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Combustion waves in hydraulically resisted systems.
I Brailovsky1, L Kagan, G Sivashinsky
1School of Mathematical Sciences, Department of Applied Mathematics, Tel Aviv University, Tel Aviv 69978, Israel.
Summary
Hydraulic resistance in confined explosives creates a new pressure diffusion mechanism for rapid reaction spread. This phenomenon influences detonation regimes and transitions, impacting combustion behavior in obstructed channels.
Area of Science:
- Combustion science
- Chemical engineering
- Fluid dynamics
Background:
- Confined explosives exhibit complex burning behaviors influenced by geometry.
- Hydraulic resistance is a key factor in reaction spread and propagation modes.
- Understanding transitions from deflagration to detonation is crucial for safety and performance.
Purpose of the Study:
- To investigate the impact of hydraulic resistance on explosive burning.
- To elucidate the mechanism of reaction spread, including pressure diffusion.
- To analyze combustion transitions in obstructed channels, particularly open-ended configurations.
Main Methods:
- Review of recent research on hydraulic resistance effects.
- Development and application of a quasi-one-dimensional Fanno-type combustion model.
- Analysis of premixed gas combustion in obstructed channels.
Main Results:
- Hydraulic resistance induces pressure diffusion, enabling fast subsonic and supersonic propagation.
- It influences detonation regimes and transitions from slow to fast burning.
- In open-ended channels, hydraulic resistance causes preheating and autoignition, triggering deflagration-to-detonation transition (DDT).
- Open-end ignition hinders DDT compared to closed-end configurations.
Conclusions:
- Hydraulic resistance is a critical factor governing explosive combustion dynamics.
- Pressure diffusion is a significant mechanism for reaction spread.
- The Fanno-type model provides insights into DDT in obstructed channels, with open-end configurations presenting unique challenges.
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