[en] The steady motion of a perfectly conducting inviscid liquid past a thin symmetric airfoil of finite conductivity, with the ambient magnetic field being aligned with the free stream is considered. (auth)

[en] The problem of the steady flow of an isothermal, incompressible viscoplastic time-independent, Casson fluid between two disks approaching each other at constant relative velocity is considered. The flow occurs in the region where the shear stress exceeds the yield value. The shape and extent of the core has been determined. It is found that the plug flow region occurs symmetrically in the middle of the region between the disks. The thickness of the core increases from the periphery to the centre of the disks. The flow is confined to the region between the core and the disks. The applied load has been found to increase almost proportionally to the Casson number. (author)

No abstract available

[en] The examinations of jet passing over an obtuse external angle are carried out. Aim of this work is study of different methods for elimination of zone reverse flows and creation of steady flow along external surface of low angle. Comparative results of wake flow on average characteristics at flow passing over an obtuse external angle are cited

[en] Non-integrability of the streamline system of equations for a steady Stokes flow, which Bajer and Moffatt introduced by the name of stretch–twist–fold flow, is discussed by an algebraic method without assuming its closeness to an integrable system. In the author's previous paper, the non-existence of a real meromorphic first integral of the streamline system was proved on the basis of Ziglin's theory and the differential Galois theory, where a parameter was assumed not to belong to a set of exceptional values. In this paper, this assumption is proved to be removable by making further use of some results from the differential Galois theory. The road to this result is explained in the form of a recipe in order to make clear how the differential Galois theory is applied. (paper)

[en] In a recent paper, Petroni et al. claim that a necessary condition for the instability of the two-dimensional steady flows is a 'double cascade' of energy and enstrophy respectively to larger and to smaller scales of motion. It is shown here that the analytical reasoning employed by Petroni et al. is flawed and that their conclusions are incorrect. What is true is that in any scale interaction (whether an instability or not), neither energy nor enstrophy can be transferred in one spectral direction only, but this result is extremely well known

[en] Velocity measurement in pulsating flows is more difficult than that in steady flows. One problem follows from the necessity to synchronize the measuring instrument with the characteristic of the flow which is not required for steady-flow measurements. The second challenge is high frequency response of the measuring device which is required for high frequency pulsating flow measurements. Because of development of more advanced measurement devices, there has recently been a growing interest in pulsating velocity measurement and the number of papers in this field has increased significantly in recent years. In this review, the most frequently-used advanced techniques for velocity measurement in pulsating flows are surveyed. The characteristics of different pulsating flows as well as the advantages and limitations of the developed techniques are discussed. (topical review)

[en] The present work deals with numerical investigation of a new class of bluff-body flows created in a steady uniform flow by combining streamwise (in-line) and rotational oscillation of a circular cylinder. The governing equations based on stream function-vorticity formulation are solved numerically to determine the characteristics of the flow in the near-wake region. Results are presented for five set of the four dimensionless groups which characterize these flows, for which it is found that overall characteristics of the vortex shedding from the cylinder oscillating in the streamwise direction are altered significantly by the addition of rotational oscillation. (author)

[en] The problem of unsteady conducting viscous flow of n-immiscible and incompressible fluids, occupying equal heights between parallel plates under the influence of periodic pressure gradient superposed on the steady flow has been studied. Expressions for velocity distributions for n-fluids have been obtained. The velocity distributions have been shown graphically against nondimensional distance in the case of two fluids in particular. (auth.)

[en] In a previous study of the laminar flow over a four-bladed helicopter rotor, abnormal Cp distributions were observed on the upper surfaces of the blades. To address this problem, the aerodynamic performance of the same rotor is investigated using the k - ω SST turbulence model, as contained in the WIND code. The rotor is configured as a Chimera moving grid in a quasi-steady flow field. The rotor rotation schedule and the blade twisting are implemented as specified in the wind tunnel testing of a RoBin generic helicopter. More realistic Cp distributions on the blade surfaces are thus obtained. The aerodynamic load distributions in the radial direction of the rotor plane are generated by integrating the pressure on each blade surfaces along the blade chordwise direction. The analyses of these load distributions in the azmuthal direction provide a critical insight into the rotor model, which is based on the actuator-disc assumption. Also, some preliminary results for the flow past a full helicopter configuration, including the rotor and the RoBin fuselage, are presented. The current paper demonstrates the Chimera grid topologies and the Chimera grid generation technique for both blade and fuselage configuration. This would provide a powerful tool to simulate flow past an entire helicopter and to study the rotor-fuselage flow interaction. (author)