WO2012062249A1

WO2012062249A1 - Method for influencing the flow behavior of turbomachines, in particular blower devices or suction devices and associated blower device or suction device

Info

Publication number: WO2012062249A1
Application number: PCT/DE2011/001599
Authority: WO
Inventors: Georg E. Koppenwallner
Original assignee: Koppenwallner Georg E
Priority date: 2010-06-08
Filing date: 2011-06-08
Publication date: 2012-05-18
Also published as: DE102010023017A1; EP2580481A1

Abstract

The invention relates to a method for influencing the flow behavior of turbomachines, in particular blower devices or suction devices, wherein the turbomachine has a surface that guides the flow and that has at least one structured surface section (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 515). Longitudinal vortices, by means of which the flow is structured, are advantageously created by means of a structured surface section (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 515) at least in the surface areas of the turbomachine in which the flow separates from the surface or turbulent flows occur.

Description

Method for influencing the flow behavior of machines, in particular blower or suction devices and associated blower or suction device

The invention relates to a method for influencing the flow behavior of turbomachines, in particular fan or suction devices according to the preamble of claim 1 and a fan or suction device according to the preamble of claim 8.

Turbomachines known from the prior art, in particular blowers or suction devices, have individual flow regions which are too

Vortex formation, flow losses and noise lead. These effects occur in particular in the flow areas in which the flow separates from a surface and / or turbulent flows arise. In the following, such flow areas are referred to as "faulty" flow areas.

A blower device may for example be formed as a centrifugal fan device, which comprises a drum rotor with a plurality of blades, wherein the blades are arranged concentrically to the axis of rotation of the drum rotor and thereby form, for example, a circular cylindrical envelope. The structure and operation of such a drum rotor are well known, for example, from the document DE1 16231.

In such a drum rotor, in particular, the air is sucked in axially and tangentially removed via blades, and tapped over a so-called Abgriffslippe from the drum rotor. A drum runner has a big one in particular

Ablösegebiet in the axial inflow, so that about 30% of the blade depth of the drum rotor are not completely flowed through. Also in the field of

Abgriffslippe it comes to separation phenomena and due to the tapping lip due to the deflection of the flow to a noise.

CORRECTIVE VERSION Already in the document DE1 081 181 and the document US 5,169,290 approaches are described to provide in a portion of the blade surface targeted roughness, so as to produce small flow vortices to improve the detachment behavior of the drum rotor.

Such directed turbulence of the flow is applied to gliders by means of a serrated band in the area of possible detachment blowing and before rowing.Figures with large pitch changes can be found especially in humpback whales, which swim tight curves in the hunt, as well as owls, the night hunters fly slowly and quietly, have one of the humpback whale fin

corresponding, structured, in this case, a toothed wing leading edge.

The polar of a profile are comparable with and without hump. The humps cause higher glide numbers at higher angles of attack, or allow higher

Angle of attack as the same profile with smooth surface. This advantage may be paid with slightly worse glide numbers in other areas of the polar. For example, in the documents US 6,431, 498 and US 2006/0060721 the use of such profiles for aircraft wings is described. Bruno Kerschgens also has "similar-chain-theoretical adaptation of a humpback whale profile for use in compressible media and subsequent studies

Computational Analysis of the Resulting Geometry Using CFD "at RWTH Aachen University in 2007 numerically examines a humpback whale profile and describes a general application in turbomachinery D. Custodio has in his master thesis" The Effect of Humpback Whale-like Leading Edge Protuberances on Hydrofoil

Performance "at the Worcester Polytechnic Institute in 2007

Humpback whale profile investigated experimentally.

A profile like the paraglider, with similar characteristics as the Buckewal profile, describe Zverkow, ID and Zanin, B.Yu, in 2003 in the publication "Wing Form Effects on Flow Separation", pp. 197-204, Vol. Issue 2, Thermophysics Zverkov and Zanin have come to the conclusion that undulating profiles can be advantageous especially in oblique, turbulent and transient directions. In addition, such profiles have a better hysteresis behavior. This means that a detached flow comes back to concern faster.

The operation of a structured surface is based on the structuring of the flow in longitudinal vortices, in that the velocity in the boundary layer is also made uneven by the irregularities of the surfaces.

These vortices act as a kind of linear boundary layer suction. In the valleys, weak separate separation bubbles occur which are controlled and stabilized by the longitudinal vortices (see, for example, Fig. 5, Zverkov et al., 2003).

Improvements to the tips of a transonic axial compressor of a

Aircraft engine by means of notches is described for example in the document EP 2 050 929. For the development of a drive for a glider, in particular the document DE 10 2007 055 507 is a so-called

To remove tilted lips procedure. A special push fan is used in the

Publication DE 103 00 621 described. The oblique lip, ie the inclined tapping lip, of a drum rotor is, according to the document DE 10 2007 055 507, executed as a half tine (see Fig. 2a, b) or as a whole tine (see Fig. 14). This is, so to speak, the limiting case of a serrated or wavy tapping lip, where there is only one point.

Also, from the publications DE 199 1 1 850, PCT / DE00 / 04439 and DE

102007039635 already known suction devices that work by blowing over surfaces.

Based on this, it is an object of the invention, the flow behavior of

Turbomachines, in particular blower or suction to improve. The object is achieved on the basis of the features of the preamble of claim 1 and 8 respectively by their characterizing features.

An essential idea which is the basis of the invention is that, at least in those surface regions of the turbomachine in which the flow is detached from the surface and / or turbulent flows occur, longitudinal swirls are generated by means of a structured surface section, via which the flow is structured. By means of the structured with longitudinal vortex flow, the flow of turbulent flows through or over surface areas of

Turbomachines are significantly improved, in particular a significant improvement in the flow at the tap and / or the blades of a fan or suction, are achieved at the Ausblaskante a suction device or an airfoil. By the directional adaptation according to the invention and / or

Direction specification of structuring, the "disturbed" over-, um- or

flowed through areas of a fan or suction device are designed such that an improvement in the flow for the intended purposes, so that adjusts an improvement in efficiency. The inventor has also recognized that preferably in fluidically disturbed areas a

Structuring of the surface Fluidic advantages, whereas areas with steady flow continue with a smooth or only a little

structured surface should be provided. The dimensioning of the structured surface area is among others of the respective

fluidic requirements dependent.

In an advantageous development of the invention, at least two flows having different ones are formed by a structured surface section

Flow rates generated, namely an overflow and / or underflow.

The tapping lip of a blower and suction device with a drum rotor is further advantageously provided with a structured surface portion, which, for example, designed as a kind of serrations, wavy line or hump arrangement is. This advantageously achieves a reduction of the noise and generation of longitudinal vortices, by way of which the flow in the region of the tapping lip can be stabilized.

In a further advantageous embodiment, the blades of the drum rotor at least partially jagged, wavy or bumpy or structured comparable formed by means of roughness, bumps or beadings. As a result, the flow behavior is particularly in the disturbed, unsteady

Flow areas of the blower or suction device and at high

Angle of attack significantly improved. For example, at the blade edge in the region of the inlet, in particular at high blades as a drum rotor. In undisturbed, stationary flow areas, on the other hand, a smooth, ie unstructured or only very slightly structured surface is advantageously used. The

Structuring at the entrance may be used instead of or in combination with the usual

Measures to improve the flow in the inlet area, ie with a

Torsion, inclination, V-position or sweep of the blades are applied.

Advantageously, the structuring is oriented in the direction of the flow direction and / or designed to guide the flow in a predetermined flow direction. The concrete execution of the structuring can be determined and implemented by means of sine functions, Fourier and other series developments, splines, etc. It can also be a structuring using freehand lines.

In blower or suction device, an increase in the detection effect is possible when using the method according to the invention. With blower or

Suction device by means of blow-out, it is necessary to make the confining flow stable and to steer towards the suction surfaces. With blower or

Extracting device in "Coanda technique", the blowing takes place, for example via a Coanda tube, whereby a structuring of the tube is carried out for this purpose Increase the entrainment of the pollutant flow In extreme cases, the structuring of the surface runs from the exhaust opening to the exhaust opening.

The suction at the trailing edge of a corrugated wing can be an improved method of boundary layer extraction. In this case, preferably in valleys, so in areas where the longitudinal vortices rotate away from the surface, sucked.

The invention will be described below with reference to an embodiment in

Connection with figures will be explained in more detail. In addition, arise

Further developments, advantages and applications of the invention also from the following description of the embodiment and from the figures. In this case, all described and / or illustrated features alone or in any combination in principle subject of the invention, regardless of their

Summary in the claims or their dependency. Also, the content of the claims is made an integral part of the description.

It is expressly understood, however, that the invention should by no means be restricted to the example given. The figures show:

Fig. 1 by way of example a plan view of an inventively structured

Surface section;

2 shows by way of example a section through the structured surface section according to FIG. 1;

3 shows an example of several side views of the blades of a turbomachine;

By way of example, FIG. 4 shows a section through the axis of rotation of the impeller of FIG

Drum runner;

5 shows an example of a cross section through the spiral housing of a

Drum rotor;

6 shows by way of example a side view of the spiral housing according to FIG. 5; 7 shows, by way of example, the cross-sectional profile of a tapping lip with a structured surface section;

8 shows an example of a detail of the spiral housing in a sectional view;

9 shows by way of example a spatial representation of a structured spiral tap;

Fig. 10 by way of example perspective views differently structured

Surface portions;

Fig. 1 1 by way of example a combination of differently structured

Surface portions;

Fig. 12 by way of example a perspective view of a wing with structured

Surface;

Fig. 13 by way of example a corrugated airfoil

FIG. 14 shows, by way of example, a drum rotor with blades with at least partially curved surface slants; FIG.

Fig. 15 shows an example of a side view of the spiral housing without drum rotor;

Fig. 1 6 shows an example of a side view of the centrally cut spiral housing without drum rotor;

Fig. 1 by way of example a perspective view of the cut

Spiral housing without drum runner from the outlet side;

Fig. 18 example aft an oblique view of the spiral housing;

19 shows by way of example a perspective view of the teeth;

20 shows an example of a section through a suction device and

21 shows by way of example a perspective view of the suction device according to FIG

20th

FIG. 1 shows, by way of example, a surface section 10 of a perspective view structured according to the invention. The structured surface portion 10 forms a plurality of projections 20 on a leading edge 30. The profile of the structured δ

Surface portion 10 is preferably carried out wavy and is in valleys 50th

(dashed lines) and ridges 40 (solid lines) divided. The leading edge 30 extends, for example, perpendicular to the mean flow direction of the flow 60 or closes with this an obtuse angle.

At an approximately uniform flow 60 of the structured

Surface section 10 causes a faster flow 70 in the valleys 50 and a slower flow 80 in the region of the ridges 40, i. At least two flows 70, 80 are generated at different flow rates. Here, the valleys 50 and burrs 40 of the structured run

Surface portion 10 approximately parallel to each other and preferably approximately along the mean flow direction of the flow 60th

In the present embodiment, the flow 70 is leading in the valleys 50, whereas the flow 80 remains on the ridges 40. Thus, the faster flow 70 tears the surrounding slower flow 80 with it, creating longitudinal vortices 90. The resulting longitudinal vortices 90 can be taken in particular from the sectional view along the line A-A.

FIG. 2 shows the cut surface 120 through the structured surface section 10. The cut surface 120 runs approximately perpendicular to the flow 60. The designation 1 10 designates the wavy line that arises when the structured surface section 10 intersects the cut surface 120.

FIG. 3 shows the blades of an example single-flow turbomachine, for example the blades of a drum rotor. The flow takes place

for example, from the left. The end 190 of the blade oriented toward the suction opening is at the top. These blades can look like profile 210, semi-circular profile

Plastic 220 or 230 made of sheet metal, supervision. Denoted by 240 is a section through the unstructured part of the sheet metal blade. The valleys of

Structuring are shown as dashed lines 40 and the ridges as solid lines 50. In the blades 270 and 280, the gradients of the structuring 100, 105, 205 also bent. The curves 105, 205 also change along the blade depth. For the blades 260, 290, 300, the structuring 200 is rectilinear. In the blades 260, 290, the distances between the

Change structuring. Blade 300 is intended to represent constant or almost constant distances between the structuring, ie periodic or almost periodic structuring.

Frequently, such blades are made by drum runners from a sheet material, in particular stamped. Such a blade made of sheet metal with relatively narrow valleys 40 is designated by the symbol 300. The front and / or rear edge is, for example, jagged 310 and / or straight 320 formed. This applies to both the unstructured surface portion and the structured surface portion of the blades of the drum rotor.

In Figure 4, the flow conditions in the flow through the impeller 180 of a drum rotor are shown in a Schnittdarstetlung example. Shown is an axis-parallel section through the center line 160 of the drum rotor. Through the inflow ring 1 70, the flow 150 flows through the blades 1 30, 140. The one blade 130 has, for example straight edges and a straight structuring 200, whereas another blade 140 has a wavy inflow edge and an oblique, curved, i. does not have rectilinear structuring 205. Furthermore, the blade 1 30 is completely structured. It can also be seen in particular from FIG. 4 that a plurality of blades 130, 140 with different structuring can be used in an impeller of a drum rotor.

Figure 5 shows the spiral housing of a drum rotor 330 from the suction port of the impeller 340 ago. The spiral housing is cut centrally, along the line BB. By way of example, only three blades 350 of the impeller 340 are shown, which are located opposite the tapping lip 360. Behind the tap lip 360, the housing channel widens as a jump diffuser 370 toward the outlet opening 380. By means of the dashed line 440 of the wall profile at a hollowed hump 450, indicated. This is explained in more detail in the description passage relating to FIG.

FIG. 6 shows a plan view of the outlet cross section 380. Here, the tapping lip is realized in the form of a spiral lip 410. The course of the spiral lip 410 is wavy or serrated. The symbol 390 designates the center line of the spiral housing 330. In the prior art, the spiral lip 410 extends as a slightly bent line 405. For clarity, the line 405 is drawn above the line 410. The structuring is in the present embodiment, a wavy version 410 with valleys 50 and ridges 40th

An irregular profile 420 of a tapping lip is shown in FIG. 7, which shows

in particular also asymmetrical to the center line 390 is formed. For comparison, the bend-shaped course 405 of known spiral lips 410 is shown below the course 420.

Figure 8 shows a section 480 of the spiral housing 330 in the region of the tap, in two variants. On the one hand in the realization of the tap in the form of a conventional tap lip 360 and when using a spiral lip 360. First, a section through a tooth-shaped projection 450 of the spiral lip 360 is shown, such as a section along the line BB of Figure 6. In the normal case, the wall course 435 not hollowed out to the wall in the jump diffuser 500 out. In oblique lip case, the wall course 440 is hollowed out to the course of the wall in the jump diffuser 500. The profiling 460 creates a round transition between

In other words, the wall course 440, 445 is also structured in the wall area behind the spiral lip 360 to the inlet 520 from the impeller back. In this case, the hollowed-out hump provided with the code 450 results. FIG. 9 again shows in a spatial representation a structured spiral tapping with a massive projection 510 and a hollow, approximately centrally cut-back projection 5. The tapping divides the inflow space 520 from the outflow space 530. The dotted line 540 is an axis-parallel straight line. At this line, two flow vectors 550, 560 are shown at different axial positions. The flow 550 flows into the outflow 530, the flow 560 in the

Inflow space 520.

A plan on two axial sections is marked 570,580. A massive tap shows the cut 580. This is the normal case described above. It can be a massive spiral tongue or a massive hump. The oblique lip fall, ie a hollow tap, is represented by the cut 570 through a hollowed out hump.

FIG. 10 shows various structuring possibilities on surfaces, middle part

Beading 590, roughness 600 and serrated 610.

FIG. 11 shows that these structuring possibilities can be provided both on the edges 620 and on the surface 630. The structuring on the surface is preferably aligned in the direction of the flow 640

FIG. 12 shows, by way of example, an aerofoil 650 with structuring which is shown in FIG

Root area 660 has roughness changes 670 of the surface near the separation point. These are formed in the middle region of the wing 680 in the vicinity of the trailing edge 690 in the form of waves 700 and in the region of the wing tip 710 a continuous structuring 720 is realized. An influence on the boundary layer within the structured regions can take place via a suction at the trailing edge 690, by suction via hole lines 730, individual holes 735, via slots 740, 745 or via a porous field 750. Likewise, other forms of boundary layer control can be used instead of suction.

Boundary layer control in general, symbolized here as ellipse 470, takes place on preferably in the area of the valleys 50 or in the areas between the roughnesses 55 instead. These smooth regions 55 between the roughnesses could also be referred to as roughness valleys. Slits 745 for boundary layer control by means of suction can run in wing longitudinal direction or perpendicular to the flow 640 near or at the trailing edge 690. The slots 740 can also run parallel to the convergence lines or to the talllines 50, 55. The use of

Structuring makes sense in the root area 660 and in the middle area 680 of a wing, especially in conjunction with boundary layer control.

Figure 1 3 shows a wavy profile in which both the surface 770 and the edges 780 are corrugated. The Grenzschichtabsaugung can be done via a perforated box 790 or 745 740 slots. It is essential that the suction is based on the direction of the ridges 40 and valleys 50, which is the orientation of the longitudinal vortices 760 in FIG

Stimulate direction of flow 640. As a rule, the suction or

Boundary layer influence are located in the valleys. However, there may also be cases where an arrangement of boundary layer control agents, e.g. the slots 745, 740, makes sense in the burrs.

Figure 14 shows as an example of construction the impeller of a drum rotor 810 with sections of corrugated blades 820. In particular, the blades 820 are corrugated in the outlet opening of a spiral housing and the corrugation extends approximately over at least one third of the width of the blades 820.

Figure 1 5 shows a side view of the volute casing 840 of a drum rotor. The outlet side is marked 870. The region of the tap is denoted by the symbol 830.

FIG. 16 shows a plan view of the centrally cut-open housing according to FIG. 1. Only the serrated region of the tapping lip, ie the row of serrations 850, are shown in full width for clarity. Figure 1 7 shows the volute casing 840 as a view of the Ausblasseite 870. The abbreviation 850 is turn the Serrated series. FIG. 18 shows an oblique view of the spiral housing 840 and the row of teeth 850.

In Figure 19, the prongs are shown separated from the Cehäuseinneren in a perspective view. It will be appreciated that the serrations 860 are hollowed out, i. between the teeth walls 880, the cavity 890 is located.

FIG. 20 shows a section of a suction device, which is supported by means of blow-out 900 above a surface 910. The outflow slot 920 is connected to a pressure chamber 930. 940 designates the suction or filter surface and 950 the

Aspiration.

In Figure 21, this suction device is shown in a perspective view, wherein in the left half of the drawing, the embodiment according to the prior art is shown. The right half of the drawing shows a structured, wavy one

Outflow surface 915. In this case, the outflow slot 920, also have a wavy structuring 925 or holes 960 by Ausström be replaced.

The invention has been described above by means of an embodiment. It is understood that numerous modifications and variations of the invention are possible without departing from the inventive concept.

List of reference structured surface

humpback

At flow edge

Bone

Valleys

Areas between the roughnesses

uniform flow

faster flow

slower flow

longitudinal vortices

curved structuring course

variable curved structuring course

wavy line

cutting plane

shovel

Flow through blades

center line

Einströmring

Wheel

End of the Schaufei to the intake port

Structuring gradients straight

Structuring patterns not straightforward

profile

Semicircular profile made of plastic

Semicircular profile made of sheet metal

Blechschaufei

Supervision of the direction of flow

shovel shovel

shovel

Shovel with periodic or almost periodic structuring ragged edge

Straight edge

volute

Intake opening Impeller

shovel

Abgriffslippe

jump diffuser

outlet opening

center line

Wall beam

Course of the spiral lip as a bent line

wavy course of Spirailippe

irregular, asymmetrical course of the spiral lip wall course, hump not hollowed out

Wall path, hump hollowed out

humpback

profiling

Boundary layer control

neckline

Wandlverlauf in jump diffuser

structured tap, massive hump

structured tap, hollow hump

inflow

outflow

Line paraxial

Flow vector in outflow space Flow vector in inflow space

Cut normal spiral or massive hump

Cut hollowed out hump

Surface with beadings

Surface with roughness change

Surface with teeth

Structuring on edges

Structuring on surface

inflow

Wing with structuring

root area

Rauhigkeitsänderungen

middle area of the wing

trailing edge

waves

Surface with teeth

Structuring on edges

hole lines

individual holes

slots

porous field

longitudinal vortices

surface

edge

Lochfeld

waves

Impeller design example

corrugated blades

Area of the tap

volute pink series

Pink

air outlet

pink walls

cavity

Blow out

surface

wavy surface

Outflow slot wavy outflow slot

pressure chamber

Suction or filter surface

aspiration

outflow holes

Claims

claims

Method for influencing the flow behavior of turbomachines, in particular fan or suction devices, wherein the turbomachine has a flow-guiding surface with at least one structured surface section (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 515), characterized in that at least in the

Surface areas of the turbomachine, in which the flow is detached from the surface and / or turbulent flows occur, by means of a structured surface portion (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 515) longitudinal vortex be generated over which the flow is structured.

A method according to claim 1, characterized in that the structuring (100, 105, 205) of the structured surface portion (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 51 5) along the direction the flow (60) is oriented.

A method according to claim 1 or 2, characterized in that by a structured surface portion (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 51 5) at least two flows with different

Flow rates are generated.

Method according to one of claims 1 to 3, characterized in that in the region of the structured surface portion (10, 200, 205, 250, 260, 270, 280, 290, 300, 360, 510, 51 5) at least partial blowing and / or or sucking off the flow is performed.

5. The method according to any one of claims 1 to 4, characterized in that a wave-like, a plurality of mutually parallel projection or ridges (40) and valleys (50) exhibiting surface portion is generated.

6. The method according to any one of claims 1 to 5, characterized in that a structured surface portion with periodic or irregular

Structuring is generated.

7. The method according to any one of claims 1 to 6, characterized in that

by means of the structured surface section an over- and / or

Undercurrent is generated.

8. blower or suction device comprising at least one housing,

in particular spiral housing (330), with at least one suction opening (340) and at least one outlet opening (380), a drum rotor (180) accommodated rotatably about a rotation axis in the housing (330) and having a plurality of blades (350) and a tapping rib (360) , characterized in that at least in the region of the suction opening (340) and / or in the region of the tapping rib (360) at least one structured surface region (410, 460) is provided for generating longitudinal vortices.

9. Blower or suction device according to claim 8, characterized in that at least the suction opening (340) facing surface portions of the blades (350) of the drum rotor (180) are structured.

10. Blower or suction device according to claim 8 or 9, characterized

in that at least one of the blades (350) of the drum rotor (1 80) facing surface portion of the Abgrifflippe (360) is structured.

1 1. Blower or suction device according to one of claims 8 to 10, characterized in that the structured surface portions (410, 460) through Shafts (40, 50), bosses (20), serrations (610), flanges (590), changing roughness changes (600), variable burrs and / or edges are formed.

12. Blower or suction device according to one of claims 8 to 1 1, characterized in that the structuring has a periodic course (300) or irregular course (420).

13. Blower or suction device according to one of claims 8 to 12, characterized in that the course of structuring results from a superposition of periodic and irregular progressions.

14. Blower or suction device according to one of claims 8 to 1 3, characterized in that the structuring (100, 105, 205) is oriented in the direction of flow and / or that for guiding the flow in a predetermined flow direction {91 5 , 770) is formed.

1 5. extractor device with a blower or suction device according to one of claims 8 to 14.