CN105781623A - Tie piece structure for reducing turbulent flow losses - Google Patents

Abstract

The invention discloses a tie piece structure for reducing turbulent flow losses. A wedge-shaped groove channel or a rectangular groove channel is formed in the position of an airflow front stagnation point of the tie piece structure in the radial direction of the tie piece structure, wherein the tie piece structure is an annular structure with the cross section being cylindrical or elliptical; the grooving length L of the tie piece structure is equal to 0.05R to 0.15 R, and R is the radius of a tie piece or half of a short axis of an ellipse; the wedge-shaped inclination angle alpha is equal to 0.3 degree, and when alpha is equal to 0 degree, the rectangular groove channel is formed. According to the tie piece structure, by means of grooving of the tie piece, high-energy fluid is injected into a low-energy fluid region at the tail of the tie piece in a synthetic jet flow manner, and therefore the capacity of the tie piece for resisting the adverse pressure gradient is improved, and the tail vortex-shedding inhibition degree is improved; meanwhile, because the groove is formed in the position of the airflow front stagnation point of the tie piece, the tie piece flowing resistance is reduced to a great extent, and the efficiency of turbine blades is effectively improved; and the tie piece structure reduces the additional mass of the blades at the same time so that additional centrifugal force loads can be reduced, and the safe running margin is effectively improved.

Description

A kind of lacing wire structure reducing flow-disturbing loss

Technical field:

The invention belongs to turbomachinery field, be specifically related to a kind of lacing wire structure reducing flow-disturbing loss.

Background technology:

Turbomachinery, is with the fluid flowed continuously as working medium, by the interaction with blade, by fluid Energy is converted into the dynamic power machine of mechanical energy, is the core component in energy power system, national economy with Defence business is all indispensable ingredient.Blade plays vital effect in energy is changed, Therefore its safety the most all receives much concern in whole derived energy chemical field with high efficiency.

Turbine blade by Airflow Exciting-Vibration Force, thus can produce blade vibration at work, and reduce blade and shake Dynamic key measure mainly includes two aspects that (1) considers that frequency avoids rate, it is to avoid produce resonance；(2) use Blade damping structure, such as damping boss, damp-ing wire, damps shroud etc., by Damping work vibrational energy, Thus reduce blade vibration.Wherein use blade damp-ing wire structure, be widely used in reducing shaking of linear leaf Dynamic, Fig. 1 is whole circle blade damp-ing wire structural representation.

Damp-ing wire is different from damping boss and damping shroud structure, and it is present in blade passage structure.Resistance There is adverse pressure gradient near Buddhist nun's lacing wire body structure surface, cause lacing wire surfactant fluid to produce flow separation, and tail The stream field that comes off in whirlpool can produce big disturbance；Damp-ing wire structure leading edge produces flow resistance simultaneously, therefore Inevitably causing extra flow losses, this reduces turbomachinery operational efficiency largely, The most how to reduce turbomachinery flow losses that lacing wire causes always by Chinese scholars extensive concern.It addition, The use of damp-ing wire, particularly with the linear leaf by bigger exciting force, in order to preferably suppression is shaken Dynamic, damp-ing wire size will certainly increase accordingly, not only can affect the stability in flow field, more causes blade attached Add the increase of quality, thus centrifugal load increases the weight of, affect the safe operation of blade.

Summary of the invention:

The deficiency according to existing damp-ing wire of the present invention, it is proposed that a kind of lacing wire structure reducing flow-disturbing loss. While ensureing that existing lacing wire reduces blade vibration effect, improve lacing wire to a great extent and flow about State, coming off of suppression wake's flow field, thus improve the efficiency of turbomachinery；It addition, subtract to a certain extent Little additional blades quality, thus reduce centrifugal load, improve safe operation nargin, there is wide application Prospect.

For achieving the above object, the present invention adopts the following technical scheme that and is achieved:

A kind of lacing wire structure reducing flow-disturbing loss, at the front stationary point of air-flow of lacing wire structure, radially opens Be provided with wedge shape conduit or rectangular duct, wherein lacing wire structure be section be cylindrical or oval loop configuration.

The present invention is further improved by: the slotting length of lacing wire structure is that L=0.05R-0.15R, R are for drawing Muscle radius or the half of ellipse short shaft；The tilt angle alpha of wedge shape conduit=0-3 °, and be rectangle when α=0 ° Conduit.

The present invention is further improved by: lacing wire structure circumference is further opened with oblique fluting, oblique fluting Suction surface grooving angle beta and pressure face grooving angle γ are respectively lacing wire and blade intersecting area vane type line Tangential angle, monolateral channel lengths a=0.2N-0.3N, wherein, N is lacing wire arc length.

The present invention is further improved by: fluting starting point distance molded line beeline b and distance dry friction Face beeline c meets following condition: b >=0.1N, c >=0.1N, described N are lacing wire arc length.

Compared with prior art, it is an advantage of the current invention that:

1, the present invention proposes to slot lacing wire structure, and the mode using synthesizing jet-flow is lacing wire afterbody mental retardation High-energy fluid is injected in fluid mass, thus improves the ability of lacing wire opposing adverse pressure gradient, therefore afterbody vortex shedding quilt Suppression degree improves.

2, slot area is positioned at the front stationary point of lacing wire structure air-flow, and region, front stationary point is flowing maximum resistance region, Therefore the present invention reduces the flow resistance that lacing wire causes to a great extent.

3, fluting radical length is less relative to lacing wire size with circumferential lengths, therefore strong to existing lacing wire structure Degree impact is less；The angle of circumference fluting keeps consistent with regional gas stream angle at this to the full extent, reduces The loss of incidence of conduit fluid, improves flow efficiency.

4, this lacing wire structure reduces blade additional mass, thus reduces additional centrifugal force load, effectively carries High safe operation nargin.

5, when concrete blade design, can be according to practical operation situation, convenient regulation a, b, c, R, L, α, the parameter such as beta, gamma, it is achieved turbomachinery flow efficiency with ensure blade effectiveness in vibration suppression and the optimum of lacing wire intensity Value.

Accompanying drawing illustrates:

Fig. 1 is the turbine blade graphics with whole circle lacing wire；

Fig. 2 is single damp-ing wire blade schematic diagram；

Fig. 3 a is conventional damp-ing wire area schematic；

Fig. 3 b is damp-ing wire area schematic of the present invention；

Fig. 4 is damp-ing wire region of the present invention A-A sectional view；

Fig. 5 is damp-ing wire region of the present invention B-B sectional view.

Detailed description of the invention:

The invention will be further described below in conjunction with the accompanying drawings.

With reference to Fig. 1, shown in Fig. 2, sets forth turn-take damping vane and single only resistance of band damp-ing wire structure Buddhist nun's blade construction.This damping vane includes blade, blade root and damp-ing wire structure.

With reference to Fig. 3 a, shown in Fig. 3 b, sets forth conventional damp-ing wire structure and tie with damp-ing wire of the present invention Structure.The present invention offers wedge shape or rectangular duct on conventional damp-ing wire architecture basics.Primary air passes through lacing wire Streaming flow further downstream, another fraction air-flow passes through lacing wire structure wedge shape or rectangular duct, uses synthesis to penetrate The mode of stream imports in main flow, thus high-energy fluid is injected in the afterbody low energy fluid region for streaming near lacing wire, Therefore the relatively conventional lacing wire of lacing wire tail region pressure increases, thus improves lacing wire opposing adverse pressure gradient Ability, therefore afterbody vortex shedding is suppressed degree and improves.Slot area is positioned at the front stationary point of lacing wire structure air-flow, this Place causes this stationary point air velocity to be 0 due to the reason that lacing wire hinders, and therefore the region near the front stationary point of air-flow is Flowing maximum resistance region, the present invention offers conduit in region, air-flow front stationary point, reduces to a great extent The flow resistance that lacing wire causes.Offer wedge shape or rectangular duct so that additional blades quality reduces simultaneously, from And reduce the additional centrifugal load of blade.

With reference to shown in Fig. 4, give lacing wire structure A-A profile.Lacing wire circumference is oblique fluting, suction Face grooving angle beta and pressure face grooving angle γ are respectively the tangent line of lacing wire and blade intersecting area vane type line Angle.By rational grooving angle, during so that air-flow is by conduit, reduce loss of incidence as far as possible, Thus improve groove internal flow efficiency.Monolateral channel lengths a=0.2N-0.3N, fluting starting point distance molded line Beeline b and distance dry friction face beeline c meet following condition: b >=0.1N, c >=0.1N, wherein N For lacing wire arc length.I.e. while ensureing lacing wire intensity, improve channel flow area the most as far as possible, thus Suppression wake's flow field comes off in a wider context, reduces adverse pressure gradient, improves flow condition.

With reference to shown in Fig. 5, give lacing wire structure B-B profile.The radially slotted position of lacing wire is positioned at lacing wire Region, front stationary point, slotting length is L=0.05R-0.15R, and described R is the half of lacing wire radius or ellipse short shaft； The tilt angle alpha of wedge shape conduit=0-3 °, and be rectangular duct when α=0 °.Limit radially slotted length same Sample is to, while ensureing lacing wire intensity, improve flow efficiency as far as possible；Employing simultaneously can regulate Angle of inclination, this can select suitable included angle according to different actual operating mode, so that inverse Pressure gradient reduces, and effectively controls wake's flow field.

Claims (4)

1. the lacing wire structure reducing flow-disturbing loss, it is characterised in that: the front stationary point of air-flow in lacing wire structure Place, radially offer wedge shape conduit or rectangular duct, wherein lacing wire structure be section be cylindrical or ellipse Circular loop configuration.

A kind of lacing wire structure reducing flow-disturbing loss the most according to claim 1, it is characterised in that: draw The slotting length of muscle structure be L=0.05R-0.15R, R be the half of lacing wire radius or ellipse short shaft；Wedge-shaped slot The tilt angle alpha in road=0-3 °, and be rectangular duct when α=0 °.

A kind of lacing wire structure reducing flow-disturbing loss the most according to claim 1, it is characterised in that: draw Muscle structure circumference is further opened with oblique fluting, the suction surface grooving angle beta of oblique fluting and pressure face angle of rifling Degree γ is respectively the tangential angle of lacing wire and blade intersecting area vane type line, monolateral channel lengths A=0.2N-0.3N, wherein, N is lacing wire arc length.

A kind of lacing wire structure reducing flow-disturbing loss the most according to claim 1, it is characterised in that: open Groove starting point distance molded line beeline b and distance dry friction face beeline c meet following condition: B >=0.1N, c >=0.1N, described N are lacing wire arc length.