DE102010023017A1 - Humpback whale blower, method for locally improving the flow in turbomachinery and vehicles - Google Patents

Abstract

Process for structuring and improving the flow on and through machines and apparatus, in particular blowers, z. As drum rotor, profiles, wings with boundary layer suction and suction. The improvement relates to device properties such as efficiency, noise, glide ratio, operating range, detection effect, etc. As an embodiment, a drum rotor with hump-like tapping lip (extension of the oblique lip process) and with buckelnartig structured blades in the loaded inflow area proposed; the humpback whale blower.

Description

1. State of the art

In many turbomachines flow areas occur, which lead to vortex formation, flow losses and noise. This is especially the case when the flow separates from a surface. I would like to call these areas of the flow disturbed.

A typical example is the drum runner, DE-116231 , This has a large detachment area in the area of the inflow, Roth 1981, so that about 30% of the blade are not properly flowed through.

Also in the area of the tapping lip it comes to detachment and because of the sudden deflection to noise.

Already DE 1081181 and US 5,169,290 By targeted roughness and formation of small vortices try to improve the detachment behavior of the drum rotor better.

The targeted turbulence of the flow is used in gliders using spiked band in the area of possible detachment bubbles and before rowing. Flows with large pitch changes can be found particularly in humpback whales swimming close in the hunt, Fish and Lauder, 2006.

But even owls, which fly slowly and quietly as night fighters, have one of the humpback whale corresponding, so a structured, in this case, a toothed wing leading edge.

One can compare the polar of a profile with and without humps. The humps cause higher glide numbers at higher angles of attack, or allow higher angles of attack than the same profile with a smooth surface. This advantage may be paid with slightly worse glide numbers in other areas of the polar. US 6,431,498 and US 2006/0060721 (Watts and Fish), describe the use of such profiles for use in an apparatus. Kerschgens, 2007, numerically examines a humpback whale profile and sees a general application in turbomachinery. Custodio, 2007, investigates a humpback whale profile experimentally.

A profile similar to the paraglider, with similar characteristics as the buckewal profile, describe Ilya Zverkov et. al. in RU 2 294 300 ., see also Zverkov, Zanin, 2003. Zverkov and Zanin describe that wavy profiles can bring advantages especially with oblique, turbulent and unsteady flow.

In addition, such profiles have a better hysteresis behavior. This means that a detached flow rests faster again.

The operation of the structured profiles or surfaces is based on the structuring of the flow in longitudinal swirls, in that the velocity in the boundary layer is also made uneven due to the irregularities of the surfaces. These vortices act as a kind of linear boundary layer suction. In the valleys, weak separation bubbles separate from each other (through the hills), controlled and stabilized by the longitudinal vortices, cf. 5 , Zverkov et. al. Of 2003.

Improvement at the tips of a transonic axial compressor (aircraft engines) by means of notches describes EP 2 050 929 ,

For the development of a propulsion for a glider, I developed the oblique lip method, DE 10 2007 055 507 , as well as the push fan DE 103 00 621 , The oblique lip, so the inclined tapping lip in a drum rotor is in DE 10 2007 055 507 as a half tine, , b, or as a whole tine, , executed. This is, so to speak, the limiting case of a serrated or wavy tapping lip, where there is only one point.

There are also suction devices which operate by blowing over surfaces. This will include in DE 199 11 850 . PCT / DE 00/04439 and in DE 10 2007 039 635 described.

2. invention

• a) die Verbesserung der Strömung am Abgriff eines Gebläses
• b) an den Schaufeln eines Gebläses und
• c) bei der Anwendung der Grenzschichtabsaugung an einem Tragflügel
• d) ein allgemeines Verfahren und Maßnahmen die Strömung an turbulent durch- oder überströmten Bereichen von Maschinen oder Geräten günstiger zu gestalten.

The invention describes as application of the structured with longitudinal vortices flow,

• a) the improvement of the flow at the tap of a blower
• b) on the blades of a fan and
• c) in the application of the boundary layer suction on a wing
• d) a general method and measures to make the flow of turbulent through-flow or overflow areas of machinery or equipment cheaper.

These measures make sense only where the flow is actually disturbed. The areas that are "right", ie stationary and flowed through from the right direction should be provided with a smooth or slightly textured surface.

How big these areas are or where they are depends on the requirements of the operating areas.

You can the tapping lip of a fan, z. B. drum runners, in extension of DE 10 2007 055 507 as a kind of Zackenreihe, wavy line or hump arrangement run. The advantages are a reduction of the noise and generation of longitudinal vortices that stabilize the flow in the region of the tapping lip.

Furthermore, you can make the blades of a fan jagged, wavy or bumpy or comparable structured by means of roughness, bumps or Umbördelungen so that the behavior is significantly improved at disturbed, unsteady flow conditions and high angles of attack.

This is at the blade edge in the region of the entry of the case, especially at high blades as the drum rotor, cf. Roth 1981. In undisturbed places, a smooth, that is unstructured, or only slightly structured profile should be used. The structuring at the inlet can be used instead of or in conjunction with the usual measures to improve the flow in the inlet area, so with a twist, inclination, V-position or sweep of the blades.

The flow is also disturbed towards the trailing edge of airfoils. The structured profile is inferior to the same profile in a smooth design usually, ie at low angles of attack and stationary flow. However, in the area of the trailing edge, the flow can be optimized by generating longitudinal vortices for state-of-the-art boundary layer control methods (eg, boundary layer exhaust, blow-out, synthetic jets, etc.). The flow is directed to where it can be influenced. These are in particular the convergence and divergence zones of the longitudinal vortices on the surface. This boundary layer influencing thus takes place especially for the stabilization of the small-scale detachment areas. The application of the boundary layer influencing is therefore localized smaller than before (smooth wing) and thus significantly simplified.

In the case of suction, these may be rows of holes, slots, porous areas or other permeable openings in the region of these detachment areas. In the case of wavy profiles, these are preferably the valleys.

The structuring can be oriented in the direction of flow, or oriented as the flow should run. (Valley effect of meteorology: wind on the ground blows preferably parallel to the valley)

The aim of the invention is, by means of the directional adaptation and / or directional specification of the structuring, to design the disturbed, circulated or flow-through areas of turbomachines, aircraft or watercraft in such a way that the flow is improved for the intended purposes.

It may well be the case that you have the power z. B. intentionally reduce a wing, such as landing flap.

In general, however, it will go to improve the efficiency.

In particular, the purpose of suction devices is to increase the detection effect. In the case of suction devices by means of blowing, it is important to make the limiting flow stable and direct it towards the suction surfaces. The blowing, z. B. over a Coanda tube, can be improved by means of a structuring of the tube, whereby the flow can be selectively applied longitudinal vortex. These longitudinal vortices also increase entrainment of the pollutant flow. In extreme cases, the structuring of the surface runs from the exhaust opening to the suction opening.

The structuring can be carried out by means of sine functions, Fourier and other series developments, splines, etc. It can also be a structuring using freehand lines.

Dimensioning examples of structuring, z. As the waves or humps, you can see the state of the art, see sources.

In the following the invention will be explained by means of drawings. Hand sketches are intentionally used to give the "hunchback" principle of the invention also drawing. It should also be expressed that edges can be both straight and irregular.

3. Pictures

shows a structured surface 10 perspective. It is an area with humps 20 at the leading edge 30 , The profile is also wavy and is in valleys 50 (dashed lines) and burrs 40 (solid lines) divided. The uniform flow 60 will flow along the profile in a faster flow 70 and a slower flow 80 split. The flow 70 in the valleys 50 rushes forward. The flow 80 on the ridges 40 stay behind The faster flow 70 tears the surrounding slower flow 80 with itself, causing longitudinal swirls 90 arise. These are shown in a section AA.

shows the cut surface 120 through the structured area 10 , The cut surface 120 is arranged approximately perpendicular to the flow. 110 is the Wavy line through the cut of the surface 10 with the cut surface 120 ,

shows the blades of a turbomachine (single-flow). In this case, it's the blades of a drum-runner. The flow is from the left. The end oriented towards the suction opening 190 the bucket is up. These blades can as a profile 210 , Semicircular profile made of plastic 220 or made of sheet metal 230 be executed, supervision. 240 shows a section through the unstructured part of the sheet metal blade.

The valleys of the structuring are shown as dashed lines 40 , the ridges as solid lines 50 shown.

Lateral supervision: By the blades 270 and 280 are the gradients of structuring 100 . 105 . 205 also bent. The courses 105 . 205 also change along the blade depth. With the blades 260 . 290 . 300 the structuring proceeds 200 straight. With the blades 260 . 290 are the distances between the structuring change. shovel 300 should represent constant or almost constant distances between the structuring, ie periodic or almost periodic structuring.

Shovels are often stamped out of sheet metal by drummers. Such a shovel with relatively narrow valleys 40 should 300 represent. The front and / or rear edge can be jagged 310 and / or straight 320 be. This applies both to the unstructured surface area and to the structured surface area.

shows the conditions when flowing through the impeller 180 , Shown is an axis-parallel section through the center line 160 , About the Eimnströmring 170 the current flows 150 through the blades 130 . 140 , shovel 130 has straight edges and a straight-line structure 200 on. shovel 140 has a wavy inflow edge and an oblique, curved or not rectilinear structuring 205 on. Furthermore, there is a shovel 150 structured everywhere. The should also show that shovels in an impeller 130 . 140 different structuring can be used.

shows the spiral casing of a drum rotor 330 from the suction opening of the impeller 340 ago. It is cut open in the middle, section BB. There are only 3 blades 350 of the impeller shown. these are opposite the tapping lip 360 , Behind the tap lip, the channel expands as a jump diffuser 370 on the outlet section 380 ,

The dashed line 440 is the course of the wall in a hollowed out hump 450 . , This will be in explained in more detail.

In the this is as a view of the outlet cross-section 380 shown. The course of the spiral lip 410 is wavy or serrated. 390 is the centerline of the volute casing 330 , In the prior art, the spiral lip runs as a slightly bent line 405 , Because of the clarity, the line is 405 above the line 410 drawn. The structuring in this example is a wavy design 410 with valleys 50 and ridges 40 ,

An irregular course 420 a tapping lip shows , This course is also asymmetrical to the midline 390 , For comparison is again the bent curve 405 the previous spiral lips shown.

shows the section 480 of the volute casing 330 also in two variants of the course of the wall behind the spiral lip 360 ,

It is a section through a tooth-shaped hump 450 the spiral lip 360 shown, about section BB in ,

Normally:

In the course of the wall 435 is the hump not to the wall in the jump diffuser 500 hollowed out.

Bevel lip Fahl:

In the course of the wall 440 is the hump to the wall in the jump diffuser 500 hollowed out. The profiling 460 creates a round transition between inflow space 520 and outflow space 530 from the spiral housing 330 ,

In other words - the course of the wall 440 . 445 is also in the wall area behind the spiral lip 360 to the inflow space 520 structured out of the impeller - in this case, the hollowed hump like 450 ,

shows again in a spatial representation of a structured spiral tap with a massive hump 510 and a hollow, roughly centered hump 515 , The tap divides the inflow space 520 from the outflow space 530 , The dashed line 540 is an axis-parallel straight line. At this line are two flow vectors 550 . 560 shown at different axial positions. The flow 550 flows into the outflow chamber 530 , the flow 560 in the inflow space 520 ,

A view of two sections on the axis, 570 . 580 , A massive tap shows cut 580 , This is the normal case described above. It can be a massive spiral tongue or a massive hump.

The oblique lip case, so a hollow tap, is by the cut through a hollowed hump 570 shown.

shows different structuring possibilities on surfaces, by means of beadings 590 , Roughness 600 and spikes 610 ,

shows that these structuring options both at the edges 620 as well as on the surface 630 be provided. This structuring on the surface should be approximately in the direction of the flow 640 be aligned.

shows a wing 650 with structuring. These are in the root area 660 Rauhigkeitsänderungen 670 the surface near the separation point.

These are in the middle area of the grand piano 680 near the trailing edge 690 waves 700 , in the area of the wing tip 710 a continuous structuring 720 ,

An influencing of the boundary layer within the structured areas can take place via a suction at the trailing edge 690 , by extraction via perforated lines 730 , single holes 735 , via slots 740 . 745 or over a porous field 750 respectively. Likewise, other forms of boundary layer control can be used instead of suction.

Boundary layer control in general, here as an ellipse 470 symbolizes, finds best in the area of the valleys 50 or in the areas between the roughnesses 55 instead of. These smoother areas 55 between the roughnesses one could also call roughness valleys.

slots 745 for boundary layer control by means of suction can in wing longitudinal direction or perpendicular to the flow 640 near or at the trailing edge 690 run. The slots 740 can also be parallel to the convergence lines or to the valley lines 50 . 55 run.

The use of structuring makes in the root area 660 and in the middle area 680 of a wing sense in conjunction with boundary layer control.

Because the straight wing is superior to the structured wing usually with homogeneous flow. At the surface tip, structuring over the tread depth without boundary layer extraction makes sense for aircraft that are not allowed to stall at the surface tips. These are in particular flying wings with an S-beating profile, in which the buffeting distribution leads to strong performance losses.

It is thus possible to use the change in the structuring along the edge of the blade instead of a reduction.

shows a wavy profile, where both the surface 770 as well as the edges 780 are wavy. The Grenzschichtabsaugung can over a hole field 790 or slots 745 . 740 respectively. It is essential that the suction is in the direction of the burrs 40 and valleys 50 oriented, which is the orientation of the longitudinal swirls 760 in the direction of the flow 640 stimulate. As a rule, the extraction or boundary layer influence should be in the valleys. But there may also be cases where an arrangement of the means for influencing the boundary layer, z. B. the slots 745 . 740 , in the field of burrs makes sense.

shows as a construction example, the impeller of a drum rotor 810 with wavy blades 820 ,

shows a side view of the spiral housing 840 a drum-runner. The outlet side is 870 , The area of the tap is 830

shows a plan view of the centrally cut housing of , Only the serrated area of the tapping lip, the row of teeth 850 , has been shown in full width for clarity.

shows the case 840 as a view from the exhaust side 870 , 850 is again the row of teeth.

shows an oblique view of the housing 840 and the row of teeth 850 ,

shows the prongs from the inside of the housing. You realize that the spikes 860 are hollowed out. Between the teeth walls 880 is the cavity 890 ,

shows a suction device in section, by means of blow-out 900 over a surface 910 is supported. The outflow slot 920 is with a pressure room 930 connected. This designates 940 the suction or filter surface and 950 the suction flow.

shows this suction device in perspective, on the left of the prior art, so to speak 2-dimensional extruded - is shown. On the right side is a structured, wavy discharge surface 915 shown. In this case, the outflow slot 920 , also wavy 925 or through outflow holes 960 , be replaced.

Based on - It should also be shown that, in the context of this application, the term flow can include overflow or flow around a structured surface, but also inflow into the surface or outflow from the surface.

4. Literature

• Custodio, D., 2007, The Effect of Humpback Whale-like Leading Edge Protuberances at Hydrofoil Performance, Master Thesis, Worcester Polytechnic Institute http://www.wpi.edu/Pubs/ETD/Available/etd-121307-115034/unrestricted /dcustodio.pdf
• Fish, F.E., Lauder G.V., 2006, Passive and Active Flow Control by Swimming Fishes and Mammals, Ann. Rev. Fluid Mech., 38, 193-224 http://darwin.wcupa.edu/~biology/fish/pubs/pdf/2006AnnalRevFluidMech.pdf
• Kerschgens, Bruno, 2007 (?), Similarity Theoretic Adaptation of a Humpback Whale Fin Profile for Use in Compressible Media and Subsequent Examination of the Resulting Geometry Using CFD, Student Thesis, RWTH Aachen University http://pectoralfin.org/Docs/SA_Bruno.pdf
• Roth, H.W., 1981, Optimization of drum rotor fans, fluid mechanics and fluid flow machines 29, pp. 1-45, Verlag G. Braun, Karlsruhe
• Zverkow, I.D., Zanin, B.Yu, 2003, Wing Form Effects on Flow Separation, pp. 197-204, Vol. 10, No. 2, Thermophysics and Aeromechanics, Novorsibirsk

LIST OF REFERENCE NUMBERS

10

structured surface

20

humpback

30

leading edge

40

Bone

50

Valleys

55

Areas between the roughnesses

60

uniform flow

70

faster flow

80

slower flow

90

longitudinal vortices

100

curved structuring course

105

variable curved structuring course

110

wavy line

120

cutting plane

130

shovel

140

shovel

150

Flow through blades

160

center line

170

Einströmring

180

Wheel

190

End of the blade towards the intake port

200

Structuring gradients straight

205

Structuring patterns not straightforward

210

profile

220

Semicircular profile made of plastic

230

Semicircular profile made of sheet metal

240

sheet metal shovel

250

Supervision of the direction of flow

260

shovel

270

shovel

280

shovel

290

shovel

300

Blade with periodic or almost periodic structuring

310

ragged edge

320

Straight edge

330

volute

340

Intake opening Impeller

350

shovel

360

Abgriffslippe

370

jump diffuser

380

Outlet cross section

390

center line

400

wall jet

405

Course of the spiral lip as a bent line

410

wavy course of the spiral lip

420

irregular, asymmetrical course of the spiral lip

430

- not applicable

435

Wall course, hump not hollowed out

440

Wall path, hump hollowed out

445

Wall path, hump hollowed out

450

humpback

460

profiling

470

Boundary layer control

480

neckline

490

- not applicable

500

Wandlverlauf in jump diffuser

510

structured tap, massive hump

515

structured tap, hollow hump

520

inflow

530

outflow

540

Line paraxial

550

Flow vector in outflow space

560

Flow vector in inflow space

570

Cut normal spiral or massive hump

580

Cut hollowed out hump

590

Surface with beadings

600

Surface with roughness change

610

Surface with teeth

620

Structuring on edges

630

Structuring on surface

640

inflow

650

Wing with structuring

660

root area

670

Rauhigkeitsänderungen

680

middle area of the wing

690

trailing edge

700

waves

710

Surface with teeth

720

Structuring on edges

730

hole lines

735

individual holes

740

slots

745

slots

750

porous field

760

longitudinal vortices

770

surface

780

edge

790

Lochfeld

800

waves

810

Impeller design example

820

corrugated blades

830

Area of the tap

840

volute

850

pink series

860

Pink

870

air outlet

880

pink walls

890

cavity

900

Blow out

910

surface

915

wavy surface

920

exhaust slot

925

wavy outflow slot

930

pressure chamber

940

Suction or filter surface

950

aspiration

960

outflow holes

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 116231 [0002]
• DE 1081181 [0004]
• US 5169290 [0004]
• US 6431498 [0007]
• US 2006/0060721 [0007]
• RU 2294300 [0008]
• EP 2050929 [0011]
• DE 102007055507 [0012, 0017]
• DE 10300621 [0012]
• DE 19911850 [0013]
• DE 00/04439 [0013]
• DE 102007039635 [0013]

Claims (10)

Method for influencing the flow 70 . 80 . 150 . 550 . 560 . 640 . 900 using structured surfaces 10 . 200 . 205 . 250 . 260 . 270 . 280 . 290 . 300 . 360 . 510 . 515 , characterized in that this structuring is used on the disturbed and / or affected areas. A method according to claim 1, characterized in that these surfaces waves 40 . 50 , Humpback 20 , Pinks 610 , Beading 590 , changing roughness changes 600 , may have variable burrs or edges. A method according to claim 1 and claim 2, characterized in that the change of structuring periodically 300 , irregular 420 or happens from a superposition of periodic and irregular change. A method according to claim 1-claim 3, characterized in that the structuring 100 . 105 . 205 is oriented in the direction of flow and / or that the structuring of the guidance of the flow in a certain direction 915 . 770 serves. A method according to claim 1-claim 4, characterized in that the flow by means of local boundary layer influence 470 and / or blowout 900 and / or suction 950 and / or Grenzschichtabsaugung over the openings 730 . 735 . 740 . 745 750 . 790 can be controlled. Method according to claim 1-claim 5, characterized in that along a line 540 either a) both overflow and underflow 550 . 540 the structured body takes place, or b) only overflow 550 or only undercurrent 540 takes place or c) the flow guides described under a) and b) are combined. Turbomachine, in particular blower, vehicle or suction device, in particular extractor hood, characterized in that the flow is influenced according to the method set forth in claims 1-6. Turbomachine according to claim 7, characterized in that the structuring in the region of the inflow opening 190 located on the blades and / or at the discharge opening 370 . 435 . 445 . 450 located. Turbomachine according to claim 7 and 8, characterized in that it is a radial fan, in particular drum rotor, and that in the case of flow influencing the tapping lip 360 this hollow 570 and / or massive 580 is executed. Airplane or other aircraft or watercraft according to claim 1-6, characterized in that the flow 640 by boundary layer control 470 and / or by Grenzschichtabsaugung over the openings 730 . 735 . 740 . 745 750 . 790 can be influenced and / or the drive fan is also designed according to claim 1-9.

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