Performance and flow condition of small-sized axial fan and adoption of contra-rotating rotors

Shigemitsu, Toru; Fukutomi, Junichiro; Okabe, Yuki

doi:10.1007/s11630-010-0001-0

Cited by 35 publications

(21 citation statements)

References 5 publications

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“…The first counter-rotating machines have appeared in aeronautic and marine applications, in open configuration. Nowadays, these machines with two coaxial axial-flow fans that rotate in opposite direction see a revival of interest in several distinct configurations -open and ducted flows, shrouded or not shrouded rotors-in various subsonic regime applications [7][8][9] . The previous studies concluded that the presence of the rear rotor improves the global efficiency 3,4 and also increases the operating flow-rate range.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of the Instationary Flow Between Two Ducted Counter-Rotating Rotors

Nouri¹,

Danlos²,

Ravelet³

et al. 2013

Journal of Engineering for Gas Turbines and Power

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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. An experimental study on counter-rotating axial-flow fans was carried out. The fans of diameter D = 375 mm were designed to match the specification point using an original method. The counter-rotating fans operate in a ducted-flow configuration and the overall performances are measured in a normalized test bench. The rotation rate of each fan is independently controlled and the axial spacing between rotors can be varied from S = 10 to S = 180 mm. Systematic measurements of the global performances and local measurements of the velocity field and of the wall pressure fluctuations are performed, in order to first validate the design method, and to explore the effects of the two specific free parameters of the system: the axial spacing and the ratio of rotation rates. The results show that the efficiency is strongly increased compared to a conventional rotor or to a rotor-stator stage. The developped design method slightly over-predicts the pressure rise and slightly under-predicts the best rotation ratio. The system is moreover highly efficient on a wide range of flow-rates and pressure rises: this system has thus a very flexible use, with a large patch of high efficient operating points in the parameter space.Atmospheric

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Section: Introductionmentioning

confidence: 99%

Experimental Study of the Instationary Flow Between Two Ducted Counter-Rotating Rotors

Nouri¹,

Danlos²,

Ravelet³

et al. 2013

Journal of Engineering for Gas Turbines and Power

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“…The counter-rotating impellers driven separately by the isolated motors have been presented by Prof. Shigemitsu et al [6] [7], but the proposed impellers quite differ from them as the impellers are driven, in the smart control, by the peculiar motor with the double rotational armatures. This paper investigates experimentally the effects of the impeller profiles not only the pump performances but also on the rotational speeds of the front and the rear impellers against the discharge, using the four kinds of the impellers whose loads are low and/or high at the normal discharge.…”

Section: Front Impellermentioning

confidence: 99%

Counter-Rotating Type Pumping Unit (Impeller Speeds in Smart Control)

Kanemoto¹,

Komaki²,

Katayama³

et al. 2011

International Journal of Fluid Machinery and Systems

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Turbo-pumps have weak points, such as the pumping operation is unstable on the positive slope of the head curve and/or the cavitation occurs at the low suction head. To improve simultaneously both weak points, the first author invented the unique pumping unit composed of the tandem impellers and the peculiar motor with the double rotational armatures. The front and the rear impellers are driven by the inner and the outer armatures of the motor, respectively. Both impeller speeds are automatically and smartly adjusted in response to the pumping discharge, while the rotational torques between both impellers/armatures are counter-balanced. Such speeds contribute to suppress successfully not only the unstable operation at the low discharge but also the cavitation at the high discharge, as verified with the axial flow type pumping unit in the previous paper.Continuously, this paper investigates experimentally the effects of the tandem impeller profiles on the pump performances and the rotational speeds against the discharge, using the impellers whose loads are low and/or high at the normal discharge. The worthy remarks are that (a) the unstable operation is suppressed as expected and the shut off power is scarcely large in the smart control, (b) the blade profile contributes to determine the discharge giving the maximum/minimum rotational speed where the reverse flow may incipiently appears at the front impeller inlet, (c) the tandem impeller profiles scarcely affect the rotational speeds, while the loads of the front and the rear impellers are same, but (d) the impeller with the low load must run faster and the impeller with the high load must run slower at the same discharge to take the same rotational torque, and (e) the reverse flow at the inlet and the swirling velocity component at the outlet of the front impeller with the high load require making the rotational speed of the rear impeller with low load fairly faster at the lower discharge.

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“…Le développement de machines à forte vitesse spécifique et de taille réduite en régime subsonique suscite actuellement une forte demande dans de nombreux domaines industriels [Shigemitsu et al, 2007;Shigemitsu et al, 2010;Pin et al, 2011]. Des machines conventionnelles amènent un rendement bas et génèrent un bruit aérodynamique relativement élevé: problème crucial pour des raisons de confort de l'utilisateur (ventilateurs d'ordinateurs) ou de discrétion acoustique (circulateurs de sous-marins).…”

Section: Introductionunclassified

Étude expérimentale de l'écoulement et de l'interaction entre deux rotors contrarotatifs subsoniques

2014

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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.This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8509 To cite this version :Hussain NOURI, Florent RAVELET, Farid BAKIR -Étude expérimentale de l'écoulement et de l'interaction entre deux rotors contrarotatifs subsoniques -La Houille Blanche -Vol. 2014, n°3, p.13-26 -2014 Any correspondence concerning this service should be sent to the repository Administrator : archiveouverte@ensam.eu ÉTUDE EXPERIMENTALE DE L'ECOULEMENT ET DE L'INTERACTION ENTRE DEUX ROTORS CONTRAROTATIFS SUBSONIQUES EXPERIMENTAL STUDY OF THE FLOW AND THE INTERACTION IN-BETWEEN TWO COUNTER-ROTATING SUBSONIC AXIAL-FLOW FANSRecently, the need for smaller axial fans with high specific speeds leads to the design of counter-rotating axial fans. The design of this kind of machines, which have promising aerodynamic performances, suffers from a lack of knowledge about their aerodynamics. Counter-rotating rotors, widely studied in aeronautics, are an effective alternative to conventional machines and offer many advantages: rotation ratio and diameter reduction, and high flexibility in use. However, a better understanding of their working and of the rotors interaction is required to enhance their design and to make them widely integrated in current applications. This experimental research work investigates on a ducted counter-rotating stage designed with a home code, MFT based on an inverse design method for rotors and rotor-stator stages, and to which a rapid and simple method is implemented to design the rear rotor. The study focuses on the effects of the rotation ratio and on the axial spacing between rotors. It highlights several aspects of the rotors interaction through global performance and local unsteady measurements.

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Performance and flow condition of small-sized axial fan and adoption of contra-rotating rotors

Cited by 35 publications

References 5 publications

Experimental Study of the Instationary Flow Between Two Ducted Counter-Rotating Rotors

Experimental Study of the Instationary Flow Between Two Ducted Counter-Rotating Rotors

Counter-Rotating Type Pumping Unit (Impeller Speeds in Smart Control)

Étude expérimentale de l'écoulement et de l'interaction entre deux rotors contrarotatifs subsoniques

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