The Vortex Drop.

Ackers, Peter; Crump, E S

doi:10.1680/iicep.1960.11720

Cited by 19 publications

(5 citation statements)

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“…(6) (as Knapp [5] and Pica [7] do), while the measurements of Binnie and Hookings [2] return positive values, thus justifying eqn. (7) (as Ackers and Crump [4] do). In order to account for this difference, it can be assumed that Viparelli's section 0-0 does not match that of Binnie and Hookings.…”

Section: Pressure Distribution Analysismentioning

confidence: 94%

“…Its inventor Drioli [1], and increasing numbers of authors thereafter (i.e. [2][3][4][5][6][7][8][9]) have investigated the vortex inlet with seemingly different procedures that can, however, be traced back to a single template. Nevertheless, the definition of the actual velocity distribution in the inlet chamber and the pressure distribution along the radius r in the first cross section of the shaft remain controversial issues.…”

Section: Introductionmentioning

confidence: 99%

“…(6) to be valid, theoretically justifying this position with the hypothesis of a balancing of the outward centrifugal forces (caused by the curvature of the trajectories in the horizontal plane 0-0, reported in fig.1) with the inward centrifugal forces (caused by the curvature of the trajectories in vertical planes). Binnie and Hookings [2], Ackers and Crump [4] and Adami [6], on the other hand, believe that only the curvature in the horizontal plane should be taken into account and, therefore, although different schemes are considered, they hypothesize a pressure distribution reported in eqn. (7).…”

Section: Introductionmentioning

confidence: 99%

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Experimental measurements for the control of a vortex shaft theoretical model

Ciaravino¹,

Ciaravino²,

Doria³

2007

WIT Transactions on Modelling and Simulation, Vol 46

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With reference to the hydrodynamic working of a dropshaft fitted with a vortex inlet, there are still two problems that are open to debate: the actual distribution of velocities at the inlet and the pressure distribution along the radius in the first cross section of the shaft. The majority of researchers assume that the velocity distribution is both irrotational and axially symmetrical, although some forty years ago Viparelli experimentally showed that such an assumption is actually incorrect, hypothesizing that the flow is symmetrical but not irrotational. Moreover, the determination of pressure distribution in the different proposed theories remains a debatable issue, with some claiming that the distribution of pressure is equal to zero while others maintain it is positive. In the present paper, two series of experimental measurements concerning the above-mentioned problems are analyzed. A first series of experimental tests performed with a Laser Doppler Anemometer confirms a different velocity distribution hypothesis: irrotational but not entirely symmetrical. A second series of experimental tests deals with pressure measurements made in the vertical shaft inlet. Contrary to what has been hypothesized by other researchers, these measurements indicate negative pressure values.

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Section: Pressure Distribution Analysismentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental measurements for the control of a vortex shaft theoretical model

Ciaravino¹,

Ciaravino²,

Doria³

2007

WIT Transactions on Modelling and Simulation, Vol 46

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“…g m = g p . Equation (1) leads to the well-known velocity scale ratio V r , discharge scale ratio Q r , time scale ratio t r and roughness coefficient scale ratio k r (expressing the roughness parameter χ r using the…”

Section: Hydraulic Modelsmentioning

confidence: 99%

Simulation and Modelling with Digital Image Processing: Hydraulic Models

Leopardi

2012

2012 Symposium on Photonics and Optoelectronics

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A physical model is used to describe one or more fieldsize phenomena and, in representing them, it generates other quantities, which are the final output of the system. Sometimes the required thorough measurement of such quantities can lead to lose the total perception of the phenomenon under investigation. Digital image processing can not and should not obviously replace the measurements, but it can be a useful tool for capturing the global behaviour of the model-system and consequently of reality. This process can be especially effective in cases where, for certain configurations or for simplifying the model to its essential characteristics, the aim is to seek a simple representation, although not completely corresponding to reality. Keywords-component: Image acquisition and analysis I. HYDRAULIC MODELSIn hydraulic models that are a scaled representation of hydraulic structure prototypes, gravity effects are usually predominant over surface tension effects and therefore Froude similitude is adopted.That is, the Froude number is the same for the model and the prototype, i.e.: p r m r F F = ⇒ p p 2 p m m 2 m L g V L g V =where the subscripts m and p refer to model and prototype parameters respectively. Based on the consideration that both the processes take place in the gravitational field, i.e. g m = g p . Equation (1) leads to the well-known velocity scale ratio V r , discharge scale ratio Q r , time scale ratio t r and roughness coefficient scale ratio k r (expressing the roughness parameter χ r using thewhere L r is the scale ratio. These relationships are the means which allow transferring the results measured in the model to the prototype scale for the phenomenon under investigation.The main difficult in constructing a physical model able to reproduce the full 3D prototype is to correctly scale the internal surface roughness. Equation (3) makes it possible to define the model roughness, once a roughness of the prototype and a scale parameter are assumed, Fig.1 . Figure 1Models are built according to design drawings and any subsequent updates, using commonly available materials. Limitations exist on the choice of the scale ratios, depending on the material type used for the model, as for small scale ratios (large models) it isn't possible to have fairly smooth surfaces for an adequate similitude, even with materials commonly used in laboratory, as PVC and PERSPEX.[6] [8] Each material has advantages that recommend its use for a particular purpose and disadvantages that prevent its universal use; in any case, all of them can be made smooth and waterresistant by appropriate treatments.

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“…Owing to the novelty of such an approach to siphoning, as far as the authors are aware, there are no studies available conceiving a reliable design for the system, apart from some work on vortex chambers carried out by [1][2][3][4] and [5] in the context of drop shafts for energy dissipation in sewers and hydropower plants. Furthermore, the previous studies were carried out for constant atmospheric pressure conditions, wherein the proposed vortex flow conditions within the sealed box are subject to variable negative pressure conditions.…”

Section: Introductionmentioning

confidence: 99%