Detonation interaction with a diffuse interface and subsequent chemical reaction
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Citations
Modes of Detonation Wave Propagation in Water Vapor Concentration Gradients
Modeling detonation limits for arbitrary non-uniform concentration distributions in fuel–air mixtures
Diaphragm effect on the detonation wave transmission across the interface between two mixtures
Numerical investigation of self-sustaining modes of 2D planar detonations under concentration gradients in hydrogen–oxygen mixtures
Proposed Vertical Expansion Tunnel
References
Elements of gasdynamics
On errors of digital particle image velocimetry
Turbulent Free Shear Layer Mixing and Combustion
Experiments on the Richtmyer-Meshkov instability of an air/SF 6 interface
Turbulent free shear layer mixing and combustion
Related Papers (5)
Behavior of detonation propagation in mixtures with concentration gradients
Detonation propagation in hydrogen-air mixtures with transverse concentration gradients
Frequently Asked Questions (15)
Q2. What is the effect of the shear layer displacement thickness on the surrounding fluid?
the shear layer displacement thickness changes from being negative to positive causing the surrounding fluid to be displaced and generating compression waves.
Q3. How many impulses are used to calculate the increment?
A reference impulse of 1000 kg·m−1·s−1 obtained from impulse measurements at pressure transducer P4 is used to calculate the increment.
Q4. What is the main consequence of the mixture composition gradient through the diffuse interface?
The main consequence of the mixture composition gradient through the diffuse interface was to cause the detonation wave to curve: eventually the reaction zone decouples from the leading shock wave when the combustible mixture becomes sufficiently dilute.
Q5. What is the effect of the curved wave on the reaction zone structure?
For a detonation modeled as an ideal one-dimensional discontinuity with no affect of curvature on reaction zone structure, the normal component of the curved wave will correspond to the local Chapman-Jouguet detonation velocity.
Q6. What is the purpose of the sliding valve?
The sliding valve, actuated by a falling mass, was designed to completely isolate both the combustible mixture and test gas, as well as to open sufficiently fast to control the formation of the gravity current.
Q7. What is the effect of the rapid increase in induction time with decrease in shock velocity?
The rapid increase in induction time withdecrease in shock velocity results in the decoupling of the reaction zone from the shock and the formation of a gap between the transmitted shock and the turbulent mixing zone.
Q8. How did the authors measure the effects of combustion in the turbulent mixing zone?
By using a fuel-rich ethylene-oxygen combustible mixture and an oxidizing test gas, the authors were able to observe and quantify the effects of combustion inside the turbulent mixing zone.
Q9. What is the effect of the vorticity thickness of the interface?
It is evident that the vorticity thickness of the interface is not uniform and exhibits a sinuous shape as a result of the turbulent flow structure present at the interface.
Q10. What is the color of the ethylene-oxygen combustible mixture?
In these experiments the φ = 2.5 ethylene-oxygen combustible mixture is colored yellow for visibility and flows below the less dense nitrogen gas.
Q11. What is the effect of a curved detonation wave on the reaction zone?
When the detonation propagation direction is perpendicular to the mixture gradient, a curved detonation wave results that ultimately decouples into a shock wave and turbulent mixing zone (TMZ), shown in Fig. 1b.
Q12. What is the constant of proportionality C?
The constant of proportionality C is varied from a value of 1 to 10 to account for interface growth after the shock reflection off the end-wall.
Q13. What is the velocity of the left (u+p) edges of the fluid element?
The velocity of the left (δu−p ) and right (δu+p ) edges of the fluid element are combined to obtain an expression for the growth rate of the fluid elementdx∗ dt = δu + p −δu−p .
Q14. What was the optical viewport used for the experiments?
Visualization for the experiments, using a schlieren system [1], was made through an optical viewport (BK7 or quartz windows) that could be arranged in two separate positions.
Q15. What are the details of the interaction between the detonation and the interface?
The details of this interaction are dependenton the mixture compositions, the relative geometry of the detonation and interface, and the characteristic thickness of the interface.