The goal of this paper is to investigate jump conditions for unsteady small perturbations at impermeable interfaces, slip or bonded, plane or not, between fluids and structures in the presence of initial flow and prestress. Based on conservative equations obtained from a mixed Eulerian-Lagrangian description, interface conditions are first derived in an elegant and straightforward manner thanks...

We use a new method, the cross power spectrum between the linear density field and the halo number density field, to measure the Lagrangian bias for dark matter halos. The method has several important advantages over the conventional correlation function analysis. By applying this method to a set of high-resolution simulations of 256 particles, we have accurately determined the Lagrangian bias,...

The spatial dependence of Lagrangian displacement and velocity statistics is studied in the context of a data assimilating numerical model of the Gulf Mexico. In the active eddy region of the Western Gulf, a combination of Eulerian and Lagrangian measures are used to locate strongly hyperbolic regions of the flow. The statistics of the velocity field sampled by sets of drifters launched specifi...

Compositional models describe the simultaneous flow and transport processes of multiple components flowing in coexisting phases in porous media [1, 2]. Because each component can transfer between different phases, the mass of each phase or a component within a particular phase is no longer conserved. Instead, the total mass of each component among all the phases must be conserved, leading to st...

Problems involving a transition between dense and dilute dispersed phase regimes often require hybridization of Eulerian-Eulerian (EE) Eulerian-Lagrangian (EL) methods for accurate efficient computational modeling. A hybrid EE-EL formulation is developed in this work from first principles, which asymptotes to well-established EE EL limiting conditions. smooth dynamic criterion corresponding alg...

We develop a new methodology for the numerical modeling of nonlinear free surface waves, caused by an advancing free surface disturbance, based on combining Lagrangian and Eulerian, or pseudoLagrangian, methods for the time updating of free surface geometry and motion. We solve potential flow equations with a threedimensional (3D) higher-order Boundary Element Method (BEM; Grilli et al., 2000, ...

In numerical simulations of fluid flow, the choice of the computational mesh is crucial. Traditionally, there have been two viewpoints, utilizing the Lagrangian or the Eulerian framework, each with its own advantages and disadvantages. In a pioneering paper [1], Hirt et al. developed the formalism for a mesh whose motion could be determined as an independent degree of freedom, and showed that t...

offshore pipelines used for oil and gas transportation are often buried to avoid damage from fishing activities and to provide thermal insulation. thermal expansion and contraction of the pipeline during operation can lead to lateral or upheaval buckling. a safe buried pipeline design must take into account a reliable evaluation of soil uplift resistance and pipe embedment depth. while the cost...