations showed good agreement with experimental pressure ratios and distributions.
- The concept demonstrated extendability to other gases (Ar, He) and multistage configurations.
- An estimated overall pressure ratio of about 4550 was achieved for a two-stage configuration.
Conclusions:
- Perturbed free-vortex operation significantly enhances sealing pressure ratios in low-gas-flow regimes.
- This approach offers a promising solution for high-pressure-ratio vacuum sealing applications.
- The findings are relevant for accelerator gas targets, gas strippers, and other vacuum systems.
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