US20190136873A1 - Fan Blade Noise Reducer - Google Patents

Fan Blade Noise Reducer Download PDF

Info

Publication number
US20190136873A1
US20190136873A1 US15/943,927 US201815943927A US2019136873A1 US 20190136873 A1 US20190136873 A1 US 20190136873A1 US 201815943927 A US201815943927 A US 201815943927A US 2019136873 A1 US2019136873 A1 US 2019136873A1
Authority
US
United States
Prior art keywords
fan
fan blade
leading edge
leading
boundary layer
Prior art date
Legal status (The legal status 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 status listed.)
Abandoned
Application number
US15/943,927
Inventor
Jack Milton Sayger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to US15/943,927 priority Critical patent/US20190136873A1/en
Publication of US20190136873A1 publication Critical patent/US20190136873A1/en
Abandoned legal-status Critical Current

Links

Images

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
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/667—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by influencing the flow pattern, e.g. suppression of turbulence
    • 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
    • F04D25/08—Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
    • 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
    • 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
    • F04D29/388—Blades characterised by construction
    • 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

  • FIG. 1 Front view and end view looking at tubing attached on fan blade leading edge.
  • the leading edge method prototype setup used a commercial 4-blade stamped sheet metal shop fan. Fan noise was a major issue during use.
  • Blade Thickness 0.70′′
  • the flow rate drop was not significant for fan's intended application. Noise level drop was significant and greater than could be associated with RPM drop alone.
  • leading edge radius in this example, increasing the leading edge radius to 0.25′′ from 0.70′′ (28%) where 0.25′′ is defined as Leading Edge Radius/Blade Chord Length achieved these results.

Landscapes

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

Abstract

The leading edge method improves fan blade aerodynamics, which reduces energy lost into the airflow as acoustic noise. This results in a quieter fan, with no significant change to air moving capability. This is accomplished by increasing the radius of the fan blade leading edge, and by ensuring that any laminar boundary layer existing over the fan blade is tripped into a more energetic, and less likely to separate, turbulent boundary layer. Most fan blades are not fabricated with aerodynamic (airfoil) cross sections. Typically, they are either stamped from sheet stock, or molded out of thin material, in both cases with “sharp” leading edges with small leading-edge radius compared to fan blade chord length. Airfoils designed to operate at the Reynolds-numbers applicable to fan blades eschew sharp leading edges for large, rounded leading edges to control the surface pressure distributions and permit operation over a wide angle of attack range without boundary layer separation. The leading edge treatment in this patent application serves the purpose of increasing the fan leading edge radius without scrapping the entire fan blade and replacing it with a proper low Reynolds-numbers airfoil shape.

Description

    BACKGROUND
  • To reduce fan size it is necessary to increase fan rpm to maintain the same airflow on such items as shop fans, ac fans, computer fans, etc.. In doing so the fan creates unwanted noise due to leading edge aerodynamic deficiencies. This is a simple fix to this unwanted noise.
    • BRIEF SUMMARY
  • Reduce fan noise by altering fan blade leading edge radius shape and size. Applicable as an aftermarket fix to fan blades, an additional step during blade production, or can be formed directly into the blade.
    • DESCRIPTION OF DRAWING
  • FIG. 1 Front view and end view looking at tubing attached on fan blade leading edge.
    •  DETAILED DESCRIPTION
  • The leading edge method prototype setup used a commercial 4-blade stamped sheet metal shop fan. Fan noise was a major issue during use.
  • Fan Blades: 4
  • Blade Span: 12.75″
  • Chord: 6″
  • Blade Thickness: 0.70″
  • Leading edge method applied: 0.25 OD, 0.125 ID round rubber tubing, full span of each blade. Results: Noise level drop 6%./RPM drop 0.018%/CFM drop 6%.
  • The flow rate drop was not significant for fan's intended application. Noise level drop was significant and greater than could be associated with RPM drop alone.
  • In this example, increasing the leading edge radius to 0.25″ from 0.70″ (28%) where 0.25″ is defined as Leading Edge Radius/Blade Chord Length achieved these results. Apply method along leading edge of fan. Tip region is more critical than root region but best results occur with full span treatment. Circular/tubular shape of method is simple but not required as long as leading edge radius is increased to all blades.

Claims (4)

I claim:
1. Altering the geometric shape and size with various materials or by production methods of the leading edge of a fan blade will change the aerodynamics and harmonics of the fan thus significantly reducing fan noise with insignificant loss of cfm or rpm.
2. The process in claim 1 wherein a piece of 0.250D/0.125 ID round rubber tubing is split on one side and attached to the leading edge of all fan blades of a fan to achieve said results.
3. The process in claims 1 and 2 wherein various materials shaped so they increase the leading edge radius can be substituted to achieve said results.
4. The process in claim 1 wherein the fan blade manufacture can alter the fan blade to achieve said results.
US15/943,927 2017-11-03 2018-04-03 Fan Blade Noise Reducer Abandoned US20190136873A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/943,927 US20190136873A1 (en) 2017-11-03 2018-04-03 Fan Blade Noise Reducer

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201762581596P 2017-11-03 2017-11-03
US15/943,927 US20190136873A1 (en) 2017-11-03 2018-04-03 Fan Blade Noise Reducer

Publications (1)

Publication Number Publication Date
US20190136873A1 true US20190136873A1 (en) 2019-05-09

Family

ID=66326889

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/943,927 Abandoned US20190136873A1 (en) 2017-11-03 2018-04-03 Fan Blade Noise Reducer

Country Status (1)

Country Link
US (1) US20190136873A1 (en)

Similar Documents

Publication Publication Date Title
DK1588024T3 (en) Cooling fan with reinforced wing
WO2007086908A3 (en) Rotor blade for a high speed rotary-wing aircraft
EP2711558A3 (en) Propeller fan
EP3168459B1 (en) Vortex generator, wind turbine blade, and wind turbine power generating apparatus
CN104564804B (en) The design method of wind wheel blade and tubular wine wheel and wind wheel blade
CN106050739A (en) High-performance wing section for cooling fan
EP2957766A1 (en) Pressure side stall strip for wind turbine blade
CN203593160U (en) Wing structure
CN204371773U (en) Centrifugal fan impeller
US20190136873A1 (en) Fan Blade Noise Reducer
MX366512B (en) Hair care device.
CN116838643A (en) Fan blade and fan
US11236759B2 (en) Contoured fan blades and associated systems and methods
CN204344521U (en) Centrifugal fan impeller
CN100400375C (en) Aerofoil with blunt tail edge
CN105298912B (en) Bulge leading edge inlet guiding blade
CN207064139U (en) Wind generator set blade
US20200070956A1 (en) Aerodynamic Regulation of Airscrew-, Fan- and Wind Turbine Blades with Bores and/or Cutting and/or Notching
CN105787217B (en) A kind of optimum design method of aircraft ripple aerofoil profile
CN109209989B (en) Centrifugal fan and range hood
AU2018101230B4 (en) Aerodynamic Regulation of Airscrew-, Fan- and Wind Turbine Blades with Bores and/or Cutting and/or Notching
CN205013369U (en) Fan wheel and fan
CA3027330C (en) Aircraft wing with reduced friction drag
CN203835642U (en) Wind turbine blade
CN115324929B (en) Motor fan blade and motor fan

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION