A DSD Acceleration Effect in the Front Propagation with Dual HE detonation Initiation*

Experiments show that when two HE materials placed adjacently, a fast-propagating detonation in one of the HE regions can sometimes initiate a detonation in the other HE. Direct numerical simulations support this phenomenon. Let A and B stand for the two HE materials. In a typical case, the driving detonation in HE A has a propagation speed faster than the CJ velocity in HE B, and the induced detonation in B is necessarily concave.

 

It is desired to employ a DSD (detonation-shock-dynamics) evolution equation to describe the motion of the concave detonation front. Previous efforts attempted using a (D, kappa) relation and the results failed to describe the initiation-zone where the wave front is straight and moves with the CJ velocity.

 

We have found that by using a (D, kappa, D dot), (i.e., front velocity, curvature, acceleration) relation calibrated for LX-17 with a meshless DSD tracker, an initiation zone naturally appears. Our front tracking result closely matches direct reactive flow simulations. We conclude that this is new evidence to support our previous claim that an acceleration effect in a DSD evolution equation is necessary to describe the motion of a converging detonation.