We examine the characteristics of helical flow in a concentric annulus with radii ratios of 0.52 and 0.9, whose outer cylinder is stationary and inner cylinder is rotating. Pressure losses and skin friction coefficients are measured for fully developed flows of water and a 0.4% aqueous solution of sodium carboxymethyl cellulose (CMC), when the inner cylinder rotates at the speed of 0~62.82 rad/...

Following recent works of several authors like Huilgol, Bhattacharya etd. and Javadpour et al., this paper is to contribute further to the literature of axial flow in a rotational coaxial rheometer. We consider axial flow of Herschel Bulkley mode1 between two concentric cylinders with the inner one rotating, while the outer cylinder is held stationary. An attempt has been made to direct the...

Laminar stagnation flow, axi-symmetrically yet obliquely impinging on a rotating circular cylinder, as well as its heat transfer is formulated as an exact solution of the Navier-Stokes equations. Rotational velocity of the cylinder is time-dependent while the surface transpiration is uniform and steady. The impinging stream is composed of a rotational axial flow superposed onto irrotational rad...

By theoretically analyzing dynamic behavior of the crankshaft, the rolling piston and the blade inrolling-piston rotary compressors, constraint forces and sliding speed at each pair of movable machine elements were obtained, and unbalanced inertia forces and compressor vibrations were evaluated. It was concluded that theoretical results have a goodagreement with experimental ones. Moreover, it ...

The onset of instability induced by impulsively started rotating cylinder was first investigated experimentally by Chen and Christensen [1]. The initial laminar flow evolves into a secondary flow pattern which consists of a series of Taylor-like vortices. In this transient boundary-layer system the critical time tc to mark the onset of secondary motion becomes an important question. This proble...

The stability of steady, inviscid vortex pairs in equilibrium with a circular cylinder are studied by discretizing equations derived from contour dynamics. These flows were found previously using different methods in Elcrat, Fornberg, Horn & Miller (2000). There are two families of vortices, one with a pair of counter-rotating vortices standing behind the cylinder, which may be thought of as de...

We analyze the e!ect of inertia forces on damping induced during large shearing deformations of an isotropic, incompressible and homogeneous viscoelastic layer constrained between two rigid circular cylinders. The layer is deformed by holding the inner solid cylinder "xed and rotating the outer one by applying to it a time-harmonic axisymmetric tangential velocity. It is assumed that the layer ...

Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450°F (232°C) to about 750°F (400°C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cyl...