CN103670528A - Loading method for turbine blade - Google Patents

Abstract

The present invention provides a kind of loading method of turbine blade, the load character of the two-dimentional blade profile of the turbine blade is controlled by the geometric parameter UGT size of blade profile, and geometric parameter UGT is as follows along the high changing rule of leaf:

, wherein H- blade height, C- root of blade chord length; 1. UGT1 is constant as X ＞ 0.45, between 16 ° ~ 22 °; 2. UGT2 is constant as X ＜ 0.05, between 4 ° ~ 10 °; 3. in the opposite leaf high scope of root of blade region (0, X) and top area (1-X, 1), UGT3-1 is distributed along leaf height with parabola rule as 0.05≤X≤0.45; In the opposite leaf high scope of middle part of blade region (X, 1-X), UGT3-2 is constant, and the value of UGT3-2 is identical as above-mentioned UGT2. The present invention specifies specific situation, the degree of control load and control range of the blade profile load along the high regularity of distribution of leaf, in actual engineering design, is conducive to large-scale application and popularization, strong operability.

Description

The loading method of turbine blade

Technical field

The present invention relates to the design field of turbine blade, be specifically a loading method for turbine blade, the load that mainly refers to vane type line is along the high controlling method distributing of leaf: according to the height H of blade and depth-width ratio (blade height H/ blade chord length C), determine different load location modes.

Background technique

Turbine flow efficiency depends on the aeroperformance of through-flow interior quiet, moving vane to a great extent.Primarily two-dimensional blade profile application process and controlled the flow field of blade passage inside along the high three-dimensional shaping rule of leaf in blade, has also determined the aeroperformance of blade.

For the design of primarily two-dimensional blade profile, it is mainly the profile loss reducing as much as possible in Cascade Flow.(load in leaf grating runner mainly concentrates on the leading edge region of blade to the basic blade profile of front loading, (1) in Fig. 1) and rear loading blade profile (load in leaf grating runner mainly concentrates on the trailing edge region of blade, (2) in Fig. 1) all reaching higher level controlling aspect leaf grating profile loss.But on the whole,, front loading leaf grating, relatively more effectively (loading afterwards the diffusion degree on the more difficult Controlling outline curve back of the body of blade profile arc) than rear loading leaf grating aspect control profile loss, has less profile loss.

For the three-dimensionally shaped design of blade, be mainly that primarily two-dimensional molded line is long-pending folded in blade height direction according to certain torsion rule and crooked rule, thereby realize the effective control to three-dimensional flow field.Reverse the Method for Flow Pattern Design that rule embodies blade, effective control that crooked rule reflection BLADE FORCE stream field intrinsic parameter distributes.

After blade is three-dimensionally shaped, on the intrinsic profile loss basis of the basic blade profile of two dimension, in leaf grating runner, produce complicated ternary and flowed, mainly increased the secondary flow loss of end regions (root of blade leaf high ((3) in Fig. 2) and Ye Gao region, top ((5) in Fig. 2)).At present; for the main method that reduces secondary flow loss, be: after using a kind of height, load basic molded line; by by the load transfer of molded line near trailing edge; postpone the generation of Secondary Flow; effectively control the development of secondary flow in passage, simultaneously according to certain molded line modelling, torsion and crooked rule, realize the three-dimensional modeling of blade; thereby effectively control the flow field in blade passage, reduce flow losses.The main deficiency of this method is that whole blade loads blade profile after leaf height all adopts a kind of height, and for there is no Secondary Flow flow effect or the less high region of blade middle leaf of impact, after still adopting the height of more difficult control profile loss, load blade profile, vane type line load is not controlled along the high distribution of leaf, finally may be caused the flow losses of central region to increase.

In patent CN1982653A, proposed to mix the design method of using fore-loaded airfoil and rear loading blade profile in same blade, after being used, root, the overhead height region of blade load blade profile, at utmost control secondary flow loss, and use fore-loaded airfoil in blade height region, middle part ((4) in Fig. 2), at utmost reduce profile loss.This change blade loading, along the method for the high regularity of distribution of leaf, can utilize the advantage of fore-loaded airfoil and rear loading blade profile simultaneously, further reduces total flow losses.But, say from another point of view, patent CN1982653A has only proposed a kind of macroscopical design concept, the more design method of details is not proposed, as blade profile load along the high regularity of distribution of leaf specifically the degree of what form, control load and control range be how many etc., this operability of applying in actual engineering design is not strong.

Summary of the invention

The object of the invention is to: provide that a kind of more comprehensively, more specifically a kind of blade profile load is along the high location mode of leaf with respect to prior art.

The technical solution adopted in the present invention is:

The loading method of turbine blade, the load character of the two-dimentional blade profile of described turbine blade is controlled by the geometric parameter UGT size of blade profile, and geometric parameter UGT is: adjacent blade profile inner arc exit point is to tangent line on back of the body arc corresponding to adjacent blade profile back of the body arc beeline loca, carry on the back the angle between the tangent line of arc with blade profile back of the body arc exit point place blade profile; Geometric parameter UGT is as follows along the high Changing Pattern of leaf:

, H-blade height wherein, C-root of blade chord length;

1. when X > 0.45, UGT1 is constant, between 16 ° ~ 22 °;

2. when X < 0.05, UGT2 is constant, between 4 ° ~ 10 °;

3. when 0.05≤X≤0.45, in root of blade region, (0, X) and in the high scope of relative leaf of top area (1-X, 1), UGT3-1 distributes with parabola rule along leaf is high;

In the high scope of relative leaf of blade central region (X, 1-X), UGT3-2 is constant, and the value of UGT3-2 is identical with above-mentioned UGT2.

Described UGT3-1 is high as follows with parabola rule distribution mathematical model along leaf:

，0＜h≤X·H

，（1-X）·H＜h≤H

Wherein, h-is apart from the height of root, 0 < h≤H.

The beneficial effect that the present invention produces is:

The present invention is a kind of loading method of turbine blade, according to the height H of blade and depth-width ratio H/C(blade height H/ root of blade chord length C) determine different load distribution methods.In blade, the load character of two-dimentional blade profile is mainly controlled by the geometric parameter UGT size of blade profile, and the geometric parameter UGT that passes through to control two-dimentional blade profile, along the high Changing Pattern of leaf, obtains blade loading along the high distribution rule of leaf.Blade profile load that the present invention is clear and definite, along the concrete situation of the high regularity of distribution of leaf, degree and the control range of control load, in actual engineering design, is beneficial to large-scale application and popularization, strong operability.

Accompanying drawing explanation

Fig. 1 is two-dimentional blading nomenclature schematic diagram.

Fig. 2 be blade root, in, top area schematic.

When Fig. 3 is X > 0.45, blade loading is along the high regularity of distribution schematic diagram of leaf.

When Fig. 4 is X < 0.05, blade loading is along the high regularity of distribution schematic diagram of leaf.

Fig. 5 is 0.05≤X≤0.45 o'clock, and blade loading is along the high regularity of distribution schematic diagram of leaf.

Code name implication in figure: 1, the leading edge region in plane cascade runner, 2, the trailing edge region in plane cascade runner, 3, root of blade height region, 4, height region, blade middle part, 5, vane tip height region.

Embodiment

As shown in Fig. 1～5, the present invention is a kind of loading method of turbine blade, refers to that the load of vane type line is along the high controlling method distributing of leaf, and the load character of the two-dimentional blade profile of turbine blade is controlled by the geometric parameter UGT size of blade profile.Geometric parameter UGT is: adjacent blade profile inner arc exit point is carried on the back tangent line on the back of the body arc that arc beeline (throat position) loca is corresponding to adjacent blade profile, and the angle between the tangent line of blade profile back of the body arc exit point place blade profile back of the body arc, i.e. angle between the vertical line of the line of position OO of blade profile throat and blade profile back of the body arc exit point tangent line PP.Geometric parameter UGT is height H and the depth-width ratio H/C(blade height H/ root of blade chord length C by blade along the high Changing Pattern of leaf) determine, specific as follows:

, H-blade height wherein, C-root of blade chord length;

According to above formula, can tentatively determine that the influence area of secondary flow, the X in above formula represent root, the high proportion of the total leaf of the shared blade in secondary flow region, top.Therefore:

1. when X > 0.45, UGT1 is constant, between 16 ° ~ 22 °; As shown in Figure 3.

When X > 0.45, show that secondary flow proportion is larger, the secondary flow region sum of root, top area accounts for the proportion that total leaf is high and surpasses 90%.Now, the two-dimentional blade profile in whole blade height can be used a kind of rear loading blade profile, and rear loading level can be determined by blading nomenclature UGT1, generally between 16 ° ~ 22 °.

2. when X < 0.05, UGT2 is constant, between 4 ° ~ 10 °; As shown in Figure 5.

When X < 0.05, show that secondary flow proportion is less, the secondary flow region sum of root, top area accounts for the proportion that total leaf is high and is no more than 10%.Now, the two-dimentional blade profile in whole blade height can be used a kind of fore-loaded airfoil, and front loading level can be determined by blading nomenclature UGT2, generally between 4 ° ~ 10 °.

3. when 0.05≤X≤0.45, only use a kind of fore-loaded airfoil or after load blade profile and all cannot at utmost reduce flow losses, and rationally change blade profile load, along the high regularity of distribution of leaf, can reach the object of controlling secondary flow loss simultaneously and reducing profile loss, as shown in Figure 4, there are two kinds of situations:

A, in root of blade region, (0, X) and in the high scope of relative leaf of top area (1-X, 1), UGT3-1 distributes with parabola rule along leaf is high; Further, UGT3-1 is high as follows with parabola rule distribution mathematical model along leaf:

，0＜h≤X·H

，（1-X）·H＜h≤H

Wherein, h-is apart from the height of root, 0 < h≤H.

B, in the high scope of relative leaf of blade central region (X, 1-X), UGT3-2 is constant, the value of UGT3-2 is identical with above-mentioned UGT2.

This is the concrete regularity of distribution that meets load.

Claims (2)

1. the loading method of turbine blade, it is characterized in that: the load character of the two-dimentional blade profile of described turbine blade is controlled by the geometric parameter UGT size of blade profile, and geometric parameter UGT is: adjacent blade profile inner arc exit point is to tangent line on back of the body arc corresponding to adjacent blade profile back of the body arc beeline loca, carry on the back the angle between the tangent line of arc with blade profile back of the body arc exit point place blade profile; Geometric parameter UGT is as follows along the high Changing Pattern of leaf:

, H-blade height wherein, C-root of blade chord length;

1. when X > 0.45, UGT1 is constant, between 16 ° ~ 22 °;

2. when X < 0.05, UGT2 is constant, between 4 ° ~ 10 °;

3. when 0.05≤X≤0.45, in root of blade region, (0, X) and in the high scope of relative leaf of top area (1-X, 1), UGT3-1 distributes with parabola rule along leaf is high;

In the high scope of relative leaf of blade central region (X, 1-X), UGT3-2 is constant, and the value of UGT3-2 is identical with above-mentioned UGT2.

2. the loading method of turbine blade according to claim 1, is characterized in that: described UGT3-1 is high as follows with parabola rule distribution mathematical model along leaf:

，0＜h≤X·H

，（1-X）·H＜h≤H

Wherein, h-is apart from the height of root, 0 < h≤H.

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