Meso-scale heating predictions for weak impact of granular energetic solids

An explicit, two-dimensional, Lagrangian finite and discrete element technique is formulated and used to computationally characterize meso-scale fluctuations in thermomechanical fields induced by low pressure deformation waves propagating through particulate energetic solids. Emphasis is placed on characterizing the relative importance of plastic and friction work as meso-scale heating mechanisms which may cause bulk ignition of these materials and their dependence on piston speed (vp ~ 50-500 m/s). The numerical technique combines conservation principles with a plane strain, thermoelastic-viscoplastic constitutive theory to describe deformation within the material meso-structure. An energy consistent, penalty based, distributed potential force method, coupled to a penalty regularized Amontons Coulomb law, is used to enforce kinematic and thermal contact constraints between particles. The technique is shown to be convergent, and its spatial (~ 2.0) and temporal (~ 1.5) convergence rate is established. Predictions show that alhough plastic work far exceeds friction work, considerably higher local temperatures result from friction work. Most mass within the deformation wave (~ 99.9%) is heated to approximately 330, 400, and 500 K, for vp = 50, 250, and 500 m/s, respectively, due to plastic work, whereas only a small fraction of mass (~ .001%) is respectively heated to temperatures in excess of 600, 1100 and 1400 K due to friction work. In addition to low speed impact, and contrary to conventional belief, friction work is shown to also be an important heating mechanism at higher impact speeds. The variation in spatial partitioning of bulk energy within the deformation wave structure with particle morphology and material properties is demonstrated

Adjustments in teaching Petroleum Engineering field operations lab-an LSU experience

Educating and preparing engineers for the 21 Century requires adequate changes in the style we teach and demonstrate knowledge, concepts and their application under complex conditions. Energy industry is undergoing fundamental changes globally, which needs to be transferred into the classroom, in order to enable future engineers to be prepared for contemporary issues in all aspects of oil and gas industry, especially exploration and production. One of the areas to be addressed at the LSU Petroleum Engineering is how we teach laboratory classes in order to prepare our students to easily adopt new safety requirements implemented in industry. In addition to technical competency required for high safety standards, it is also critical to develop a certain kind of behavior that will ensure acts of responsible, ethical decision making and leadership in the work place. Copyright 2009. Society of Petroleum Engineers. s