Numerical simulations of turbulent thermal, bubble and hybrid plumes

Information Theoretic Source Seeking Strategies for Multiagent Plume Tracking in Turbulent Fields

“…Similar to [16] and [17], we employ a particle filter representation of the posterior belief distribution to make the strategy computationally tractable for large complex spaces and distributable for mobile sensing teams. Our preliminary results demonstrate the viability of the strategy for single and multiple robots in simulation [15] where the plume is a three dimensional (3D) time-varying computational fluid model of the 2010 Deep Water Horizon oil spill [18,19]. Similar to works in the second category, we leverage the spatial distribution of a team of coordinated mobile sensors to more efficiently locate the source.…”

“…First, we present simulation results for a multi-robot team executing the described information theoretic search strategy in a realistic 2D turbulent field. Specifically, the team is tasked to localize the source of a leak using a computational fluid model of the 2010 Deep Water Horizon Oil Spill whose details are presented in [19]. The plume is generated by an inlet buoyancy flux B i = gw i A i α b,i = 5 × 10 −6 m 4 · s −3 where g = 9.8 m · s −2 is the gravity acceleration magnitude, w i = 4 cm · s −1 is the inlet liquid velocity, A i = πr 2 i = 0.005 m 2 is the source cross-section area of radius r i and α b,i = 0.026 is the inlet gas volume fraction.…”

“…The work in [18] builds upon this result to develop a computationally tractable search strategy suitable for large complex spaces and distributable for mobile sensing teams through the use of particle filters. Additionally, the extensions described in [18] were validated using a realistic 3D time-varying computational fluid model of the 2010 Deep Water Horizon oil spill [19]. In this work, we consolidate and build upon [15,18] to develop coordinated search strategies for mobile sensing teams to effectively find and localize the source of a dispersed contaminant in turbulent media.…”

How Do Oil, Gas, and Water Interact Near a Subsea Blowout?

“…Recently, large eddy simulation (LES) has been applied to complex oil and gas plumes in stably stratified conditions (Fabregat et al, 2015, and recent work of Alexandre Fabregat, City University of New York, and colleagues; Fraga et al, 2016;Yang et al, 2016). LES models do not rely on self-similarity and are able to directly resolve large-and intermediate-scale turbulent motions, relying on closure models for the effects of subgrid-scale (SGS) features.…”

“…Using an Eulerian framework, the incompressible NavierStokes equations are solved for the water velocity field, and a convection-diffusion equation solves for the water density field, which is coupled to the buoyancy term in the Navier-Stokes equations using the Boussinesq approximation (Fabregat et al, 2015;Yang et al, 2016). Both flow and density equations are filtered at the LES grid scale, and several different SGS models have been used to close the equations.…”