Despite of a lot of efforts and interesting results, accretion disk theory is still under development and there are several unknowns: specifically, all available models are in the steady state approximation. In this letter, we investigate unsteady motion, beginning with shock wave–turbulence interaction. Indeed, unsteady flow allows this type of interaction, which in turn results in substantial...

We present a new algorithm for combining a fully anisotropic goal-oriented mesh adaptation with the transient fixed point method for unsteady problems. The minimization of the error on a functional provides both the density and the anisotropy (stretching) of the optimal mesh. This method is used for specifying the mesh for a time subinterval from the state and the adjoint. The global transient ...

The influence of enforced periodic concentration variations on a continuous stirred tank reactor was studied theoretically. The unsteady-state-processing becomes advantageous under certain conditions. This can be shown for an irreversible consecutive-competing reaction. The yield and selectivitv of the intermediate oroduct can exceed the values obtainable at steady-state-processing in the menti...

In this study the thermal conductivity and the volumetric heat capacity of non-Newtonian fluids are investigated. These fluids find many applications in chemical, medical and food industries. They mostly have viscoelastic behavior and generally differ from Newtonian fluids. Two non-Newtonian fluids, solutions of xanthan and carboxy methyl cellulose in water with various concentrations have bee...

AD-P004 168 AD-P004 169 TITLE: Superroaneuverability. Wing Rock Flov Phenomena. Potential Applications of Forced Unsteady Flows. Unsteady Stall Penetration of an Oscillating Swept Wing. Simultaneous Flow Visualization and Unsteady Lift Measurement on an Oscillating Lifting Surface. A Visual Study of a Delta Wing in Steady and Unsteady Motion. Comparative Visualization of Accelerating Flow aroun...

New analytic solutions for unsteady magnetohydrodynamic (MHD) flows of a generalized second-grade fluid have been derived. The generalized second-grade fluid saturates the porous space. Fractional derivative is used in the governing equation. The analytical expressions for velocity and shear stress fields have been obtained by using Laplace transform technique for the fractional calculus. The o...

The determination of the optimal distribution of the catalytic activity profile, whichmaximizes the catalytic effectiveness, in created unsteady state conditions, is analyzed andtreated numerically for the case of a simple reaction. It was proven that the modulation, of thetemperature and the reactant concentration of the external bulk fluid, leads to a considerableincrease of the catalytic eff...

The pressure- and temperature-sensitive paint (PSP/TSP) technique, for steady-state and unsteady-state measurements, is becoming widespread. However, unsteady quantitative measurement is still difficult because non-uniform distribution of the probes over a test model may cause errors in the results. We focus on the dipping method that applies two luminophores into a binding material to improve ...

This paper demonstrates efficient solver technologies applied to the non-linear frequency domain (NLFD) method. The basis of the NLFD method is to assume the time period of the solution s oscillation and to transform both the solution and residual using a discrete Fourier transform. An unsteady residual is formed in the frequency domain and iteratively driven to a negligible value. This method ...

Potential flow solvers for 3D aerodynamic flows are commonly used in industrial applications. Two main difficulties preventing the even more widespread use of these codes are the limitations on the number of discretization elements and the user expertise and effort required to specify the wake location. In the paper we present an automatic wake generation strategy for a potential flow solver, a...