The linear flow analysis of turbomachinery aeroelasticity views the unsteady flow as the sum of a background nonlinear flow field and a linear harmonic perturbation. The background state is usually determined by solving the nonlinear steady flow equations. The flow solution representing the amplitude and phase of the unsteady perturbation is instead given by the solution of a large complex line...

A sequential implicit numerical scheme is proposed for a system of partial differential equations defining the transport of heat and mass in the channel flow of a variable-viscosity fluid. By adopting the backward difference scheme for time derivative and the central difference scheme for the spatial derivatives, an implicit finite difference scheme is formulated. The variable-coefficient diffu...

The Parareal algorithm is used to solve time-dependent problems considering multiple solvers that may work in parallel. The key feature is a initial rough approximation of the solution that is iteratively refined by the parallel solvers. We report a derivation of the Parareal method that uses a convergence acceleration technique to improve the accuracy of the solution. Our approach uses firstly...

Flow in the first two-stage of V 94.2 gas turbine is simulated numerically. In this turbine, the second stator is clocked relative to the first stator to different positions. Steady-state analysis was carried out by varying the circumferential relative position of the consecutive stator vanes to study the effects of the clocking on turbine performance. A density based compressible inviscid ...

An adaptive mesh projection method for the time-dependent incompressible Euler equations is presented. The domain is spatially discretised using quad/octrees and a multilevel Poisson solver is used to obtain the pressure. Complex solid boundaries are represented using a volume-of-fluid approach. Second-order convergence in space and time is demonstrated on regular, statically and dynamically re...

In this paper we derive a posteriori error estimates for the compositional model of multiphase Darcy flow in porous media, consisting of a system of strongly coupled nonlinear unsteady partial differential and algebraic equations. We show how to control the dual norm of the residual augmented by a nonconformity evaluation term by fully computable estimators. We then decompose the estimators int...

Directional wave energy focusing in space is one of the mechanisms that may contribute to the generation of a rogue wave in the ocean. To this effect, in this paper, we study the generation of extreme waves in a three-dimensional numerical wave tank from the motion of a snake wavemaker. The numerical model solves incompressible fully nonlinear free-surface Euler equations for potential flow, us...

This study investigates the behavior of blast wave by employing the finite volume method to solve the associated three-dimensional, time-dependent, inviscous flow Euler equations. The numerical results are shown to be in good agreement with the experimental results obtained from shock tube flow studies. The results also identify the complex phenomena of flow structures, pressure distributions, ...

The study of strongly out-of-equilibrium states and their time evolution towards thermalization is critical to the understanding an ever widening range physical processes. We present a numerical method that for first allows solution most difficult part time-dependent Boltzmann equation: full scattering term. Any number bands (and quasiparticles) with arbitrary dispersion, any high order channel...

Low speed gas flows are studied using a Unified Flow Solver (UFS) that automatically selects continuum-fluiddynamic and kinetic solvers for near-equilibrium and kinetic domains. Direct Numerical Solution of the Boltzmann equation is used in the kinetic domains at moderate and high local Knudsen number, while kinetic schemes for Euler or Navier Stokes equations are used in the continuum domains....