Blast Wave Target Interacton Modeling (BWTITM)
Computational Fluid Dynamics Using BWTITM
BWTI™ (Blast Wave Target Interaction) is an “in-house” code developed by BakerRisk to simulate the generation and propagation of blast and shock waves and the interaction of such waves with structures. The code is capable of modeling blast waves resulting from vapor cloud explosions (VCE), pressure vessel bursting (PBV), and high explosive (HE) detonations. The main application areas for this code are engineering-level analyses involving scenarios where blast wave shielding and focusing are relevant, such that simplified methods which neglect these effects would not yield accurate results. BWTI™ is employed where the blast source is well qualified and the main focus of the evaluation is on the blast wave propagation and interaction (e.g., a bursting pressure vessel within an enclosure). Four BakerRisk technical staff members are involved in BWTI™ numerical analysis.
BWTI™ solves a set of integral equations governing an inviscid flow. The set of Eulerian governing equations is numerically calculated on an unstructured grid using an explicit, upwind, node-centered finite volume method with a second-order extension of Godunov’s scheme. The unstructured mesh formulation allows irregular geometries to be conveniently represented. An adaptive mesh can be employed. The adaptive mesh allows a refined grid to be employed in the vicinity of the blast wave while using a coarser grid away from the wave, thus ensuring an accurate simulation with reduced computational demands. BWTI™ has been validated against experiments for VCE, PVB, and HE explosion sources.
BakerRisk has employed BWTI™ to evaluate blast loads for a number of commercial projects, ranging from condensed phase explosions and bursting pressure vessels within enclosures to vapor cloud explosions in the exterior environment. BWTI™ is employed where simplified blast wave propagation and loading techniques are not applicable (e.g., where blast wave focusing or shielding are relevant). Examples of these types of projects include the following evaluations:
- VCE blast loads on chemical processing plant buildings considering the effects of shielding and focusing from surrounding structures
- HE and BPV blast loads within enclosures (bays, test fixtures, blast cells, etc.) and corresponding leakage loads in surrounding areas
- Evaluation of high pressure tools (down hole tools)
- Blast loads on building groups due to HE detonations
- External blast load due to VCE within a vented enclosure
- Effectiveness of door blast shield designs
- Mach reflections, reflection factors, and clearing effects for a VCE blast wave impacting a typical building
- Research and Development
BakerRisk has performed over one hundred projects worldwide using BWTI™.
BWTI™ Example of Blast Wave-Structure Interaction
BWTI™ Simulation of a VCE within a Vented Enclosure
BWTI™ Simulation of an HE Explosion within a Single Room
Failure of Blast Door Shielding
BWTI™ Simulation of Blast Door Shielding Failure
BWTI™ Simulation of Blast Focusing