Skip to Main Content
 

Global Search Box

 
 
 
 

Files

ETD Abstract Container

Abstract Header

An MD-SPH Coupled Method for the Simulation of Reactive Energetic Materials

Abstract Details

2017, PhD, University of Cincinnati, Engineering and Applied Science: Aerospace Engineering.
Reactive energetic materials have long been the interest of researchers due to their significant applications in the military industry. Much research has been done on the subject at macroscopic scale in the past decades and research at microscopic scale has been initiated recently with the invention of molecular-scale simulation tool LAMMP with ReaxFF. The equation of state (EoS) is the relation between physical quantities (pressure, temperature, energy and volume) describing thermodynamic states of materials under a given set of conditions. It plays a significant role in determining the characteristics of energetic materials, such as Chapman-Jouguet (CJ) point and detonation velocity. Furthermore, EoS is the key to connect microscopic and macroscopic phenomenon when simulating the macroscopic effects of an explosion. For instance, ignition and growth model for high explosives uses two Jones-Wilkins-Lee (JWL) EoSs, one for solid explosive and the other for gaseous products. It would be much less expensive and hazardous to obtain the EoSs of energetic materials through computational method instead of field experiment. In this thesis, the EoSs of solid and gaseous products of ß-HMX are calculated using molecular dynamics (MD) simulation with ReaxFF-d3, which is a reactive force field calculated from quantum mechanics. The microscopic simulation results are compared with experiments, first-principles calculations, and then applied in smoothed particle hydrodynamics (SPH) method for the macroscopic simulation of high explosives. SPH is a meshless Lagrangian method which was first invented to study astrophysics problems. SPH is advantageous in tracking free interfaces and dealing with large deformation, therefore it has been extended to fluid dynamics and solid mechanics. Ignition and growth model, as the most popular numerical model for high explosives, has been integrated in commercial software such as ANSYS LS-DYNA. In the thesis, ignition and growth model is integrated in our in-house SPH codes to simulate the detonation of high explosives. Aluminized explosive is an enhanced metalized explosive, which usually contains high explosive such as HMX, and uses aluminum particles (5~10 µm in diameter) as additive. The combustion of aluminum particles is complicated chemical process that involves reactions between aluminum and air, aluminum and gaseous products of explosive. During the combustion it generates large amount of heat to enhance long-last burning effect. Though aluminized explosive has been applied in military industry for decades, the mechanism underneath the process is still not thoroughly understood. The numerical modeling of aluminized explosive poses great challenge to simulation community till today. In the thesis, an afterburning model is used to simulate the combustion of aluminum particles in aluminized explosive. In recent years, more advanced and innovative SPH methods are proposed and studied extensively, such as Godunov SPH, which integrates Riemann solver and eliminates the need for artificial viscosity in traditional SPH. In the thesis, a Godunov SPH method is described and validated using benchmark problem and other numerical examples. Afterwards, the Godunov SPH method is applied for the the simulation of high explosive. Lastly, a three-dimensional SPH model with JWL++ model is developed for non-ideal explosive Ammonium nitrate/fuel oil (ANFO). The influence of smoothing length on simulation is investigated. A three-dimensional cylinder test model is developed for ANFO to test the stability and accuracy of the proposed SPH method with JWL++ model.
Guirong Liu, Ph.D. (Committee Chair)
Shaaban Abdallah, Ph.D. (Committee Member)
Yijun Liu, Ph.D. (Committee Member)
Francesco Simonetti, Ph.D. (Committee Member)
165 p.

Recommended Citations

Citations

  • Wang, G. (2017). An MD-SPH Coupled Method for the Simulation of Reactive Energetic Materials [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491559185266293

    APA Style (7th edition)

  • Wang, Guangyu. An MD-SPH Coupled Method for the Simulation of Reactive Energetic Materials. 2017. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491559185266293.

    MLA Style (8th edition)

  • Wang, Guangyu. "An MD-SPH Coupled Method for the Simulation of Reactive Energetic Materials." Doctoral dissertation, University of Cincinnati, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491559185266293

    Chicago Manual of Style (17th edition)