This research proposes an algorithm for the simulation of time-periodic unsteady problems via the solution unsteady Euler and Navier-Stokes equations. This algorithm which is called Time Spectral method uses a Fourier representation in time and hence solve for the periodic state directly without resolving transients (which consume most of the resources in a time-accurate scheme). Mathematical t...

Unsteady-state (USS) core flood experiments provide data for deriving twophase relative permeability and capillary pressure functions. The experimental data is uncertain due to measurement errors, and the accuracy of the derived flow functions is limited by both data and modeling errors. History matching provides a reasonable means of deriving in-phase flow functions from uncertain unsteady-sta...

The fluid dynamic analysis of animal wakes is becoming increasingly popular in studies of animal swimming and flying, due in part to the development of quantitative flow visualization techniques such as digital particle imaging velocimetry (DPIV). In most studies, quasi-steady flow is assumed and the flow analysis is based on velocity and/or vorticity fields measured at a single time instant du...

This study is concerned with the unsteady motion of two solid spherical particles in an unbounded incompressible Newtonian flow. The background flow is uniform and can be time dependent. In addition, the particle Reynolds numbers 2aVa / and 2bVb / , based on characteristic particles velocities Va and Vb, are assumed to remain small throughout the motion. Here, a and b denote the particle radii ...

A combined computational fluid dynamics (CFD) and experimental study of interaction of main gas path and rim sealing flow is reported. The experiments were conducted on a two stage axial turbine and included pressure measurements for the cavity formed between the stage 2 rotor disc and the upstream diaphragm for two values of the diaphragm-to-rotor axial clearance. The pressure measurements ind...

Negative surges can be caused by a sudden change in flow resulting from a decrease in water depth. In the present study, some physical experiments were conducted in a rectangular channel to characterize the unsteady free-surface profile and longitudinal velocity beneath a negative surge propagating upstream. The physical observations showed that, during the first initial instants, the celerity ...

The shallow water equations are a mathematical tool widely applied for the simulation of flow routing in rivers and floodplains, as well as for flood inundation mapping. The interest of many researchers has been focused on the study of simplified forms of the original set of equations. One of the most commonly applied simplifications consists of neglecting the inertial terms. The effects of suc...

T. J. Trella, U.S. Department of Transportation, Transportation Systems Center, Cambridge, Massachusetts 02142 and A theoretical model was developed of the nonlinear dynamic response of a reciprocating air compressor discharge valve system considering unsteady flow. It constitutes an extension of previous modeling procedures where the flow was considered in a quasi steady manner. The most simpl...

Submitted for the DFD12 Meeting of The American Physical Society Lifetime Characterization of Electro-Luminescence Based Pressure-Sensitive Paint System for Unsteady Flow Field Measurements YOSHIMI IIJIMA, HIROTAKA SAKAUE, JAXA — Electro-luminescence based pressure-sensitive paint (EL-PSP) system uses an EL as an illumination source for a PSP measurement. EL can be directly applied onto a PSP m...

An unsteady sampling routine for a general parallel direct simulation Monte Carlo method called PDSC is introduced, allowing the simulation of time-dependent flow problems in the near continuum range. A post-processing procedure called DSMC rapid ensemble averaging method (DREAM) is developed to improve the statistical scatter in the results while minimising both memory and simulation time. Thi...