A numerical method for analysis of global instability-linear instability of entire flow fields-for incompressible viscous fluids was described. A flow past a circular cylinder at low Reynolds number was analysed and some stability characteristics such as eigenvalues, eigenfunctions and the critical Reynolds number were determined. The computed eigenmode that becomes unstable global mode above the critical Reynolds number was analysed and the mechanism of self-sustained oscillation was investigated from a view point of kinetic energy.

View full abstract

A flow induced by blade coating is studied using finite difference method. A new model which takes a free-surface flow downstream and a finite gap between the blade and the coated surface into account is presented here. We restrict our attention to steady, two-dimensional Stokes flow of an incompressible Newtonian liquid. The flow upstream is represented by Taylor-Hamel solution and the flow downstream by Coyne-Elrod solution.
Numerical solution shows more actual pressure distribution than Taylor-Hamel one and the shear stress on the coated surface.

View full abstract

This paper presents an overview of numerical flow analyses of arbitrarily designed multi-element airfoils. Compressible unsteady inviscid flows around airfoils are analyzed by integrating time-dependent Euler equations using finite difference techniques. Numerical solutions are obtained through an explicit upwind scheme in a boundary modified square grid of Cartesian coordinates.
Numerical calculations were performed on two-dimensional applications for a low-speed flow around an airfoil with variations in flap and spoiler in a wind tunnel. The pressure distributions and lift coefficients were compared with experimental data.

View full abstract