Effect of blade wrap angle on efficiency and noise of small radial fan impellers—A computational and experimental study

Scheit, Christoph; Karic, B.; Becker, Stefan

doi:10.1016/j.jsv.2011.10.014

Cited by 29 publications

(12 citation statements)

References 19 publications

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“…The first code is the finite-element multiphysics solver CFS++ [14], which is based on Lighthill's analogy. The second one is called SPySI (sound prediction by surface integration), which is predicated on the porous Ffowcs Williams-Hawkings method [15]. Such tools for noise prediction can be very useful in wind turbine design in order to optimize the system with respect to noise and aerodynamic performance.…”

Section: State Of the Art Of Vawts And Purpose Of This Workmentioning

confidence: 99%

Aeroacoustics of Darrieus Wind Turbine

Weber¹,

Becker²,

Scheit³

et al. 2015

International Journal of Aeroacoustics

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The objective of this paper is to validate two different numerical methods for noise prediction of the H-Darrieus wind turbine using a complementary approach consisting of experimental measurements and numerical simulations. The acoustic measurements of a model scale rotor were performed in an anechoic wind tunnel. This data is the basis for the validation of the computational aeroacoustic simulations. Thereby, we have applied two different numerical schemes for noise prediction using hybrid methods. As usual in hybrid aeroacoustic approaches, flow field and acoustic calculations are carried out in separate software packages. For both schemes the time-dependent turbulent flow field is solved with Scale-Adaptive Simulation. The two schemes then differ in how the location of the acoustic sources and their propagation is calculated. In the first scheme the acoustic source terms are computed according to Lighthill's acoustic analogy which gives source terms located on the original CFD grid. These source terms are projected onto a coarser acoustic grid on which Lighthill's inhomogenous wave equation is solved by the Finite Element (FE) method. The second scheme uses the Ffowcs WilliamsHawkings (FW-H) method which is based on a free field Green's function. The scheme uses a porous integration surface and implements an advanced time formulation. Both methodologies are compared with experimental data.

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Section: State Of the Art Of Vawts And Purpose Of This Workmentioning

confidence: 99%

Aeroacoustics of Darrieus Wind Turbine

Weber¹,

Becker²,

Scheit³

et al. 2015

International Journal of Aeroacoustics

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“…Impellers offer very high compression ratios and are usually more efficient than axial compressors but shall generate undesired noise [1]. In this regard, a majority of the existing archived publications explores possible ways to reduce the noise generated by impellers [2,3]. The main interest of the present work lies in the proper characterization of critical rotational velocities where amplitudes of motion of the bladed impeller may reach undesired high levels induced by a unilateral-contact driven mechanism leading to vibratory reso-nances.…”

Section: Introductionmentioning

confidence: 99%

Unilateral contact induced blade/casing vibratory interactions in impellers: Analysis for rigid casings

Batailly

Meingast

Legrand

2015

Journal of Sound and Vibration

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This contribution addresses the vibratory analysis of unilateral-contact induced structural interactions between a bladed impeller and its surrounding rigid casing. Such assemblies can be found in helicopter or small aircraft engines for instance and the interactions of interest shall arise due to the always tighter operating clearances between the rotating and stationary components. The investigation is conducted by extending to cyclically symmetric structures an in-house time-marching based tool dedicated to unilateral contact occurrences in turbomachines. The main components of the considered impeller together with the associated assumptions and modeling principles considered in this work are detailed. Typical dynamical features of cyclically symmetric structures, such as the aliasing effect and frequency clustering are explored in this nonlinear framework by means of thorough frequency-domain analyses and harmonic trackings of the numerically predicted impeller displacements. Additional contact maps highlight the existence of critical rotational velocities at which displacements potentially reach high amplitudes due to the synchronization of the bladed assembly vibratory pattern with the shape of the rigid casing. The proposed numerical investigations are also compared to a simpler and (almost) empirical criterion: it is suggested, based on nonlinear numerical simulations with a linear reduced order model of the impeller and a rigid casing, that this criterion may miss important critical velocities emanating from the unfavorable combination of aliasing and contact-induced higher harmonics in the vibratory response of the impeller. Overall, this work suggests a way to enhance guidelines to improve the design of impellers in the context of nonlinear and nonsmooth dynamics.

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“…Some of them are impeller exit angles [4][5][6][7], blade wrap angle [8,9], blade thickness [10] and impeller exit width [11]. Anagnostopoulos [12] investigated the effect of blade geometry on pump efficiency using his 2-D turbulent flow solver.…”

Section: Introductionmentioning

confidence: 99%

Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

Babayigit

Kocaaslan

Aksoy

et al. 2015

EPJ Web of Conferences

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Abstract. Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m

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Effect of blade wrap angle on efficiency and noise of small radial fan impellers—A computational and experimental study

Cited by 29 publications

References 19 publications

Aeroacoustics of Darrieus Wind Turbine

Aeroacoustics of Darrieus Wind Turbine

Unilateral contact induced blade/casing vibratory interactions in impellers: Analysis for rigid casings

Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

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