Experimental Analysis of an Axial Inducer Influence of the Shape of the Blade Leading Edge on the Performances in Cavitating Regime

Bakir, Farid; Kouidri, S.; Noguera, Ricardo; Rey, Robert

doi:10.1115/1.1539872

Cited by 45 publications

(19 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Andersons "area ratio method" goes in that direction, [B.4 and B.11]. Instead of determining head and impeller outlet angle via slip coefficients, the design is based on the area ratio A v , which relates the cross section A 2q = a 2 × b 2 between the blades at the impeller outlet to the throat area of the collector A 3q = a 3 × b 3 . The following relationships apply:…”

Section: Calculation Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Design of the Hydraulic Components

Gülich¹

2014

Centrifugal Pumps

View full text Add to dashboard Cite

As per the state of the art, the hydraulic design of the various types of impellers, diffusers, volutes and inlet casing is based on empirical methods such as described in this chapter. The first design created that way is then subject to analysis and optimization by CFD. Even then the accuracy of performance prediction is not always satisfactory. This, because the 3D-flow through the pump depends on the complex shapes of the flow paths given by the inlet casing, impeller and collector. To compound the issue, the interaction of the main flow with the flow in the impeller side rooms can have an unexpectedly large influence on the Q-H-curve and efficiency (an example can be found in chap. 9.1). Always remember that it is the combination of all parameters and shapes of the hydraulic channels which determines the flow patterns -hence performance. In order to reduce the uncertainties of performance prediction, a systematic approach to hydraulic design is advocated. To this end, chapter 7.14 introduces a novel concept for a fully analytical description of the impeller geometry. Prior to starting the hydraulic design all requirements the pump has to fulfill and the boundary conditions imposed should be thoroughly reviewed and documented (see "hydraulic specification" in Chap. 17). Methods and Boundary Conditions Methods for the Development of Hydraulic ComponentsThis chapter deals with one-dimensional calculation procedures and design methods for impellers, volute casings, diffusers and inlet casings. For developing these components, the main dimensions and blade angles are calculated in a first step. Subsequently, the hydraulic contours are designed based on certain rules and methods. Many pump manufacturers employ computer programs for this work, and the drawings are generated on 2D-CAD systems. However, these methods are also increasingly replaced by 3D-CAD systems with which fully three-dimensional ge- Fig. 7.45. The complex hydraulic channels can be evaluated better with such models than with the conventional two-dimensional representations in various sections and views. Even more importantly, 3D-CAD systems provide the capability to directly manufacture the hydraulic components (or the casting patterns) by NC milling, stereo lithography or other fast-prototyping processes, [16]. The advantages of such processes are evident in terms of geometrical accuracy and lead times (not in the least also for model tests with milled or stereo-lithographed components). Since manual designs on the drawing board are rather the exception, the subsequent discussion of the design methods emphasizes the fundamental aspects of the design processes rather than a very detailed description of geometrical operations. The development of hydraulic components often comprises the following steps:1. Calculation of the main dimensions and blade angles by one-dimensional methods based on empirical correlations for slip factors and hydraulic efficiencies (based on databases and experience), Chap. 3. 2. Generating an initial design. 3. Optionally...

show abstract

Section: Calculation Modelsmentioning

confidence: 99%

“…• Cross section at diffuser inlet: z Le × a 3 × b 3 The main dimensions are then determined in the following way:…”

Section: Calculation Modelsmentioning

confidence: 99%

Design of the Hydraulic Components

Gülich¹

2014

Centrifugal Pumps

View full text Add to dashboard Cite

show abstract

“…Conversely, several studies have been conducted to investigate the effects of the inducer design on its unsteady behavior: it has been found, for example, that the shape of the hub [13], of the leading edge [14], (Bakir et al 2002), and even of the casing [15] have significant influence on cavitation instabilities. The effects of unequal spacing of the blades have been also investigated by numerical simulations [16].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Cavitation Instabilities in a Four Blade Inducer

2009

View full text Add to dashboard Cite

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. The cavitating behavior of a four-blade inducer tested in the LML laboratory large test facility is considered in the present paper. Experimental investigations based on unsteady pressure measurements and records from a six-component balance mounted on the inducer shaft are performed. Spectral analysis of the signals enables to detect several characteristic frequencies related to unbalanced two-phase flow patterns. The objective of the present paper is the understanding of the physical phenomena associated to these frequencies. Therefore, wavelet decomposition, flow visualizations, and direct analysis of the high-frequency force, moment, and pressure signals are applied. Results at nominal flow rate only are considered. Not only classical unbalanced cavitation patterns, but also unexpected flow organizations are discussed.

show abstract

“…This frequency is then a witness of cavity instabilities. Vibrations are an handicap for many industrial applications, as for inducers ( [6][7][8]). …”

Section: Introductionmentioning

confidence: 99%

Study of Passive Control Study of the Cavitation Instability on a Venturi Profile

Danlos¹,

Mehal²,

Sarraf³

et al. 2012

Proceedings of the 8th International Symposium on Cavitation

View full text Add to dashboard Cite

SUMMARYAs a source of vibrations, noise, erosion and structure damages, cavitation is a major handicap for many industrial flows used in different domains from propeller or pump studies, to the analysis of hydrodynamic flows around a profile. This work presents results of the effect of a passive control method, based on surface roughness, on a venturi profile in order to determine how to reduce or even suppress cloud cavitation developed on its suction side. Visualizations and velocity measurements permit to detect the influence of roughness on flow development. So as to have a better understanding of flow dynamics of sheet and cloud cavitation, robust mathematical methods of imaging post-processing have been used like Proper Orthogonal Decomposition.

show abstract

Experimental Analysis of an Axial Inducer Influence of the Shape of the Blade Leading Edge on the Performances in Cavitating Regime

Cited by 45 publications

References 5 publications

Design of the Hydraulic Components

Design of the Hydraulic Components

Analysis of Cavitation Instabilities in a Four Blade Inducer

Study of Passive Control Study of the Cavitation Instability on a Venturi Profile

Contact Info

Product

Resources

About