WO2022201103A1 - Ventilateur axial à bords d'attaque de pale dentelés - Google Patents

Ventilateur axial à bords d'attaque de pale dentelés Download PDF

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Publication number
WO2022201103A1
WO2022201103A1 PCT/IB2022/052728 IB2022052728W WO2022201103A1 WO 2022201103 A1 WO2022201103 A1 WO 2022201103A1 IB 2022052728 W IB2022052728 W IB 2022052728W WO 2022201103 A1 WO2022201103 A1 WO 2022201103A1
Authority
WO
WIPO (PCT)
Prior art keywords
fan
rotor
blades
blade
frame
Prior art date
Application number
PCT/IB2022/052728
Other languages
English (en)
Inventor
Piotr PIETRAS
Original Assignee
Cooling_Pl Zdziech Spolka Jawna
Synergy Cooling Piotr Pietras
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cooling_Pl Zdziech Spolka Jawna, Synergy Cooling Piotr Pietras filed Critical Cooling_Pl Zdziech Spolka Jawna
Priority to EP22723182.6A priority Critical patent/EP4314569A1/fr
Publication of WO2022201103A1 publication Critical patent/WO2022201103A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
    • F04D29/38—Blades
    • F04D29/384—Blades characterised by form
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
    • F04D25/0613—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump the electric motor being of the inside-out type, i.e. the rotor is arranged radially outside a central stator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
    • F04D29/38—Blades
    • F04D29/384—Blades characterised by form
    • F04D29/386—Skewed blades
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05D2240/303—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the leading edge of a rotor blade

Definitions

  • the subj ect-matter of the invention is a low-speed axial fan suitable for mounting in a horizontal or vertical position, in particular in computer enclosures, CPU air coolers, CPU liquid coolers and other computer components, like computer PSUs.
  • blower fan is known from the European application description EP3343045 Al, in which a part of the ridge of each blade is equipped with symmetrical serrations.
  • European Application Description EP3591238 Al relates to an engine cooling system comprising an axial fan including a hub having an axis of rotation; a plurality of blades extending radially from the hub; and a fan cowl.
  • each blade has a front edge and a rear edge, and wherein each blade has at least one flow element to reduce the airflow turbulence, selected from the group consisting of: a plurality of ridges positioned at the front edge, a plurality of serts positioned at the rear edge, and ribs extending transversely across each blade.
  • the fan cowl includes a guard with a wire extending between the first and second opening. Whereby the guard has a tapering section configured to restrict the flow of air moving from the first opening to the second opening.
  • European Application Description EP3034886 Al discloses a blade for a fan rotor having an end region facing the hub, a first blade side and a second blade side, wherein the blade has at least one rib in the end region facing the hub.
  • the rib has an outer contour that simulates a flow profile and at least one rib having, at the rib start point, a rib base in the end region facing the hub and a rib base at the opposite rib end point, the rib base being positioned higher in the axial direction than the rib base at the rib end point;
  • the rib has an end geometry in the area of the outer contour, the end geometry forms a sawtooth profile, the end geometry of the rib forms an alpha angle between -45° and + 45° to the tangent to the contour of the surface of the other side of the blade, characterized in that: on the approach to the hub, the rib has a beta angle to the radial direction, with the beta angle ranging between -80° and + 80°.
  • the purpose of the invention was to provide a new structure of a low-speed axial fan with improved acoustic properties.
  • the essential feature of the invention is a low-speed axial fan suitable for mounting in a horizontal or vertical position, in particular in computer enclosures, comprising a frame, a motor and a plurality of blades extending from the rotor towards the frame, the frame comprising a support part and slats connected to the support part and fixing the motor and the plurality of fan blades mounted on the motor rotor, characterised in that each of the multiple blades has a uniformly finished edge of the ridge and a substantially serrated leading edge provided with serts, the spacing between the serts being 1/10 to 1/5 of the length of the serrated leading edge of the blade and the rotor being fitted with a fluid dynamic bearing (FDB).
  • FDB fluid dynamic bearing
  • the spacing between the serts is 1/7 of the length of the serrated leading edge of the blade.
  • the solution ensures the elimination of prominent tonal sounds in the bands of about 315 Hz and about 3150 HZ;
  • the serrated shaping of the leading edge of the fan blades according to the invention can be produced by means generally known in the state of the art without increasing the cost of production.
  • fig. 1 shows a fan according to the invention in front view
  • fig. 2 shows the fan according to the invention in a frameless view
  • fig. 3 shows the tonal noise intensity of known low-speed axial fans
  • fig. 4 shows a diagram of the fans compared in example 4, where A) shows the test fan and B) shows the control fan
  • fig. 5 shows a comparison of the sound intensity emitted by the fan according to the invention and the control fan in accordance with PN-EN 61260-1:2015-01
  • fig. 6 shows a comparison of the sound spectrum emitted by the fan according to the invention and by the control fan, obtained by the Fourier analysis of the signal recorded at the output of an amplifier with the Z frequency characteristics.
  • the axial fan according to the invention is designed to be mounted in a horizontal or vertical position in various cooling systems, e.g. it can be mounted in a computer enclosure. Whereby, in the field of computer cooling, the fan according to the invention may be used, for example, in air cooling of the CPU, liquid cooling of the CPU and other computer components like computer PSUs.
  • the axial fan according to the invention is mounted horizontally in the computer enclosure and is used for liquid cooling of the computer processor (i.e. the CPU).
  • an axial fan comprises a frame 1, a motor and a plurality of blades 2 extending from the rotor towards the frame 1.
  • said frame 1 comprises a support part la and slats lb connected to the support part la and fixing the motor and a plurality of fan blades 2 mounted on the motor rotor equipped with a fluid dynamic bearing (FDB).
  • FDB fluid dynamic bearing
  • Each of the plurality of blades 2 has a uniformly terminated ridge edge 3 and a substantially serrated leading edge 4 (which is indicated by a dashed line in fig. 1) provided with serrations 5, which provide the serrated leading edge 4 with a shape approximating a vanishing sine wave.
  • the spacing between the individual serrations 5 is 1/7 of the length of the leading edge 4 of the blade 2.
  • the sound generated by the low-speed axial fan according to embodiment 1 consists of tonal components and broadband noise with a continuous spectrum.
  • the main source of the tonal components is the movement of the rotor.
  • the fan generates tonal noise consisting of tones corresponding to the rotor blade passing frequency (BPF) and multiples of the BPF.
  • BPF rotor blade passing frequency
  • Other sources of tonal noise are aerodynamic effects: stall cycling around the rotor and variations in rotor blade forces due to blade position relative to asymmetrical parts of the fan cowl.
  • the sources of broadband random frequency noise are mainly aerodynamic effects: turbulence due to geometric imperfections of the rotor, random fluctuations in pressure and velocity of the air stream entering the fan, and air vortices at the ends of the rotor blades and behind the trailing edge of the rotor blades ( Neise , W and Michel, U, AERODYNAMIC NOISE OF TURBOMACHINES, German Aerospace Center, Berlin 1994; Moreau, S. et al, Toward the prediction of low-speed fan noise, Center for Turbulence Research 2006).
  • the intensity of tonal noise is usually concentrated in the low frequency band, from 100 to 2000 Hz (fig. 3).
  • the fan in question with a speed of 1600 rpm and a rotor with 9 blades, generates tonal noise with component frequencies of 240 Hz and subsequent multiples of 240 Hz.
  • the tonal components In the 100-1000 Hz band, the tonal components have a much higher intensity than the broadband noise.
  • the intensity of the sound is dominated by the broadband noise.
  • sources of tonal sound are easier to locate in space.
  • the sense of hearing relies, among other things, on the phase difference between the sound reaching the right and the left ear. This difference is more difficult to detect if the sound does not consist of a pure tone.
  • a tonal sound masks the audibility and recognition of other sounds of a frequency occupying the same critical band, i.e. of similar frequency.
  • Broadband noise is perceived as quieter, is more difficult to locate, is less likely to mask the audibility of other ambient sounds, and is more likely to itself be masked by ambient sounds. For these reasons, it is desirable to reduce the tonal noise produced by the fan, especially in octaves where the broadband noise is much less intense.
  • Replacing tonal noise with broadband noise of the same acoustic power reduces the annoyance of the perceived sound. As high- frequency sounds are more strongly attenuated by air ( Lamancusa , J. S., Noise control, Pennsylvania State University, State College 2009; https://www.mne.psu. edu/lamancusa/me458/l 0 _osp.pdf). swapping noise for another noise with the same acoustic power but with a higher frequency band is also beneficial.
  • test fan the sound spectrum emitted by the fan according to the invention was compared to that emitted by an identical fan with blades with curved leading edges without serrations (control fan) (fig. 4).
  • the tested fans were mounted on a test stand consisting of:
  • the test rig was placed in an anechoic chamber with dimensions of 110x 110x 170 cm.
  • the fans were placed at a distance of 30 cm from the microphone, in such a way that the fan axis and the microphone axis overlapped.
  • the fans were operated at a speed of 1600 rpm ( ⁇ 1%) powered by 12.0 V DC and controlled by a 25 kHz PWM waveform with a maximum level of 4.4 V, as intended.
  • the sound of the running fan was collected by a microphone and a Sonopan preamplifier set to the Z-correction characteristic.
  • the course of the signal after it passed the preamplifier was recorded with an oscilloscope at a sampling frequency of 100 kHz for 12 seconds.
  • the recorded signal was subjected to computer analysis with a view to detecting the tonal and stochastic components.
  • the analysis has shown that the sinusoidal shaping of the leading edge of the rotor blades eliminates the tonal sound at a frequency of about 315 Hz, the intensity of which was higher than that of any other tonal component of the emitted sound.
  • the said shaping also eliminates a tonal sound at around 4350 Hz with a distinctive intensity.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

L'invention concerne un ventilateur axial à faible vitesse destiné à être monté dans une position horizontale ou verticale, en particulier dans des enceintes d'ordinateur, le ventilateur comprenant un cadre, un moteur et une pluralité de pales s'étendant du rotor vers le cadre, le cadre comprenant une partie de support et des lamelles reliées à la partie de support et fixant le moteur et la pluralité de pales de ventilateur montées sur le rotor de moteur ; caractérisé en ce que chaque pale, parmi la pluralité de pales, comporte un bord de crête fini de manière uniforme et un bord d'attaque sensiblement dentelé muni de dentelures, l'espacement entre les creux étant de 1/10 à 1/5 de la longueur du bord d'attaque dentelé de la pale ; tandis que le rotor est équipé d'un palier FDB.
PCT/IB2022/052728 2021-03-25 2022-03-24 Ventilateur axial à bords d'attaque de pale dentelés WO2022201103A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP22723182.6A EP4314569A1 (fr) 2021-03-25 2022-03-24 Ventilateur axial à bords d'attaque de pale dentelés

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PLP.437413 2021-03-25
PL437413A PL437413A1 (pl) 2021-03-25 2021-03-25 Niskoobrotowy wentylator osiowy do stosowania do montażu w pozycji poziomej lub pionowej, w szczególności w obudowach komputerowych

Publications (1)

Publication Number Publication Date
WO2022201103A1 true WO2022201103A1 (fr) 2022-09-29

Family

ID=81648615

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2022/052728 WO2022201103A1 (fr) 2021-03-25 2022-03-24 Ventilateur axial à bords d'attaque de pale dentelés

Country Status (3)

Country Link
EP (1) EP4314569A1 (fr)
PL (1) PL437413A1 (fr)
WO (1) WO2022201103A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009068361A (ja) * 2007-09-11 2009-04-02 Samsung Electronics Co Ltd 送風機
WO2012039092A1 (fr) * 2010-09-21 2012-03-29 三菱電機株式会社 Soufflante à flux axial
US20130121859A1 (en) * 2011-11-10 2013-05-16 Nidec Corporation Bearing apparatus and fan
WO2016042698A1 (fr) * 2014-09-18 2016-03-24 株式会社デンソー Soufflante
EP3321511A1 (fr) * 2015-08-10 2018-05-16 Mitsubishi Electric Corporation Soufflante, et dispositif de conditionnement d'air sur lequel celle-ci est montée

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009068361A (ja) * 2007-09-11 2009-04-02 Samsung Electronics Co Ltd 送風機
WO2012039092A1 (fr) * 2010-09-21 2012-03-29 三菱電機株式会社 Soufflante à flux axial
US20130121859A1 (en) * 2011-11-10 2013-05-16 Nidec Corporation Bearing apparatus and fan
WO2016042698A1 (fr) * 2014-09-18 2016-03-24 株式会社デンソー Soufflante
EP3321511A1 (fr) * 2015-08-10 2018-05-16 Mitsubishi Electric Corporation Soufflante, et dispositif de conditionnement d'air sur lequel celle-ci est montée

Also Published As

Publication number Publication date
EP4314569A1 (fr) 2024-02-07
PL437413A1 (pl) 2022-09-26

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