Spiral flow theory

A publication by B. Colleman, H. Markwitz and W. Noll27 describes in detail the theory of viscosimetric flows which was further used by a number of investigators (see, for example, 23,24,28-29) to analyze axial flow in a clearance between motionless and rotating cylinders. The authors of 27,30) have demonstrated theoretically that the spiral flow can be considered as a mutual overlapping (superimposing) of two strains occurring in a simple shear (see Sect. 1.2). 

The theory of viscosimetric flows, as mentioned above, permits the consideration of a spiral flow (Fig. 1) as a superimposition of two simple-shear strains. This approach... 

The laminar flow data of Figure 3.39 have a higher slope (0.52 than predicted by theory (0.33)-probably because of "secondary flow effects". The data were taken in a spiral flow thin channel device. Whenever fluid passes through a curved tube or channel, centrifugal forces tend to throw fluid outward from the center of the channel. It then recirculates inward along the walls of the channel (see Figure 3.40). It is well known that coiled tube heat exchangers possesses superior heat transfer characteristics because of secondary flow effects. 

On the Theory of Spiral (Helicyl) Flow of Molten Thermoplastic... 

Important parameters in cyclone operation can be established by considering simple cyclone theory. Figure 8.1 shows a sketch of a typical cyclone. Air at a flow of Q cm3/s enters tangentially, revolving NT times in the cyclone before it is discharged. Dust that is removed from the air spirals down into the dust discharge port. 

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