Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

Abstract

The three-dimensional premixed H 2 -O 2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space-time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed.

A three-dimensional discrete Boltzmann model for steady and unsteady detonation

“…Shen et al [32] found that with the duct width decreasing, the rectangular out-ofphase can be obtained with a rectangular initial perturbation. Therefore, we decrease the grid size to N x × N y × N z = 600 × 160 × 160 to find out whether the rectangular out-of-phase can be observed.…”

“…Dou et al [26], Wang et al [27] and Borisov et al [28] adopted the fifth-order weighted essentially non-oscillatory method to conduct a high resolution simulation of 3D detonations and study the influence of different factors (e.g., tube width, specific heat ratio and initial perturbation) on the structure of detonation waves. In addition, different mathematic models have been developed to solve the reactive Euler equations for the purpose of reducing the memory usage and computational time [29,30,31,32,33].…”

Acoustic characteristics of pulse detonation engine with ellipsoidal reflector

“…The radius of fuel droplets is 50 µm. [20] In order to simulate the initial ignition spark, 15 ambient pressures and 15 ambient temperatures are specified in the range of x/l ≤ 0.01 and r/r 0 ≤ 0.5, [21,22] where l is the length of the tube and r 0 is the radius of the tube. The external flow field is filled with air at the normal temperature and pressure.…”