CA1327553C - Blade for a propeller for a fan in an automobile, imparted with a falciform configuration - Google Patents
Blade for a propeller for a fan in an automobile, imparted with a falciform configurationInfo
- Publication number
- CA1327553C CA1327553C CA000571565A CA571565A CA1327553C CA 1327553 C CA1327553 C CA 1327553C CA 000571565 A CA000571565 A CA 000571565A CA 571565 A CA571565 A CA 571565A CA 1327553 C CA1327553 C CA 1327553C
- Authority
- CA
- Canada
- Prior art keywords
- blade
- propeller
- foot
- head
- axis
- 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.)
- Expired - Fee Related
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
-
- 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
Abstract
ABSTRACT OF THE DISCLOSURE
The blade for a propeller constituted by a hub to which the feet are fixed has a leading edge and a trailing edge which are formed by two arcs having respective mean radii of curvateure which are different and interconnected without an angular point. These edges are both curved in the downstream direction and define a blade which narrows from the axis to the periphery of the propeller. The blade may be used in propellers of motorized fans associated with automobile vehicles.
The blade for a propeller constituted by a hub to which the feet are fixed has a leading edge and a trailing edge which are formed by two arcs having respective mean radii of curvateure which are different and interconnected without an angular point. These edges are both curved in the downstream direction and define a blade which narrows from the axis to the periphery of the propeller. The blade may be used in propellers of motorized fans associated with automobile vehicles.
Description
The present invention relates to blades for the propeller of motori~ed fans employed in par~icular in the automobile indu~.ry.
Propellers are used in many technical fields and in particular for fans. This is the case in the automobile industry in which motorized fans are associat~d with cooling radiators of heat engines~
As is known, each blade of a propeller, in particular of a motorized fan unit~ produces a slip-stream which rotates at the speed o rotation of the propeller. This slip-stream generates a sound which is intense when it encounters a fixed obstacle. This is for example the case when the slip-stream encounters the arms of supports of a motorized fan unit which support the latter for maintaining it in a fixed , position relative to the radiator with which it is ',.,~ associated.
Such axial fans produce a highly turbulent slip-stream ;~ 20 whlch generates considerable noise. Indeed, when the slip-~.
stream of a blade passes in front of a support arm, it produces a mechanical impulse which results in a particular noise which is added to the aerodynamic noise or to the noise of the driving motor.
The interest of reducing the noise produced by such a rotating slip-stream which passes in front of the support arms of the fan will of course be understood if a more ,~, , ' ~
:`
:: ,, ~ ;
.~ , ' ; ' .
. .
silent operation is to be obtained.
The structure of the slip-stream produced by a blade is a function of the aerodynamic definition of the latter and in particular of the evolution of the range of speeds in the passage formed between two neighbouring blades. More specifically, it has been found that these slip-streams may create around the support arms non-stationary systems which are sources of noise if the gap between the trailing sdgss of the blades and the support arms is relatively small. It has been found that the slip~stream located in the extension of the trailing edges of the blades disappears relatively rapidly at a certain distance in the downstream direction from the trailing edge owing to the damping due to the viscosity of the air and that this slip-stream is then lost in the general turbulence of the flow, : Thus it can be seen that if it is possible to increase `i the distance between the trailing edge of such a propeller blade and the support arms supporting it without increasing ~i the overall axial size of the assembly, the noise produced .~.
by the slip-stream when it encounters the fixing arms or the like may be reduc d.
-~ An object of the invention is to provide a propeller `~ blade in particular of a motorized fan unit of use in the ~ automobile, whose geometry imparts thereto,at relatively ., high rotational regimes, high aerodynamic performances and a considerable level of silence.
To achieve this result, it is arranged that at least the : . ' ' ' ;'` ~
preponderant section of -the blade which generates acoustic noise be as far as possible from the fixed obstacles of the support arms or the like.
According to an object of the present invention, there is provided a blade for a propeller for a fan in an automobile vehicle, the propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of the blade and a central hub connected a foot of the blade, the blade having a leading edge and a trailing edge lo which are both curved and arranged relative to each other in such a manner as to impart to the blade a falciform configuration narrowing from th0 foot to the head, wherein respective concavities of the curved leading and krailing edyes face in a downstream direction with respec-t to a direction of a fluid flow through the propeller, the trailing edge being formed by two arcs which have different respective mean radii of curvature and which are interconnected without an anyular point, and this being in accordance with a projection on an axial plane of the central hub.
-~ Preferahly, such a ~lade is intended for a ; propeller which comprises an outer cowling consisting of a peripheral sleeve to which the blacle heads are fixed.
According to another objet of the present - 25 invention, there is provided a blade for a propeller for a ;`~ motorized fan for cooling an automobile vehicle, the :~ propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of the blade and a central hub connected a foot of the blade, the blade : 30 having a leading edge and a trailing edge which are both ~ curved and arranged xelative to each other in such a manner ;~ as to impart to the blade a falciform configuration ` narrowing from the foot to the head, wherein respective . .
~., .. . . . .
. - 3a -concavities of the curved 10ading and trailing edges face in a downstream direction with respsct to a direciton of a fluid flow through the propeller, the trailing edge being formed by two arcs with have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of the central hub According to another objet of the present invention, there is provided a propeller for a fan in an lo automobile vehicle, the propeller being rotatable about an axis and comprising a peripheral outer part in the form of a sleeve, a cenkral hub, at least one blade having a foot connected to the hub, a head connected to the sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as -to impart to the blade a falciform configuration narrowing from the foot to the head in a direction parallel to the axis, wherein the lengths of the foot and head measured in a direction parallel to the axis which are in a ratio on the . 20 order of 0,4, and wherein respective concavities of the . curved leading and trailing edges face in a downstream direction with respect to a direction of a fluid flow through the propeller, the trailling edge being formed by two arcs which have different respective mean radii of . 25 curvature and which are interconnected without an angular point, and this being in accordance with a projection on an : axial plane of the central hub.
According to another objet of the present invention, there is provided a propeller for a motorized fan for cooling an automobile radiator, the propeller being ~ rotatable about an axis and comprising a peripheral outer :~ part in the form of a sleeve, a central hub, at least one . blade haviny a foot connected to the hub, a head connected p~ ' - ~ ' ~, - 3b -to the sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as to impart to the blade a falciform configuration narrowing from the foot to the head in a direction parallel to the axis, wherein the lengths of the foot and head measured in a direction parallel to the axis which are in a ratio on the order of 0,4, and wherein respective concavities of the curved leading and trailing edges face in a downstream direction with respect to a direction of a lo fluid flow through the propeller, the trailing ~dge being formed by two arcs which have differen~ respective mean radii of curvature and which are interconnected without an angular poink, and this being in accordance with a projection on an axial plane of the central hub.
. 15 Further features of the invention will be apparent ~: from the description and claims with reference to the ~ accompanying drawing which is given solely by way of example ; and in which:
:,.,. /
, i /
, /
j ~ .
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.,, . /
~ /
; ~. / .
'~""` /
.,'.
"' A
. .. .
~, Fig. 1 is a partial diagrammatic axial meridian sectional view of a propeller blade according to the invention,and Figs~ 2A and 2B respectively illustrate the noise produced by a propeller according to the invention and the noise produced by a propeller of the prior art, the characteristics of speed and flow and the dimensions of which aresubstantially the same~
As the propeller blades for motorized fans are well known in the art, there will only be described that which is related to the invention. For the rest of the structure~
l one skilled in the art will derive from conventional .~, solutions available to him arrangements for solving specific problems he encounters.
It will be assumed hereinafter that the blade for the :, propeller according to the invention is adapted to be used for producing a propeller for a fan of a cooling radiator of automobile heat enginesO However~ it will be clear that such a blade which permits reducing the noise produced by ~-~ 20 its slip-stream when the latter encounters a fixed obstacle . located at a short distance from its trailing edge and in ~ the slip-stream of the latter, may be employed in other ,~ applications.
As can be seen in Fig. 1, a blade 10 is part of a propeller comprising a central hub 20 and a peripheral sleeve 30. The feet 12 and the heads 13 of the blades are fixed to the hub and sleeve respectively.
~ , . . .
The blade 10 has a leading edge 14 and a trailing edge 15. Support arms or the like adapted to suppsrt the motori~ed fan are not shown.
As can be seen in the illustration7 the leading edge 14 5 and the trailing edge 15 are both curved and are so arranged relative to each other as to impart a falciform or sickle-shaped configuration which narrows from the foot to the head of the blades As can be seen in the drawing, the respective ; concavities of the leading edge 14 and trailing edge 15 face lO in the downstream direction with respect to the direction of flow of the fluid diagrammatically represented by the arrow~
';;1 Note that the trailing edge 15 is formed by two arcs ~, 152, 153 whose respective mean radii o~ curvature r2 andf3 are 15 different and connected without an angular point. These arcs of a curvature 152 and 153 are arcs of a circle ox arcs .:, of a cone having for example centres 2 and 03 respectively.
I In order to achieve the maximum reduction of the noise without loss of efficiency relative to a conventional ~., ; 20 propeller it has been found that the mean radius of curvature f 2 of the arc 152 located adjacent to the foot 12 of the blade must be smaller than the mean rad1us of curvature f 3 of the arc 153 located adjacent to head 13 of the blade. Preferably, this radius ~ 2 of the arc 152 is 25 appoximately between about one quarter and one third of the outside diameter D2 of the hub 20 measured at the foot of the blade.
, .
~' ' ' "'':' .
For example, for a hub 20 whose axial length or thickness is on the order of 55 mm, there is adopted for the radius ~ 2 of the arc 152 located adjacent to the blade foot 12, a value approximately between one quarter and one third of the diameter of the sleeve 30 measured at the head of the blade. For an axial length of the hub 20 which does not exceed 38 mm there is chosen for the radius f 2 a value equal to about one half of this diameter of the sleeve.
This especially concerns the median sections of the lO blade which produce the most energy from the point of view of acoustic emission. These sections occupy approximately a zone which is roughly equally clistributed between the foot and the head of the blade and extends over about three quarters of the latter.
According to the invention~ the falciform configuration ~i of the blade is such that the ratio between the lengths L2, ¦ L3 of the blade feet 12 and blade heads 13 respectively is , on the order of about 0.4.
`~ The indicated dimensions are orders of magnitudeO For i~! 20 ~xample, as noticed, the mean radius of curvature f3 of the arc 153 lo~ated adjacent to the blade head 13 is a function of the axial length L of the hub 20.
In order to illustrate the improvement afforded by a propeller blade according to the invention, its sound characteristics are compared with those of a conventional blade diagrammatically illustrated in Fig. 1 in dot-dash lines.
. . ...................... .
. . ~ . .
~ .
.
These blades according to the invention and according to the prior art have geometries calculated in accordance with conventional techniques in such a manner as to have similar aerodynamic performances as concerns the flows and static pressure. Only the profiles of the curved leading and trailing edges according to the invention and rectilinear leading and trailing edges according to the prior art change.
~' For example, these propellers produce a flow of 1700 cu.
m/h with a static pessure of 15 mm of a water head when the diameter of the blade head is 305 mmand the diameter of the blade foot 124 mm and when the conventional propeller is rotated at 2580 rpm and the propeller according to the invention is rotated at 2650 rpm. These two propellers are associated with the same motor and the same vehicle radiator ~I by means of support arms which have the same configuration.
ThP performances of these two propellers are respectively illustrated in Fig. 2A in respect of the . .~
propeller accoxding to the invention and Fig4 2B in respect of a conventional propeller. In these graphs, the sound frequencies in kHz are plotted as abscissae and the sound level in dB are plotted as ordinates. The reduction in the overall sound level for a propeller according to the invention is immediately obvious; since this level is 61.5 dB whereas it is 66.5 dB for a conventional propeller.
In Fig. 2, the acoustic pressure levels are analysed as thirds of an octave and the level of the overall noise is : ' ' ~'' '''''' -~ ' shown weighted in accordance with the standard A.
It can also be seen that the maximum is reached at a lower frequency ~ith a blade according to the invention.
Owing to the invention, it was possible to increase the axial distance between the trailing edge of the blade of the propeller and the fixed obstacles formed by the support arms of the motorized fan or the like which produce noiseO The invention results in a relatively low sound level by the ; displacement of the frequency spectrum of the acoustic energy in the direction of the frequencies which correspond ,:~
to less sensitivity on the part of the human ear.
,., 1 .,, ,:. ' `."''", ~' -' ;~
" , . ,5 .'~
Propellers are used in many technical fields and in particular for fans. This is the case in the automobile industry in which motorized fans are associat~d with cooling radiators of heat engines~
As is known, each blade of a propeller, in particular of a motorized fan unit~ produces a slip-stream which rotates at the speed o rotation of the propeller. This slip-stream generates a sound which is intense when it encounters a fixed obstacle. This is for example the case when the slip-stream encounters the arms of supports of a motorized fan unit which support the latter for maintaining it in a fixed , position relative to the radiator with which it is ',.,~ associated.
Such axial fans produce a highly turbulent slip-stream ;~ 20 whlch generates considerable noise. Indeed, when the slip-~.
stream of a blade passes in front of a support arm, it produces a mechanical impulse which results in a particular noise which is added to the aerodynamic noise or to the noise of the driving motor.
The interest of reducing the noise produced by such a rotating slip-stream which passes in front of the support arms of the fan will of course be understood if a more ,~, , ' ~
:`
:: ,, ~ ;
.~ , ' ; ' .
. .
silent operation is to be obtained.
The structure of the slip-stream produced by a blade is a function of the aerodynamic definition of the latter and in particular of the evolution of the range of speeds in the passage formed between two neighbouring blades. More specifically, it has been found that these slip-streams may create around the support arms non-stationary systems which are sources of noise if the gap between the trailing sdgss of the blades and the support arms is relatively small. It has been found that the slip~stream located in the extension of the trailing edges of the blades disappears relatively rapidly at a certain distance in the downstream direction from the trailing edge owing to the damping due to the viscosity of the air and that this slip-stream is then lost in the general turbulence of the flow, : Thus it can be seen that if it is possible to increase `i the distance between the trailing edge of such a propeller blade and the support arms supporting it without increasing ~i the overall axial size of the assembly, the noise produced .~.
by the slip-stream when it encounters the fixing arms or the like may be reduc d.
-~ An object of the invention is to provide a propeller `~ blade in particular of a motorized fan unit of use in the ~ automobile, whose geometry imparts thereto,at relatively ., high rotational regimes, high aerodynamic performances and a considerable level of silence.
To achieve this result, it is arranged that at least the : . ' ' ' ;'` ~
preponderant section of -the blade which generates acoustic noise be as far as possible from the fixed obstacles of the support arms or the like.
According to an object of the present invention, there is provided a blade for a propeller for a fan in an automobile vehicle, the propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of the blade and a central hub connected a foot of the blade, the blade having a leading edge and a trailing edge lo which are both curved and arranged relative to each other in such a manner as to impart to the blade a falciform configuration narrowing from th0 foot to the head, wherein respective concavities of the curved leading and krailing edyes face in a downstream direction with respec-t to a direction of a fluid flow through the propeller, the trailing edge being formed by two arcs which have different respective mean radii of curvature and which are interconnected without an anyular point, and this being in accordance with a projection on an axial plane of the central hub.
-~ Preferahly, such a ~lade is intended for a ; propeller which comprises an outer cowling consisting of a peripheral sleeve to which the blacle heads are fixed.
According to another objet of the present - 25 invention, there is provided a blade for a propeller for a ;`~ motorized fan for cooling an automobile vehicle, the :~ propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of the blade and a central hub connected a foot of the blade, the blade : 30 having a leading edge and a trailing edge which are both ~ curved and arranged xelative to each other in such a manner ;~ as to impart to the blade a falciform configuration ` narrowing from the foot to the head, wherein respective . .
~., .. . . . .
. - 3a -concavities of the curved 10ading and trailing edges face in a downstream direction with respsct to a direciton of a fluid flow through the propeller, the trailing edge being formed by two arcs with have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of the central hub According to another objet of the present invention, there is provided a propeller for a fan in an lo automobile vehicle, the propeller being rotatable about an axis and comprising a peripheral outer part in the form of a sleeve, a cenkral hub, at least one blade having a foot connected to the hub, a head connected to the sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as -to impart to the blade a falciform configuration narrowing from the foot to the head in a direction parallel to the axis, wherein the lengths of the foot and head measured in a direction parallel to the axis which are in a ratio on the . 20 order of 0,4, and wherein respective concavities of the . curved leading and trailing edges face in a downstream direction with respect to a direction of a fluid flow through the propeller, the trailling edge being formed by two arcs which have different respective mean radii of . 25 curvature and which are interconnected without an angular point, and this being in accordance with a projection on an : axial plane of the central hub.
According to another objet of the present invention, there is provided a propeller for a motorized fan for cooling an automobile radiator, the propeller being ~ rotatable about an axis and comprising a peripheral outer :~ part in the form of a sleeve, a central hub, at least one . blade haviny a foot connected to the hub, a head connected p~ ' - ~ ' ~, - 3b -to the sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as to impart to the blade a falciform configuration narrowing from the foot to the head in a direction parallel to the axis, wherein the lengths of the foot and head measured in a direction parallel to the axis which are in a ratio on the order of 0,4, and wherein respective concavities of the curved leading and trailing edges face in a downstream direction with respect to a direction of a lo fluid flow through the propeller, the trailing ~dge being formed by two arcs which have differen~ respective mean radii of curvature and which are interconnected without an angular poink, and this being in accordance with a projection on an axial plane of the central hub.
. 15 Further features of the invention will be apparent ~: from the description and claims with reference to the ~ accompanying drawing which is given solely by way of example ; and in which:
:,.,. /
, i /
, /
j ~ .
: / -.. ,, /
.,, . /
~ /
; ~. / .
'~""` /
.,'.
"' A
. .. .
~, Fig. 1 is a partial diagrammatic axial meridian sectional view of a propeller blade according to the invention,and Figs~ 2A and 2B respectively illustrate the noise produced by a propeller according to the invention and the noise produced by a propeller of the prior art, the characteristics of speed and flow and the dimensions of which aresubstantially the same~
As the propeller blades for motorized fans are well known in the art, there will only be described that which is related to the invention. For the rest of the structure~
l one skilled in the art will derive from conventional .~, solutions available to him arrangements for solving specific problems he encounters.
It will be assumed hereinafter that the blade for the :, propeller according to the invention is adapted to be used for producing a propeller for a fan of a cooling radiator of automobile heat enginesO However~ it will be clear that such a blade which permits reducing the noise produced by ~-~ 20 its slip-stream when the latter encounters a fixed obstacle . located at a short distance from its trailing edge and in ~ the slip-stream of the latter, may be employed in other ,~ applications.
As can be seen in Fig. 1, a blade 10 is part of a propeller comprising a central hub 20 and a peripheral sleeve 30. The feet 12 and the heads 13 of the blades are fixed to the hub and sleeve respectively.
~ , . . .
The blade 10 has a leading edge 14 and a trailing edge 15. Support arms or the like adapted to suppsrt the motori~ed fan are not shown.
As can be seen in the illustration7 the leading edge 14 5 and the trailing edge 15 are both curved and are so arranged relative to each other as to impart a falciform or sickle-shaped configuration which narrows from the foot to the head of the blades As can be seen in the drawing, the respective ; concavities of the leading edge 14 and trailing edge 15 face lO in the downstream direction with respect to the direction of flow of the fluid diagrammatically represented by the arrow~
';;1 Note that the trailing edge 15 is formed by two arcs ~, 152, 153 whose respective mean radii o~ curvature r2 andf3 are 15 different and connected without an angular point. These arcs of a curvature 152 and 153 are arcs of a circle ox arcs .:, of a cone having for example centres 2 and 03 respectively.
I In order to achieve the maximum reduction of the noise without loss of efficiency relative to a conventional ~., ; 20 propeller it has been found that the mean radius of curvature f 2 of the arc 152 located adjacent to the foot 12 of the blade must be smaller than the mean rad1us of curvature f 3 of the arc 153 located adjacent to head 13 of the blade. Preferably, this radius ~ 2 of the arc 152 is 25 appoximately between about one quarter and one third of the outside diameter D2 of the hub 20 measured at the foot of the blade.
, .
~' ' ' "'':' .
For example, for a hub 20 whose axial length or thickness is on the order of 55 mm, there is adopted for the radius ~ 2 of the arc 152 located adjacent to the blade foot 12, a value approximately between one quarter and one third of the diameter of the sleeve 30 measured at the head of the blade. For an axial length of the hub 20 which does not exceed 38 mm there is chosen for the radius f 2 a value equal to about one half of this diameter of the sleeve.
This especially concerns the median sections of the lO blade which produce the most energy from the point of view of acoustic emission. These sections occupy approximately a zone which is roughly equally clistributed between the foot and the head of the blade and extends over about three quarters of the latter.
According to the invention~ the falciform configuration ~i of the blade is such that the ratio between the lengths L2, ¦ L3 of the blade feet 12 and blade heads 13 respectively is , on the order of about 0.4.
`~ The indicated dimensions are orders of magnitudeO For i~! 20 ~xample, as noticed, the mean radius of curvature f3 of the arc 153 lo~ated adjacent to the blade head 13 is a function of the axial length L of the hub 20.
In order to illustrate the improvement afforded by a propeller blade according to the invention, its sound characteristics are compared with those of a conventional blade diagrammatically illustrated in Fig. 1 in dot-dash lines.
. . ...................... .
. . ~ . .
~ .
.
These blades according to the invention and according to the prior art have geometries calculated in accordance with conventional techniques in such a manner as to have similar aerodynamic performances as concerns the flows and static pressure. Only the profiles of the curved leading and trailing edges according to the invention and rectilinear leading and trailing edges according to the prior art change.
~' For example, these propellers produce a flow of 1700 cu.
m/h with a static pessure of 15 mm of a water head when the diameter of the blade head is 305 mmand the diameter of the blade foot 124 mm and when the conventional propeller is rotated at 2580 rpm and the propeller according to the invention is rotated at 2650 rpm. These two propellers are associated with the same motor and the same vehicle radiator ~I by means of support arms which have the same configuration.
ThP performances of these two propellers are respectively illustrated in Fig. 2A in respect of the . .~
propeller accoxding to the invention and Fig4 2B in respect of a conventional propeller. In these graphs, the sound frequencies in kHz are plotted as abscissae and the sound level in dB are plotted as ordinates. The reduction in the overall sound level for a propeller according to the invention is immediately obvious; since this level is 61.5 dB whereas it is 66.5 dB for a conventional propeller.
In Fig. 2, the acoustic pressure levels are analysed as thirds of an octave and the level of the overall noise is : ' ' ~'' '''''' -~ ' shown weighted in accordance with the standard A.
It can also be seen that the maximum is reached at a lower frequency ~ith a blade according to the invention.
Owing to the invention, it was possible to increase the axial distance between the trailing edge of the blade of the propeller and the fixed obstacles formed by the support arms of the motorized fan or the like which produce noiseO The invention results in a relatively low sound level by the ; displacement of the frequency spectrum of the acoustic energy in the direction of the frequencies which correspond ,:~
to less sensitivity on the part of the human ear.
,., 1 .,, ,:. ' `."''", ~' -' ;~
" , . ,5 .'~
Claims (12)
1. A blade for a propeller for a fan in an automobile vehicle, said propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of said blade and a central hub connected a foot of said blade, said blade having a leading edge and a trailing edge which are both curved and arranged relative to each other in such a manner as to impart to said blade a falciform configuration narrowing from said foot to said head, wherein respective concavities of said curved leading and trailing edges face in a downstream direction with respect to a direction of a fluid flow through said propeller, said trailing edge being formed by two arcs which have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of said central hub.
2. A blade according to claim 1, wherein at least one of said arcs is an arc of a circle.
3. A blade according to claim 1 or 2, wherein at least one of said arcs is an arc of a cone.
4. A blade according to claim 1, wherein said peripheral outer part is a sleeve.
5. A blade according to claim 1, wherein said foot and said head of said blade have lengths which are in a ratio on the order of 0,4.
6. A blade according to claim 1, wherein said foot and said head of said blade have lengths measured in a direction parallel to said axis which are in a ratio on the order of 0,4.
7. A blade according to claim 1, wherein the mean radius of curvature of the arc located adjacent said foot is smaller than the mean radius of curvature of the arc located adjacent said head.
8. A blade according to claim 1 or 7, wherein the mean radius of curvature of the arc located adjacent said foot is between approximately about one quarter and about one third of the diameter of said hub at said foot.
9. A blade according to claim 1, wherein the mean radius of curvature of the arc located adjacent said head is a function of an axial length of said hub.
10. A blade for a propeller for a motorized fan for cooling an automobile vehicle, said propeller being rotatable about an axis and comprising a peripheral outer part connected to a head of said blade and a central hub connected a foot of said blade, said blade having a leading edge and a trailing edge which are both curved and arranged relative to each other in such a manner as to impart to said blade a falciform configuration narrowing from said foot to said head, wherein respective concavities of said curved leading and trailing edges face in a downstream direction with respect to a direciton of a fluid flow through said propeller, said trailing edge being formed by two arcs with have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of said central hub.
11. A propeller for a fan in an automobile vehicle, said propeller being rotatable about an axis and comprising a peripheral outer part in the form of a sleeve, a central hub, at least one blade having a foot connected to said hub, a head connected to said sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as to impart to said blade a falciform configuration narrowing from said foot to said head in a direction parallel to said axis, wherein the lengths of said foot and head measured in a direction parallel to said axis which are in a ratio on the order of 0,4, and wherein respective concavities of said curved leading and trailing edges face in a downstream direction with respect to a direction of a fluid flow through said propeller, said trailing edge being formed by two arcs which have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of said central hub.
12. A propeller for a motorized fan for cooling an automobile radiator, said propeller being rotatable about an axis and comprising a peripheral outer part in the form of a sleeve, a central hub, at least one blade having a foot connected to said hub, a head connected to said sleeve, and leading and trailing edges which are both curved and arranged relative to each other in such a manner as to impart to said blade a falciform configuration narrowing from said foot to said head in a direction parallel to said axis, wherein the lengths of said foot and head measured in a direction parallel to said axis which are in a ratio on the order of 0,4, and wherein respective concavities of said curved leading and trailing edges face in a downstream direction with respect to a direction of a fluid flow through said propeller, said trailing edge being formed by two arcs which have different respective mean radii of curvature and which are interconnected without an angular point, and this being in accordance with a projection on an axial plane of said central hub.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8709773A FR2617904B1 (en) | 1987-07-09 | 1987-07-09 | FALCIFORM BLADE FOR PROPELLER AND ITS APPLICATION IN PARTICULAR TO MOTOR FANS FOR AUTOMOBILES |
| FR8709773 | 1987-07-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1327553C true CA1327553C (en) | 1994-03-08 |
Family
ID=9353039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000571565A Expired - Fee Related CA1327553C (en) | 1987-07-09 | 1988-07-08 | Blade for a propeller for a fan in an automobile, imparted with a falciform configuration |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4871298A (en) |
| EP (1) | EP0298861B1 (en) |
| JP (1) | JPH0227199A (en) |
| KR (1) | KR890002559A (en) |
| CA (1) | CA1327553C (en) |
| DE (1) | DE3862816D1 (en) |
| ES (1) | ES2022999B3 (en) |
| FR (1) | FR2617904B1 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4971520A (en) * | 1989-08-11 | 1990-11-20 | Airflow Research And Manufacturing Corporation | High efficiency fan |
| DE4127134B4 (en) * | 1991-08-15 | 2004-07-08 | Papst Licensing Gmbh & Co. Kg | diagonal fan |
| ES2128357T3 (en) * | 1991-08-30 | 1999-05-16 | Airflow Res & Mfg | FAN APPLIANCE MISSING FORWARD WITH TILT. |
| US5489186A (en) * | 1991-08-30 | 1996-02-06 | Airflow Research And Manufacturing Corp. | Housing with recirculation control for use with banded axial-flow fans |
| US5244347A (en) * | 1991-10-11 | 1993-09-14 | Siemens Automotive Limited | High efficiency, low noise, axial flow fan |
| US5437541A (en) * | 1993-12-30 | 1995-08-01 | Vainrub; John | Blade for axial fan |
| US5624234A (en) * | 1994-11-18 | 1997-04-29 | Itt Automotive Electrical Systems, Inc. | Fan blade with curved planform and high-lift airfoil having bulbous leading edge |
| US5588804A (en) * | 1994-11-18 | 1996-12-31 | Itt Automotive Electrical Systems, Inc. | High-lift airfoil with bulbous leading edge |
| CN2304777Y (en) * | 1997-05-28 | 1999-01-20 | 韩玮 | Fan with wheel style paddles |
| US6595753B1 (en) * | 1999-05-21 | 2003-07-22 | A. Vortex Holding Company | Vortex attractor |
| US6309178B1 (en) | 1999-09-22 | 2001-10-30 | Young S. Kim | Downstream guiding device for fan-radiator cooling system |
| JP3473549B2 (en) * | 2000-04-28 | 2003-12-08 | 松下電器産業株式会社 | Blower impeller and air conditioner equipped with the blower impeller |
| KR100978594B1 (en) | 2000-06-16 | 2010-08-27 | 로버트 보쉬 코포레이션 | Automotive fan assembly with flared shroud and fan with conforming blade tips |
| JP4085948B2 (en) * | 2003-10-01 | 2008-05-14 | 株式会社デンソー | Cooling fan and blower |
| US7331764B1 (en) | 2004-04-19 | 2008-02-19 | Vee Engineering, Inc. | High-strength low-weight fan blade assembly |
| US20060076120A1 (en) * | 2004-10-12 | 2006-04-13 | Deere & Company, A Delaware Corporation | Cooling system with pre-cleaning |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1228776A (en) * | 1914-04-14 | 1917-06-05 | Carl Alrik Hult | Driving device for boats. |
| US1467227A (en) * | 1921-09-02 | 1923-09-04 | Robert Alfred Blake | Air impeller or propeller |
| US4012172A (en) * | 1975-09-10 | 1977-03-15 | Avco Corporation | Low noise blades for axial flow compressors |
| DE2555200C3 (en) * | 1975-12-09 | 1979-01-04 | Gutehoffnungshuette Sterkrade Ag, 4200 Oberhausen | Axial compressor blade with a leading edge that is swept backwards |
| US4131387A (en) * | 1976-02-27 | 1978-12-26 | General Electric Company | Curved blade turbomachinery noise reduction |
| US4358245A (en) * | 1980-09-18 | 1982-11-09 | Bolt Beranek And Newman Inc. | Low noise fan |
| JPS57140596A (en) * | 1981-02-21 | 1982-08-31 | Eiichi Sugiura | Centrifugal pump |
| JPS5851435U (en) * | 1981-10-05 | 1983-04-07 | 東北金属工業株式会社 | Multilayer ceramic capacitor |
| US4685513A (en) * | 1981-11-24 | 1987-08-11 | General Motors Corporation | Engine cooling fan and fan shrouding arrangement |
| US4459087A (en) * | 1982-06-02 | 1984-07-10 | Aciers Et Outillage Peugeot | Fan unit for an internal combustion engine of automobile vehicle |
| US4569632A (en) * | 1983-11-08 | 1986-02-11 | Airflow Research And Manufacturing Corp. | Back-skewed fan |
| US4548548A (en) * | 1984-05-23 | 1985-10-22 | Airflow Research And Manufacturing Corp. | Fan and housing |
| US4569631A (en) * | 1984-08-06 | 1986-02-11 | Airflow Research And Manufacturing Corp. | High strength fan |
| IT206701Z2 (en) * | 1985-08-02 | 1987-10-01 | Gate Spa | AXIAL FAN PARTICULARLY FOR VEHICLES |
| IT210734Z2 (en) * | 1987-06-03 | 1989-01-11 | Magneti Marelli Spa | AXIAL FAN IMPELLER FOR COOLING THE RADIATOR OF THE REFRIGERATION CIRCUIT OF AN INTERNAL COMBUSTION ENGINE FOR MOTOR VEHICLES |
-
1987
- 1987-07-09 FR FR8709773A patent/FR2617904B1/en not_active Expired - Fee Related
-
1988
- 1988-07-05 DE DE8888401755T patent/DE3862816D1/en not_active Expired - Lifetime
- 1988-07-05 ES ES88401755T patent/ES2022999B3/en not_active Expired - Lifetime
- 1988-07-05 EP EP88401755A patent/EP0298861B1/en not_active Expired - Lifetime
- 1988-07-08 KR KR1019880008507A patent/KR890002559A/en not_active Application Discontinuation
- 1988-07-08 US US07/216,461 patent/US4871298A/en not_active Expired - Fee Related
- 1988-07-08 CA CA000571565A patent/CA1327553C/en not_active Expired - Fee Related
- 1988-07-09 JP JP63171702A patent/JPH0227199A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2617904B1 (en) | 1992-05-22 |
| JPH0227199A (en) | 1990-01-29 |
| KR890002559A (en) | 1989-04-10 |
| ES2022999B3 (en) | 1991-12-16 |
| FR2617904A1 (en) | 1989-01-13 |
| US4871298A (en) | 1989-10-03 |
| DE3862816D1 (en) | 1991-06-20 |
| EP0298861A1 (en) | 1989-01-11 |
| EP0298861B1 (en) | 1991-05-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |