CN212130558U - A turbine blade structure with a truncated rib and a trailing edge half-split slot - Google Patents

Abstract

The utility model provides a turbine blade structure with a truncated rib and a trailing edge half-split slot, which comprises a blade leading edge, a blade suction surface, a blade pressure surface, a trailing edge half-split slot surface, a separation rib and a lip; Part of the pressure sidewall surface is cut off in the edge area, and the suction sidewall surface of the trailing edge area of the blade is retained, and a plurality of trailing edge half-split slit structures are formed with the separation rib; a number of cutting ribs are arranged on the wall surface of the trailing edge half-split slit to cut off the length direction of the rib. Perpendicular to the inflow direction of low-temperature gas; along the length of the cut-off rib, a row of cut-off ribs is formed by several cut-off ribs; the length of a single cut-off rib is 1/4 to 1/3 of the width of the cold gas rectangular outlet, and the height of the cut-off rib is the cold gas rectangle. 1/5～1/2 of the height of the outlet; along the flow direction of the low-temperature gas, the ratio of the distance between the two adjacent rows of cut-off ribs to the cut-off rib degree is 4 to 10. The utility model effectively reduces the surface temperature of the blade pressure side and the suction side at the trailing edge, and achieves the purpose of improving the comprehensive cooling effect of the trailing edge half-split cooling structure.

Description

A turbine blade structure with a truncated rib and a trailing edge half-split slot

technical field

The utility model belongs to the technical field of gas turbine turbine blade cooling, in particular to a turbine blade structure with a truncated rib and a trailing edge half-split slot.

Background technique

As an important part of a gas turbine engine, the turbine's thrust characteristics and cycle efficiency can be effectively improved by increasing the temperature before the gas turbine. The research report shows that under the condition of keeping the engine size unchanged, the engine thrust can be increased by 8 to 13% and the engine cycle efficiency can be increased by 2 to 4% for every 56 ℃ increase in the turbine inlet temperature. One of the development directions of turbine blades, in order to ensure sufficient safety, reliability and service life of turbine blades in over-limit high-temperature service environments, efficient cooling measures must be taken for them.

Because the gas velocity on the pressure side and the suction side both reaches a very high value at the trailing edge of the turbine blade, and they are both in a turbulent state, the convective heat transfer intensity of the gas at the trailing edge is very high. However, with the continuous increase of the gas temperature of the aero-engine, the cooling capacity of the traditional half-split slot structure gradually tends to the limit, and the ablation of the trailing edge of the high-pressure turbine blade often occurs. Therefore, it is very necessary and meaningful for the development of advanced high-performance aero-engines to develop and innovate the high-efficiency cooling structure of the turbine blade trailing edge to further improve the cooling effect without increasing the amount of cold air.

In the document "Effect of spoiler column on convective heat transfer characteristics of blade trailing edge" (Journal of Aerodynamics, 2007, No. 10, pp. 18-22), the author used infrared thermometry to measure four different types of spoilers. The influence of the internal cooling channel of the flow column (cylindrical, elliptical, droplet type I, droplet type II) on the heat transfer coefficient of the turbine blade trailing edge. Film cooling has the largest convective heat transfer coefficient. Although the arrangement of cylindrical spoiler columns in the inner cooling channel can enhance the heat transfer coefficient of the trailing edge of the turbine blade, the increasing temperature before the turbine requires a more efficient cooling structure for the trailing edge of the blade. Therefore, without increasing the amount of cold air, It is necessary to develop a more efficient trailing edge cooling structure.

SUMMARY OF THE INVENTION

In order to further improve the cooling effect of the trailing edge of the blade, the utility model provides a turbine blade structure with a truncated rib and a semi-split slit on the trailing edge.

The technical scheme of the present utility model is:

The turbine blade structure with a truncated rib and a semi-split slit on the trailing edge includes a leading edge of the blade, a suction surface of the blade, a pressure surface of the blade, a cold flow inlet, a cooling cavity inside the blade, a surface of the semi-split slit on the trailing edge, and a partition rib and lip;

Cut off part of the pressure side wall surface in the blade trailing edge area, retain the suction side wall surface in the blade trailing edge area, and form a plurality of trailing edge semi-split slit structures with the separation ribs;

The low-temperature gas used to cool the surface of the half-split slit of the trailing edge is supplied from the cooling cavity inside the blade through the cold flow inlet. The split slit surface can isolate the high-temperature gas flowing through the half split slit surface from the top of the blade pressure surface and the half split slit surface, and at the same time cool the blade suction side wall surface through heat conduction;

The height ratio between the height of the lip plate in the half-split slot structure and the rectangular outlet formed between the partition ribs is 0.2 to 1.5, and the angle between the mainstream direction of the pressure side and the cold air flow direction in the half-split slot structure is 5 to 15°;

It is characterized in that: a number of truncation ribs are arranged on the wall surface of the semi-split seam of the trailing edge, and the length direction of the truncation rib is perpendicular to the inflow direction of the low temperature gas; along the length direction of the truncation rib, a row of truncation ribs is formed by several truncation ribs; a single truncation rib The length of the cold gas rectangular outlet is 1/4 to 1/3 of the width of the cold gas rectangular outlet, and the height of the cut-off rib is 1/5 to 1/2 of the height of the cold gas rectangular outlet. The ratio of the spacing to the truncated rib is 4 to 10.

Further, along the inflow direction of the low-temperature gas, the total number of rows of the cut-off ribs arranged on the surface of the half-split seam is four, and the arrangement is in a row or a staggered row.

beneficial effect

The advantages of the utility model: by arranging the truncated rib structure on the surface of the half-split seam, the surface of the half-split seam of the trailing edge can increase the heat exchange area through the turbulence structure without increasing the amount of cold air, and at the same time increase the heat transfer area to the fluid. Disturbance effect to improve the convective heat transfer effect on the surface of the half-split slot, and at the same time to ensure a small decrease in the cooling efficiency of the air film on the surface of the half-split slot, thereby effectively reducing the pressure side and suction side of the blade on the trailing edge. The purpose of improving the comprehensive cooling effect of the trailing edge half-split cooling structure is finally achieved. At the same time, the new turbine blade trailing edge cooling structure with the truncated rib turbulence structure proposed by the present invention only arranges simple truncated ribs on the surface of the half-split slit, which makes it have good processability and can be easily applied to various in the cooling design of the trailing edge of a turbine blade.

Additional aspects and advantages of the invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of the structure of a turbine blade with a truncated rib and a half-split slit on the trailing edge of the present invention.

2 is a partial enlarged view of the trailing edge region of a turbine blade structure with a truncated rib and a trailing edge half-split slot of the present invention.

Fig. 3 is the distribution cloud map of the Nusselt number ratio between the surface of the turbulent half-split seam and the smooth half-split seam surface of the turbulent flow structure with the truncated rib.

Fig. 4 is the cloud diagram and streamline diagram of the surface velocity distribution of the turbulent half-split slit with the truncated rib turbulent flow structure.

In the picture: 1 blade leading edge, 2 blade suction surface, 3 blade pressure surface, 4 blade inner cooling cavity, 5 trailing edge area, 6 cold air inlet, 7 truncation rib, 8 half split surface.

Detailed ways

The following describes the embodiments of the present invention in detail. The embodiments are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

Example 1:

This embodiment is a turbine blade structure with a trailing edge half-split slit with a truncated rib. Referring to FIGS. 1 to 4 , the turbine blade structure with a trailing edge half-split slit with a truncated rib in this embodiment is applied to the trailing edge region of the turbine blade, including the leading edge of the blade, the suction surface of the blade, the pressure surface of the blade, and the interior of the blade. Cooling cavity, trailing edge area, cold air inlet, cut-off rib, half-split seam surface, partition rib, lip.

In order to reduce the thickness of the trailing edge, part of the pressure sidewall surface is cut off in the trailing edge area of the blade, the suction sidewall surface in the trailing edge area of the blade is retained, and multiple trailing edge half-split slit structures are formed with the separation ribs; The low-temperature gas is supplied from the cooling cavity inside the blade, and the low-temperature gas can be ejected from the rectangular outlet formed between the partition ribs. The high-temperature gas on the surface of the split seam is isolated from the surface of the half-split seam to prevent the high-temperature gas from ablating the trailing edge. At the same time, the suction side wall surface of the blade is affected by the high-temperature gas, and the temperature of the wall surface will be higher than the surface temperature of the half-split seam. The blade suction sidewall surface is cooled.

The ratio of the height of the lip plate in the half-split slot structure to the rectangular outlet formed between the partition ribs is 0.5, and the angle between the main flow direction of the pressure side and the cold air flow direction in the half-split slot structure is 15°.

There are 4 rows of cut-off ribs on the wall surface of the half-split slit of the trailing edge corresponding to a single rectangular outlet, and the length direction of the cut-off ribs is perpendicular to the direction of low-temperature gas flow; the arrangement is staggered, and each row of cut-off ribs consists of 1 to 2 It consists of cut-off ribs; the length of a single cut-off rib is 1/4 of the width of the rectangular outlet of the cold gas, and the height of the cut-off rib is 1/5 of the height of the rectangular outlet of the cold gas; along the flow direction of the low-temperature gas, the distance between two adjacent rows of cut-off ribs The ratio to the truncated rib is 5.

In this embodiment, the low-temperature gas from the cooling cavity inside the blade enters through the cold-air inlet, and is ejected from the rectangular outlet formed by the partition ribs. The surface of the half-split slit with the cut-off ribs is mixed with the high-temperature gas passing through the pressure surface of the blade. mixed phenomenon. By arranging the cutting rib on the half-split surface of the trailing edge, the cooling fluid on the half-split surface is separated by flow, and the fluid is reattached. It also increases the heat exchange area of the surface of the half-split slit, thereby enhancing the convective heat transfer coefficient between the surface of the half-split slit and the cooling fluid, and improving the comprehensive cooling effect of the trailing edge.

Figures 3 and 4 show the Nusselt number ratio distribution cloud map, surface velocity distribution cloud map and streamline diagram of the turbulent half-split surface and the smooth half-split surface with the truncated rib spoiler structure. Flowing through the rib interrupted section, the airflow near the wall surface due to the reduction of the flow area, most of the airflow shrinks and converges and flows out from the gap of the rib interrupted section or the truncated section, so that the jet velocity is accelerated, and the accelerated jet downstream goes around the backward section to cut off the rib, and A large spanwise recirculation vortex is generated behind the rib. With the reduction of the length of the truncated rib in the rearward section, its turbulent effect on the outflow jet from the notch in the discontinuous rib is weak, and the heat transfer effect is weakened. For the rib end wall of the truncated rib, due to the direct impact and turbulence of the wall air flow, the heat exchange intensity is high, and the area behind the rib end is a high heat exchange area. The heat transfer coefficient of the centerline attachment of the half-split seam surface is relatively low. With the increase of the length of the truncated rib in the rearward section, the heat transfer coefficient of the high heat transfer area at the rear of the rib end increases gradually, and the range expands. From the Nusselt number ratio distribution cloud map, it can be seen that the heat transfer coefficient of the surface of the half-split slit with truncated ribs is indeed higher than that of the smooth half-split structure. The turbine blade trailing edge cooling structure can indeed improve the overall cooling effect of the trailing edge.

Example 2:

This embodiment is a turbine blade structure with a trailing edge half-split slit with a truncated rib. The turbine blade structure with a truncated rib and a trailing edge half-split slot in this embodiment is applied to the trailing edge region of the turbine blade, including the leading edge of the blade, the suction surface of the blade, the pressure surface of the blade, the cooling cavity inside the blade, the trailing edge area, Air-conditioning inlet, cut-off rib, half-split seam surface, partition rib, lip plate.

In order to reduce the thickness of the trailing edge, part of the pressure sidewall surface is cut off in the trailing edge area of the blade, the suction sidewall surface in the trailing edge area of the blade is retained, and multiple trailing edge half-split slit structures are formed with the separation ribs; The low-temperature gas is supplied from the cooling cavity inside the blade, and the low-temperature gas can be ejected from the rectangular outlet formed between the partition ribs. The ejected gas covers the surface of the half-split slit where the partition ribs are arranged, and can flow through the half-split from above the pressure surface of the blade. The high-temperature gas on the surface of the split seam is isolated from the surface of the half-split seam to prevent the high-temperature gas from ablating the trailing edge. At the same time, the suction side wall surface of the blade is affected by the high-temperature gas, and the temperature of the wall surface will be higher than the surface temperature of the half-split seam. The blade suction sidewall surface is cooled.

The height ratio between the height of the lip plate in the half-split slot structure and the rectangular outlet formed between the partition ribs is 0.2, and the angle between the main flow direction of the pressure side and the cold air flow direction in the half-split slot structure is 10°.

There are 4 rows of cut-off ribs on the wall surface of the half-split seam at the trailing edge corresponding to a single rectangular outlet, and the length direction of the cut-off ribs is perpendicular to the direction of low-temperature gas flow; ; The length of a single truncated rib is 1/3 of the width of the rectangular outlet of the cold gas, and the height of the truncated rib is 1/2 of the height of the rectangular outlet of the cold gas; along the flow direction of the low-temperature gas, the distance between the two adjacent rows of truncated ribs is the same as the truncated rib. The degree ratio is 4.

Example 3:

This embodiment is a turbine blade structure with a truncated rib and a trailing edge half-split slot. The turbine blade structure with a truncated rib and a trailing edge half-split slot in this embodiment is applied to the trailing edge region of the turbine blade, including the leading edge of the blade, the suction surface of the blade, the pressure surface of the blade, the cooling cavity inside the blade, the trailing edge area, Air-conditioning inlet, cut-off rib, half-split seam surface, partition rib, lip plate.

In order to reduce the thickness of the trailing edge, part of the pressure sidewall surface is cut off in the trailing edge area of the blade, the suction sidewall surface in the trailing edge area of the blade is retained, and multiple trailing edge half-split slit structures are formed with the separation ribs; The low-temperature gas is supplied from the cooling cavity inside the blade, and the low-temperature gas can be ejected from the rectangular outlet formed between the partition ribs. The ejected gas covers the surface of the half-split slit where the partition ribs are arranged, and can flow through the half-split from above the pressure surface of the blade. The high-temperature gas on the surface of the split seam is isolated from the surface of the half-split seam to prevent the high-temperature gas from ablating the trailing edge. At the same time, the suction side wall surface of the blade is affected by the high-temperature gas, and the temperature of the wall surface will be higher than the surface temperature of the half-split seam. The blade suction sidewall surface is cooled.

The height ratio between the height of the lip plate in the half-split slot structure and the rectangular outlet formed between the partition ribs is 1.5, and the angle between the main flow direction of the pressure side and the cold air flow direction in the half-split slot structure is 5°.

There are 4 rows of cut-off ribs on the wall surface of the half-split seam at the trailing edge corresponding to a single rectangular outlet, and the length of the cut-off ribs is perpendicular to the direction of low-temperature gas flow; Rib composition; the length of a single truncated rib is 1/3 of the width of the rectangular outlet of the cold gas, and the height of the truncated rib is 1/3 of the height of the rectangular outlet of the cold gas; The truncated rib degree ratio is 10.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limitations of the present invention. Variations, modifications, substitutions, and alterations to the above-described embodiments are possible within the scope of the present invention without departing from the principles and principles.

Claims (2)

1. A turbine blade structure with a trailing edge half-split slot with a truncated rib, comprising a blade leading edge, a blade suction surface, a blade pressure surface, a cold flow inlet, a cooling cavity inside the blade, a trailing edge half-split slot surface, and a partition rib and lip; Cut off part of the pressure side wall surface in the blade trailing edge area, retain the suction side wall surface in the blade trailing edge area, and form a plurality of trailing edge semi-split slit structures with the separation ribs; The low-temperature gas used to cool the surface of the half-split slit of the trailing edge is supplied from the cooling cavity inside the blade through the cold flow inlet. The split slit surface can isolate the high-temperature gas flowing through the half split slit surface from the top of the blade pressure surface and the half split slit surface, and at the same time cool the blade suction side wall surface through heat conduction; The height ratio between the height of the lip plate in the half-split slot structure and the rectangular outlet formed between the partition ribs is 0.2 to 1.5, and the angle between the mainstream direction of the pressure side and the cold air flow direction in the half-split slot structure is 5 to 15°; It is characterized in that: a number of truncation ribs are arranged on the wall surface of the semi-split seam of the trailing edge, and the length direction of the truncation rib is perpendicular to the inflow direction of the low temperature gas; along the length direction of the truncation rib, a row of truncation ribs is formed by several truncation ribs; a single truncation rib The length of the cold gas rectangular outlet is 1/4 to 1/3 of the width of the cold gas rectangular outlet, and the height of the cut-off rib is 1/5 to 1/2 of the height of the cold gas rectangular outlet. The ratio of the spacing to the truncated rib is 4 to 10. 2. The turbine blade structure of a trailing edge half-split slit with a truncation rib according to claim 1, is characterized in that: along the low-temperature gas inflow direction, the total number of rows of the truncation rib arranged on the half-split slit surface is four. Arrangement in sequential or staggered arrangement.

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