22nd Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter
Volume 67, Number 8
Monday–Friday, July 11–15, 2022;
Anaheim, California
Session L01: Model Calibrations and Methodologies
2:00 PM–3:30 PM,
Tuesday, July 12, 2022
Anaheim Marriott
Room: Platinum 5
Chair: Robert Dorgan, Air Force Research Laboratory
Abstract: L01.00005 : The calibration of the products equation of state for high explosives
3:00 PM–3:30 PM
Abstract
Presenter:
Carlos Chiquete
(Los Alamos Natl Lab)
Author:
Carlos Chiquete
(Los Alamos Natl Lab)
The most accurate determination of a detonating high explosive’s (HE) products equation of state (EOS) requires calibration to experiment, usually via simulations of cylinder expansion tests where isentropic expansion of the products drives the motion of metal confiners. Typically, simplified representations of the detonation structure are used to refine the relevant EOS parameters. These programmed burn (PB) calculations typically assume an instantaneous reaction which results in a computationally efficient limit where solid reactant material is immediately converted to product gas, a uniform end state of the reaction across the front and a constant normal detonation speed. Recently, we have made a series of calculational improvements via introduction of finite reaction zone effects on both energy delivery and propagation, while maintaining instantaneous reaction. For energy release, we have used a velocity-adjusted method which modifies the post-wave arrival end states at each HE cell, sensitizing the flow to the reduced shock strength due to wave curvature. However, we also have relaxed the basic assumption of instantaneous reaction in favor of the more realistic Pseudo-Reaction Zone (PRZ) energy release PB model. The latter approach features a finite reaction rate and importantly, a finite reaction zone length scale. This advanced PB methodology can then be applied to the calibration of any products EOS form and is independent of any base parameter adjustment strategy as in the velocity adjusted methodologies. This then supports the generation of paired PB and reactive burn models possessing equivalent energy release properties but very distinct wave propagation characteristics. In this study, we discuss the relative merits of each calibration methodology to determine the importance of the reaction zone in the EOS parameterization process and also present selected applications of the resulting detonation performance models.