CN114412645A - Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber - Google Patents
Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber Download PDFInfo
- Publication number
- CN114412645A CN114412645A CN202111606243.6A CN202111606243A CN114412645A CN 114412645 A CN114412645 A CN 114412645A CN 202111606243 A CN202111606243 A CN 202111606243A CN 114412645 A CN114412645 A CN 114412645A
- Authority
- CN
- China
- Prior art keywords
- cooling
- plate
- slit
- impact
- contraction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/12—Cooling of plants
- F02C7/16—Cooling of plants characterised by cooling medium
- F02C7/18—Cooling of plants characterised by cooling medium the medium being gaseous, e.g. air
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
Abstract
The invention relates to a cooling structure of a ribbed plate with a slit for a turbofan engine combustion chamber.A plurality of annular fins with high blocking ratio are arranged on the surface of an air film pore plate in an impact air flow cooling channel along the air flow direction, the annular fins with high blocking ratio are parallel to each other, at least two contraction or expansion slits for improving the heat exchange uniformity are arranged on the annular fins with high blocking ratio along the cooling air flow direction, and the at least two contraction or expansion slits are arranged on the annular fins with high blocking ratio at intervals; after the wall surface of the impact target plate is provided with the contraction/expansion type slit ribs, the heat transfer performance of a low heat transfer area between impact jet flow areas on the impact target plate in the traditional impact cooling is improved, so that the heat transfer uniformity of the wall surface of the impact target plate is improved.
Description
Technical Field
The present invention relates to an engine cooling structure, and more particularly to a cooling structure for a combustion chamber of a high bypass ratio turbofan engine.
Background
The aircraft engine develops from the second generation to the fourth generation, the wall temperature of the combustion chamber of the aircraft engine is increased by 300 ℃ per generation, and the increase of the temperature brings more serious challenges to the structural design, the working stability and the like of the combustion chamber of the aircraft engine, wherein the combustion chamber is a key part for determining the service life and the reliability of a turbofan engine, and the combustion chamber is directly impacted by high-temperature gas during working. The two trends of researching the stability of the aero-engine are to find the development of the high-temperature resistant alloy material field and to adopt a more efficient cooling technology, and at present, the development of the high-temperature resistant alloy material is far behind the increasing speed of the temperature of the combustion chamber, so that a more effective cooling mode must be adopted to reduce the working temperature of the combustion chamber and ensure the normal operation of the engine.
Impingement-film double-wall cooling techniques have received much attention from researchers because they adequately combine the advantages of both internal impingement cooling and external film cooling. In the impact/air film double-wall air film cooling structure, cold air flows out of impact holes on the impact plate and then generates impact heat exchange with the inner wall surface of the air film plate, so that the heat exchange effect of the area near the stagnation point is obviously improved. Wall efflux then takes place the interact from the gas film hole outflow on the gas film board with mainstream high temperature gas, forms the gas film cooling, avoids high temperature gas and wall direct contact, plays the effect that reduces the temperature of blade surface. Compared with other single traditional methods such as internal convection cooling, impingement cooling and film cooling, the impingement-film cooling technology can provide better cooling performance and higher cooling efficiency.
In order to further improve the internal impact cooling characteristic of the impact-air film double-wall cooling structure, different types of rough turbulence elements, such as turbulence columns, fins and surface-recessed vortex generators, are arranged on a target surface (the inner wall surface of an air film plate). The cooling structure is called as a laminated plate structure, and the arranged turbulence elements not only increase the mixing degree with the cooling gas flowing through the cooling channel, but also increase the surface area for heat exchange, thereby increasing the heat exchange strength of the inner wall surface of the air film plate in the laminated plate structure. In the application of a common laminate cooling structure, the inner wall surface of the air film plate is mainly provided with solid turbulence columns and turbulence ribs with different shapes, blockage ratios, spacing ratios and arrangement modes.
The prior literature research shows that the fins with high blocking ratio can effectively weaken the influence of cross flow on impact heat exchange and enhance the overall heat exchange characteristic, but the fins can also cause uneven heat flux distribution on the inner wall of the engine with high bypass ratio, thereby causing local high temperature gradient and thermal failure. Therefore, the cooling structure with excellent heat exchange strength and good heat exchange uniformity is designed, and the cooling structure has important significance for safe and stable work of the high bypass ratio engine.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a cooling structure with a slit rib layer plate for a turbofan engine combustion chamber, wherein the cooling structure has excellent heat exchange strength and better heat exchange uniformity.
In order to achieve the purpose, the invention adopts the technical scheme that: a cooling structure of a laminated plate with a slit rib for a combustion chamber of a turbofan engine comprises a gas film hole plate and an impact hole plate, wherein the impact hole plate and the gas film hole plate are arranged in parallel, an impact airflow cooling channel is arranged between the gas film hole plate and the impact hole plate, and the gas film hole plate, the impact hole plate and the impact airflow cooling channel form a double-layer wall structure of a liner of the combustion chamber of the turbofan engine;
the surface of the air film pore plate in the impinging stream cooling channel is provided with a plurality of annular fins with high blocking ratio along the air flow direction, the annular fins with high blocking ratio are parallel to each other, at least two contraction or expansion slits for improving the heat exchange uniformity are arranged on the annular fins with high blocking ratio along the cooling air flow direction, and the at least two contraction or expansion slits are arranged on the annular fins with high blocking ratio at intervals;
the cooling air flow enters the slit from the slit inlet of the contraction or expansion slit and flows out from the slit outlet, and when the height of the slit inlet of the contraction or expansion slit is higher than that of the slit outlet, the contraction or expansion slit is a contraction slit; when the height of the slit inlet is lower than that of the slit outlet, the contraction or expansion slit is an expansion slit; the surfaces of the upper slit and the lower slit of the contraction or expansion slit are obliquely arranged at a contraction or expansion angle;
the impact pore plate is provided with impact pores, the air film pore plate is provided with air film pores, the pore diameters of the impact pores and the air film pores are the pore diameters d, and the distance between the high-blockage-ratio annular fins and the air film pores is 1-5 d along the direction of cooling air flow after the high-blockage-ratio annular fins are located in the air film pores.
Further, the impact orifice plate is an air inlet plate and is arranged on the cold air side of the combustion chamber; the gas film pore plate is a gas outlet plate and is arranged on the gas side of the combustion chamber; the thickness of the impact orifice plate and the thickness of the air film orifice plate are both 0.5-3 d, and the width in the spreading direction is both 4-8 d.
Further, strike the orifice plate on even equidistance be equipped with the impact hole the air film orifice plate on even equidistance be equipped with the air film hole, the air film hole with strike hole staggered arrangement and arrange, strike the crisscross interval of hole and air film hole and be 2 ~ 4 d.
Further, the impact holes and the air film holes are respectively arranged on the impact hole plate and the air film hole plate in a direction perpendicular to the main air flow, the aperture d of the impact holes and the air film holes is 2-10 mm, and the relative distance between every two adjacent impact holes and between every two adjacent air film holes along the air flow direction and the spreading direction is 4-8 d.
Furthermore, the hole types of the impact hole and the air film hole are both cylindrical holes.
Furthermore, the section of the high blockage ratio annular rib is square, and the ratio of the height e of the high blockage ratio annular rib to the height H of the impinging stream cooling channel is 0.2-0.5.
Furthermore, the section of the annular rib with the high blockage ratio is square, the ratio of the height e of the annular rib with the high blockage ratio to the height c of the contraction or expansion slit is 0.2-0.5, and the penetration rate beta of the contraction or expansion slit is as follows:
in the formula c1Is the height of the slit entrance, c2The height of the slit exit.
Further, the ratio of the height H of the impingement airflow cooling channel to the aperture d is 0.5-3.
Furthermore, the contraction or expansion slits are uniformly distributed on the annular rib with the high blockage ratio at intervals, and the contraction or expansion slits and the solid part 1:1 of the rib are arranged to ensure structural support.
The invention also provides a cooling method of the cooling structure of the laminated plate with the slit ribs for the combustion chamber of the turbofan engine, which comprises the following steps:
the cooling air flow carries out impact heat exchange on the inner wall surface of the air film pore plate through the impact hole, the cooling air flow impacting the air film pore plate is diffused around to form wall surface jet flow A, and then cross flow B is formed along the direction of the cold air flow; at the moment, the annular rib with the high blockage ratio has a blockage effect on cooling airflow, and the transverse flow B interacts with a descending separation flow C formed on the upper surface of the annular rib with the high blockage ratio to form a large reflux area D;
when the contraction or expansion slit is an expansion slit, part of cooling air flow in the impact air flow cooling channel is sprayed out from the expansion slit to interact with the large reflux area D, and an angular vortex E with opposite rotation direction is formed at the outlet of the expansion slit, namely, a low-speed secondary flow area immediately adjacent to the high blockage ratio annular fin is reduced, so that the heat exchange characteristic of a near-rib area is improved; meanwhile, due to the existence of the angular vortex E, the size of the large reflux area D is reduced and the large reflux area D moves to the downstream of the annular rib with high blocking ratio, so that the range of the high heat exchange coefficient area is weakened, and the convection heat exchange coefficient of the impact target surface is distributed more uniformly;
when the contraction or expansion slit is a contraction slit, part of cooling air flow in the impact air flow cooling channel is ejected from the contraction slit to interact with the large backflow area D, a first angular vortex F with opposite rotation direction is formed at the outlet of the expansion slit, and meanwhile, the separation flow C also interacts with the large backflow area D to form a second angular vortex G with the same rotation direction at the downstream of the upper surface of the annular rib with the high blockage ratio, namely, a low-speed secondary flow area immediately behind the annular rib with the high blockage ratio is reduced, so that the heat exchange characteristic of a near rib area is improved; meanwhile, due to the existence of the first angular vortex F and the second angular vortex G, the size of the large reflux area C is reduced and the large reflux area C moves to the downstream of the annular rib with high blocking ratio, so that the range of the high heat exchange coefficient area is weakened, and the convection heat exchange coefficient of the impact target surface is distributed more uniformly;
and finally, part of cooling air flow enters the air film hole to continuously carry out convective heat transfer, and then is blown to the outer wall surface of the air film hole to form an air film, so that the high-temperature gas is prevented from ablating the air film hole plate, and the other part of cooling air flow is discharged from the outlet of the combustion chamber.
The invention has the beneficial effects that:
in order to maximally improve the heat exchange of the impact/gas film double-wall structure and further improve the cooling efficiency of the structure while ensuring the uniformity of the heat exchange, the invention provides a contraction/expansion type slit rib plate cooling structure capable of improving the internal cooling characteristic of a combustion chamber high-bypass-ratio engine. The narrow slit rib with high blocking ratio is arranged behind the air film hole, so that the upward deflected wall surface jet flow generated in the upstream area of the impact hole is mixed with the downward flow separated from the upper surface of the adjacent rib, and a small backflow area is generated behind the rib, thereby inhibiting the cross flow and enhancing the whole heat exchange of the structure. In addition, after the wall surface of the impact target plate is provided with the contraction/expansion type slit ribs, the heat transfer performance of a low heat transfer area between impact jet flow areas on the impact target plate in the traditional impact cooling is improved, so that the heat transfer uniformity of the wall surface of the impact target plate is improved.
The invention provides a contraction/expansion type slit rib layer plate cooling structure capable of improving the internal cooling characteristic of a combustion chamber high-bypass-ratio engine. The method comprises the steps of firstly, arranging the annular fins with high blocking ratio on an impact target surface to improve the internal heat exchange effect of the engine with high bypass ratio, and then arranging gaps in the middle of the fins to improve the heat exchange uniformity of the wall surface while enhancing the heat exchange strength. In addition, because the fins strengthen the disturbance of cooling air flow, the convection heat exchange between fluid and solid in the double-layer wall is strengthened, and the total heat transfer quantity is correspondingly increased after the fins are arranged. Meanwhile, the fins weaken the development of transverse flow, so that more cooling air flows out of the air film holes to be mixed with high-temperature fuel gas, the air film cooling efficiency is improved, and finally the comprehensive cooling effect of the laminated plate structure is enhanced.
Drawings
FIG. 1 is a schematic view of the application of the cooling structure of the present invention to a high bypass ratio turbofan engine combustor;
FIG. 2 is a schematic structural view of the present invention;
FIG. 3 is a schematic sectional view showing the structure of embodiment 1 of the present invention;
FIG. 4 is an enlarged sectional view of the annular rib of high plug ratio in example 1 of the present invention;
FIG. 5 is a schematic view of the cooling principle of embodiment 1 of the present invention;
FIG. 6 is a schematic sectional view showing embodiment 2 of the present invention;
FIG. 7 is an enlarged cross-sectional view of the annular rib of high blockage ratio in accordance with example 2 of the present invention;
FIG. 8 is a schematic view of the cooling principle of embodiment 2 of the present invention;
FIG. 9 is a schematic top view of the high blockage ratio annular fin structure of the present invention;
FIG. 10 is a schematic view of the cooling principle of a seamless high blockage ratio annular fin structure;
FIG. 11 is a schematic view of the impact target surface Knoop number distribution of a seamless high blockage ratio annular fin structure;
FIG. 12 is a schematic Nursery number distribution of an impact target surface of example 1 of the present invention;
FIG. 13 is a schematic view of the Knoop number distribution of an impact target surface of example 2 of the present invention;
FIG. 14 is a diagram showing the effect of the characteristic of the uniformity of heat exchange according to the variation of Reynolds number.
In the figure, 1, an impact hole, 2, an impact orifice plate, 3, an impact airflow cooling channel, 4, a high blockage ratio annular rib, 41, a contraction or expansion slit, 42, a slit inlet, 43, a slit outlet, 5, a gas film hole and 6, a gas film orifice plate.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.
In order to achieve the above object, the present invention provides the following embodiments:
the air of the outer duct of the engine only passes through the fan, the flow rate is low and low temperature, high-temperature fuel gas is discharged from the inner duct, the average flow rate and temperature of the nozzle are reduced after the two gases are mixed, the lower flow rate brings higher propelling efficiency and lower noise, and the lower temperature can bring higher thermodynamic efficiency according to the heat engine principle. The two factors act together to ensure that the turbofan engine can obtain larger thrust than the turbojet engine under the condition of the same oil consumption, so that the thrust and the service life of the engine are further improved after the turbofan engine is applied to a combustion chamber lining structure of the turbofan engine, and the specifically adopted embodiment of the invention is as follows:
example 1: as shown in fig. 1-4, a cooling structure of a laminated plate with a slit rib for a combustion chamber of a turbofan engine comprises a gas film orifice plate 6 and an impact orifice plate 2, wherein the impact orifice plate 2 and the gas film orifice plate 6 are arranged in parallel, an impact airflow cooling channel 3 is arranged between the gas film orifice plate 6 and the impact orifice plate 2, and the gas film orifice plate 6, the impact orifice plate 2 and the impact airflow cooling channel 3 form a double-wall structure of an inner liner of the combustion chamber of the turbofan engine;
a plurality of annular fins 4 with high blocking ratio are arranged on the surface of the air film pore plate 6 in the impinging air flow cooling channel 3 along the air flow direction, the annular fins 4 with high blocking ratio are parallel to each other, at least two contraction or expansion slits 41 for improving the heat exchange uniformity are arranged on the annular fins 4 with high blocking ratio along the cooling air flow direction, and the at least two contraction or expansion slits 41 are arranged on the annular fins 4 with high blocking ratio at intervals; the converging or diverging slots 41 are evenly spaced on the high blockage ratio annular rib 4, the converging or diverging slots 41 and rib solid portions 1:1 being arranged to ensure structural support.
The cooling air flow enters the slot from the slot entrance 42 of the contraction or expansion slot 41 and flows out from the slot exit 43, the contraction or expansion slot 41 is a contraction slot, and the slot entrance 42 of the contraction slot is higher than the slot exit 43; and the upper and lower slit surfaces of the contraction or expansion slit 41 are arranged obliquely at a contraction or expansion angle;
the impact pore plate 2 is provided with an impact pore 1, the air film pore plate 6 is provided with an air film pore 5, the pore diameters of the impact pore 1 and the air film pore 5 are both the pore diameter d, the high blocking ratio annular rib 4 is positioned behind the air film pore 5 along the direction of cooling air flow, and the distance between the high blocking ratio annular rib 4 and the air film pore 5 is 1-5 d; the ratio of the height H to the aperture d of the impingement airflow cooling channel 3 is 0.5-3.
The impact orifice plate 2 is an air inlet plate and is arranged on the cold air side of the combustion chamber; the gas film pore plate 6 is a gas outlet plate, and the gas film pore plate 6 is arranged on the gas side of the combustion chamber; the thickness of strikeing orifice plate 2 and gas film orifice plate 6 is 0.5 ~ 3d, and the span is to the width 4 ~ 8d, and even equidistance is equipped with impact hole 1 on strikeing orifice plate 2, and even equidistance is equipped with gas film hole 5 on gas film orifice plate 6, and gas film hole 5 and impact hole 1 staggered arrangement arrange, and impact hole 1 and the crisscross interval of gas film hole 5 are 2 ~ 4 d.
The impact holes 1 and the air film holes 5 are respectively arranged on the impact hole plate 2 and the air film hole plate 6 in a direction perpendicular to the main air flow, the aperture d of the impact holes 1 and the aperture d of the air film holes 5 are 2-10 mm, and the relative distance between the adjacent impact holes 1 and the adjacent air film holes 5 along the air flow direction and the spreading direction is 4-8 d. The hole patterns of the impact holes 1 and the air film holes 5 are both cylindrical holes.
The section of the high blockage ratio annular rib 4 is square, and the ratio of the height e of the high blockage ratio annular rib 4 to the height H of the impinging stream cooling channel 3 is 0.2-0.5; the ratio of the height e of the annular rib 4 with a high plugging ratio to the height c of the contraction or expansion slit 41 is 0.2 to 0.5, and the penetration rate beta of the contraction or expansion slit 41 is:
in the formula c1Is the height of the slit entrance 42, c2The height of the slit exit 43.
Example 2: as shown in fig. 5, the present invention provides a cooling method of a cooling structure of a slit-ribbed plate for a combustion chamber of a turbofan engine according to embodiment 1, including the steps of:
the cooling airflow carries out impact heat exchange on the inner wall surface of the air film pore plate 6 through the impact holes 1, the cooling airflow impacting the air film pore plate 6 is diffused around to form wall surface jet flow A, and then cross flow B is formed along the direction of the flow direction of the cold air; at this time, the high blockage ratio annular fin 4 blocks the cooling airflow, and the cross flow B interacts with the descending separation flow C formed on the upper surface of the high blockage ratio annular fin 4 to form a large reflux area D;
part of cooling air flow in the impact air flow cooling channel 3 is ejected from the contraction slit to interact with the large reflux area D, a first angular vortex F with opposite rotation direction is formed at the outlet of the expansion slit, meanwhile, the separation flow C also interacts with the large reflux area D, a second angular vortex G with the same rotation direction is formed at the lower part of the upper surface of the high blockage ratio annular rib 4, namely, a low-speed secondary flow area which is close to the high blockage ratio annular rib 4 is increased, and therefore the heat exchange characteristic of the near rib area is improved; meanwhile, due to the existence of the first angular vortex F and the second angular vortex G, the size of the large reflux area C is reduced and the large reflux area C moves to the downstream of the annular rib 4 with high blocking ratio, so that the range of the high heat exchange coefficient area is weakened, and the convection heat exchange coefficient of the impact target surface is distributed more uniformly;
and finally, part of cooling air flow enters the air film hole 5 to continuously carry out convective heat transfer, and then is blown to the outer wall surface of the air film hole 5 to form an air film, so that the high-temperature fuel gas is prevented from ablating the air film hole plate 6, and the other part of cooling air flow is discharged from the outlet of the combustion chamber.
Example 3: as shown in fig. 6 to 7, the same as in example 1, except that: the converging or diverging slots 41 are diverging slots with the slot entrance 42 height being lower than the slot exit 43 height.
Example 4: as shown in fig. 8, the present invention provides a cooling method of a cooling structure of a slit rib laminate for a combustion chamber of a turbofan engine according to embodiment 3, comprising the steps of:
the cooling airflow carries out impact heat exchange on the inner wall surface of the air film pore plate 6 through the impact holes 1, the cooling airflow impacting the air film pore plate 6 is diffused around to form wall surface jet flow A, and then cross flow B is formed along the direction of the flow direction of the cold air; at this time, the high blockage ratio annular fin 4 blocks the cooling airflow, and the cross flow B interacts with the descending separation flow C formed on the upper surface of the high blockage ratio annular fin 4 to form a large reflux area D;
part of cooling air flow in the impact air flow cooling channel 3 is sprayed out from the expansion slit to interact with the large reflux area D, and an angular vortex E with opposite rotation direction is formed at the outlet of the expansion slit, namely, a low-speed secondary flow area which is close to the annular rib 4 with high blocking ratio is increased, so that the heat exchange characteristic of the near-rib area is improved; meanwhile, the size of the large reflux area D is reduced and the large reflux area D moves to the downstream of the annular rib 4 with high blockage ratio due to the existing angular vortex E, so that the range of the high heat exchange coefficient area is weakened, and the convection heat exchange coefficient of the impact target surface is distributed more uniformly;
and finally, part of cooling air flow enters the air film hole 5 to continuously carry out convective heat transfer, and then is blown to the outer wall surface of the air film hole 5 to form an air film, so that the high-temperature fuel gas is prevented from ablating the air film hole plate 6, and the other part of cooling air flow is discharged from the outlet of the combustion chamber.
Specific example 1: as shown in fig. 9, the same as in example 1, except that: the invention provides a cooling structure of a laminated plate with a slit rib for a combustion chamber of a turbofan engine, which is mainly applied to a liner structure of the combustion chamber of the turbofan engine. The air-cooling type air-cooling heat exchanger is composed of air film holes 5, air film pore plates 6, an impact channel 3 between double-layer walls, contraction/expansion type slit ribs 4, impact holes 1 and impact pore plates 2, wherein the impact pore plates are air inlet plates and are close to cold air sides, a plurality of impact holes 1 perpendicular to the main air flow direction are uniformly and equidistantly arranged on the impact plates, the aperture d of each impact hole is 5mm, and the impact holes 1 are arranged along the cooling air flow direction PfA relative distance P from the spanwise directionjAre all 6 d; the gas film pore plate 6 is a gas outlet plate, the gas film pore plate 6 is close to the gas side, the plate is provided with gas film pores 5 which are perpendicular to the main flow direction and are arranged in an array, the pore diameter of each gas film pore 5 is d, and the gas film pores 1 are arranged along the flow direction P of the cooling gas flowfA relative distance P from the spanwise directionjAre all 6 d; and the air film holes 5 and the impact holes 1 are arranged in a staggered way at a distance PxThe thickness of the impact orifice plate 2 and the thickness of the air film orifice plate 6 are both 1.5 d; impact distance, i.e. impact hole 1 and impact target surfaceThe ratio of the distance of the impact hole 1 to the diameter d of the impact hole 1 is 1, the impact target surface refers to the inner wall surface of the air film pore plate 6, and the distance between the impact hole 1 and the impact target surface is also the height H of the impact airflow cooling channel 3; the hole patterns of the impact holes 1 and the air film holes 5 are both cylindrical holes. The high blockage ratio annular fin 4 is arranged on a gas film hole plate 6 in the impingement airflow cooling channel 3, and the opposite position is located behind the gas film hole 5, and the distance Pr is 1.5 d.
The width of the gas film pore plate 6 and the width of the impact pore plate 2 in the stretching direction are both 6d, the contraction/expansion type slit rib 4 is a square rib, the ratio of the height of the rib to the height of the impact channel is 0.3, and the penetration rate beta is 0.05 and 0.4;
at this time, the heat exchange uniformity is defined as follows:
in the formula, Ap represents the area of the inner side (cold air side) of the gas film orifice plate 6, Nu (r) represents the Nussell value of each position on the film orifice plate 6,
the average Knudel number of the surface of the membrane orifice plate 6 is represented, the meaning of the formula is equivalent to that a standard deviation is made on the distribution of the Knudel number of the membrane orifice plate 6, so that the nonuniformity of the Knudel number distribution can be seen, and an effect schematic diagram of the heat exchange uniformity along with the change of the Reynolds number as shown in FIG. 14 is drawn, as can be seen from FIG. 14, the smaller the nonuniformity is, the better the heat exchange uniformity of the impact target surface is, and the black color represents the solid rib. This example is mainly compared with the solid ribs, and it can be seen from the figure that the perforated ribs have less unevenness than the solid ribs, which means more uniform heat exchange.
Meanwhile, if the invention does not adopt fins of slit structures, but solid fins, as shown in fig. 10, due to the blocking effect of the high blocking ratio annular fins on the fluid, the cooling air flow impacting the air film orifice plate 6 is diffused all around to form wall surface jet flow a, and then forms cross flow B along the direction of the cold air flow; the cross flow B interacts with the separated flow C on the upper surface of the annular rib 4 with high blockage ratio to form a large recirculation zone D; when the invention is used, when contraction seams are formed on the ribs, airflow can blow off the angular vortexes I on the upstream of the fins, and meanwhile, the size of the main reflux area D is larger and is close to the solid ribs, so that the refrigerating effect around the solid ribs is uneven.
As shown in fig. 11, which is a schematic view of the knoop distribution of the impact target surface of the seamless high plug ratio annular fin structure, it can be seen that the area of the high heat exchange zone at the impact stagnation point is larger in the case of solid ribs.
FIG. 12 is a schematic Nursery number distribution of an impact target surface of example 1 of the present invention; FIG. 13 is a schematic view of the Knoop number distribution of an impact target surface of example 3 of the present invention; as can be seen from fig. 12 and 13, compared with fig. 11, the area of the high heat exchange area at the high impact stagnation point is obviously reduced after the slits are arranged, and the low heat exchange area at the upstream of the fins is also correspondingly reduced, so that the heat exchange of the impact target surface is more uniform.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. A cooling structure of a laminated plate with a slit rib for a combustion chamber of a turbofan engine is characterized by comprising an air film hole plate (6) and an impact hole plate (2), wherein the impact hole plate (2) and the air film hole plate (6) are arranged in parallel, an impact airflow cooling channel (3) is arranged between the air film hole plate (6) and the impact hole plate (2), and the air film hole plate (6), the impact hole plate (2) and the impact airflow cooling channel (3) form a double-layer wall structure of a lining in the combustion chamber of the turbofan engine;
a plurality of annular fins (4) with high blocking ratio are arranged on the surface of the air film pore plate (6) in the impinging air flow cooling channel (3) along the air flow direction, the annular fins (4) with high blocking ratio are parallel to each other, at least two contraction or expansion slits (41) for improving the heat exchange uniformity are arranged on the annular fins (4) with high blocking ratio along the cooling air flow direction, and the at least two contraction or expansion slits (41) are arranged on the annular fins (4) with high blocking ratio at intervals;
the cooling air flow enters the slot from the slot inlet (42) of the contraction or expansion slot (41) and flows out from the slot outlet (43), and when the slot inlet (42) of the contraction or expansion slot (41) is higher than the slot outlet (43), the contraction or expansion slot (41) is a contraction slot; when the height of the slit inlet (42) is lower than that of the slit outlet (43), the contraction or expansion slit (41) is an expansion slit; the upper and lower slit surfaces of the contraction or expansion slit (41) are arranged in an inclined way at a contraction or expansion angle;
strike orifice plate (2) on be equipped with and strike hole (1) air film orifice plate (6) on be equipped with air film hole (5), the aperture that strikes hole (1) and air film hole (5) is aperture d, follows on the cooling air current direction, high jam is located behind air film hole (5) than annular fin (4), and high jam is 1 ~ 5d than the distance between annular fin (4) and air film hole (5).
2. The structure for cooling the combustion chamber of the turbofan engine according to claim 1 wherein the impingement orifice plate (2) is an inlet plate disposed on the cold side of the combustion chamber; the gas film pore plate (6) is a gas outlet plate, and the gas film pore plate (6) is arranged on the gas side of the combustion chamber; the thickness of the impact pore plate (2) and the thickness of the air film pore plate (6) are both 0.5-3 d, and the width in the spreading direction is both 4-8 d.
3. The cooling structure of the rib plate with the slit for the combustion chamber of the turbofan engine according to claim 1, wherein the impingement hole plate (2) is provided with impingement holes (1) at uniform intervals, the film hole plate (6) is provided with film holes (5) at uniform intervals, the film holes (5) and the impingement holes (1) are arranged in a staggered manner, and the staggered spacing between the impingement holes (1) and the film holes (5) is 2-4 d.
4. The cooling structure of the rib plate with the slit for the combustion chamber of the turbofan engine according to claim 1, wherein the impingement holes (1) and the film holes (5) are respectively arranged on the impingement hole plate (2) and the film hole plate (6) in a direction perpendicular to a main air flow, the hole diameters d of the impingement holes (1) and the film holes (5) are 2-10 mm, and the relative distances between adjacent impingement holes (1) and adjacent film holes (5) along the air flow direction and the span direction are 4-8 d.
5. The structure for cooling a combustion chamber of a turbofan engine according to claim 4 wherein the impingement holes (1) and the film holes (5) are cylindrical holes.
6. The structure of cooling a slot-ribbed plate for a turbofan engine combustor according to claim 1, wherein the cross-sectional shape of the high blockage ratio annular rib (4) is square, and the ratio of the height e of the high blockage ratio annular rib (4) to the height H of the impingement airflow cooling channel (3) is 0.2 to 0.5.
7. The structure of cooling a slotted rib plate for a turbofan engine combustor according to claim 1 wherein the cross-sectional shape of the high blockage ratio annular rib (4) is square, the ratio of the height e of the high blockage ratio annular rib (4) to the height c of the contraction or expansion slit (41) is 0.2 to 0.5, and the penetration ratio β of the contraction or expansion slit (41) is:
in the formula C1Is the height of the slit entrance (42), C2Is the height of the slit outlet (43).
8. The turbofan engine combustor slotted rib plate cooling structure according to any of claims 1-7 wherein the ratio of the height H of the impingement air flow cooling channel (3) to the aperture diameter d is 0.5-3.
9. The structure of the slot-ribbed plate for the combustion chamber of turbofan engine according to any one of claims 1-7 wherein the contraction or expansion slits (41) are evenly spaced on the high blockage ratio annular rib (4), the contraction or expansion slits (41) and the rib solid portion 1:1 being arranged to ensure structural support.
10. The cooling method of a cooling structure of a slit-ribbed deck for a turbofan engine combustor according to claims 1-9, comprising the steps of:
the cooling airflow carries out impact heat exchange on the inner wall surface of the air film pore plate (6) through the impact holes (1), the cooling airflow impacting the air film pore plate (6) diffuses around to form wall surface jet flow (A), and then cross flow (B) is formed along the direction of the cold air flow; at the moment, the annular rib (4) with high blockage ratio blocks the cooling airflow, and the cross flow (B) interacts with the descending separation flow (C) formed on the upper surface of the annular rib (4) with high blockage ratio to form a large reflux area (D);
when the contraction or expansion slit (41) is an expansion slit, partial cooling air flow in the impingement air flow cooling channel (3) is sprayed out from the expansion slit to interact with the large reflux area (D), and an angular vortex (E) with opposite rotation direction is formed at the outlet of the expansion slit, namely, a low-speed secondary flow area immediately behind the high blockage ratio annular fin (4) is reduced, so that the heat exchange characteristic of a near-rib area is improved; meanwhile, the existing angle vortex (E) reduces the size of the large reflux area (D) and moves to the downstream of the annular rib (4) with high blocking ratio, so that the range of the area with high heat exchange coefficient is weakened, and the convection heat exchange coefficient impacting the target surface is distributed more uniformly;
when the contraction or expansion slit (41) is a contraction slit, part of cooling air flow in the impingement air flow cooling channel (3) is ejected from the contraction slit to interact with the large reflux area (D), a first angular vortex (F) with opposite rotation direction is formed at the outlet of the expansion slit, meanwhile, the separation flow (C) also interacts with the large reflux area (D), a second angular vortex (G) with the same rotation direction is formed at the downstream of the upper surface of the annular rib (4) with the high blockage ratio, namely, a low-speed secondary flow area immediately behind the annular rib (4) with the high blockage ratio is reduced, and therefore the heat exchange characteristic of a near rib area is improved; meanwhile, due to the existence of the first angular vortex (F) and the second angular vortex (G), the size of the large reflux area (C) is reduced and the large reflux area (C) moves to the downstream of the annular rib (4) with high blockage ratio, so that the range of the high heat exchange coefficient area is weakened, and the convection heat exchange coefficient of the impact target surface is distributed more uniformly;
and finally, part of cooling air flow enters the air film hole (5) to continue to carry out convective heat transfer, and then is blown to the outer wall surface of the air film hole (5) to form an air film, so that the high-temperature gas is prevented from ablating the air film hole plate (6), and the other part of cooling air flow is discharged from the outlet of the combustion chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111606243.6A CN114412645B (en) | 2021-12-26 | 2021-12-26 | Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111606243.6A CN114412645B (en) | 2021-12-26 | 2021-12-26 | Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114412645A true CN114412645A (en) | 2022-04-29 |
| CN114412645B CN114412645B (en) | 2023-01-31 |
Family
ID=81270253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111606243.6A Active CN114412645B (en) | 2021-12-26 | 2021-12-26 | Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114412645B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115013841A (en) * | 2022-05-12 | 2022-09-06 | 中国航发四川燃气涡轮研究院 | Afterburner double-layer floating sealing circular-square heat shield structure and rear exhaust system |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11347667A (en) * | 1998-06-08 | 1999-12-21 | Nakamura Seisakusho Kk | Heat radiator, and its forming method |
| JP2011208624A (en) * | 2010-03-31 | 2011-10-20 | Hitachi Ltd | Cooling structure for high-temperature member |
| CN103398398A (en) * | 2013-08-12 | 2013-11-20 | 北京华清燃气轮机与煤气化联合循环工程技术有限公司 | Double-seal connection structure of flame tube and transition section of combustion gas turbine combustion chamber |
| CN203687097U (en) * | 2013-12-24 | 2014-07-02 | 中航商用航空发动机有限责任公司 | Impact divergence turbulent flow cooling flame tube and combustion chamber |
| CN103968418A (en) * | 2014-05-26 | 2014-08-06 | 西北工业大学 | Double-layer-wall heat insulation screen used for afterburner |
| US20180003062A1 (en) * | 2016-07-04 | 2018-01-04 | Doosan Heavy Industries Construction Co., Ltd. | Gas turbine blade |
| CN109707532A (en) * | 2018-12-12 | 2019-05-03 | 中国航空工业集团公司西安飞机设计研究所 | A kind of bridging type active cooling structure |
| EP3537047A1 (en) * | 2018-03-07 | 2019-09-11 | United Technologies Corporation | Slot arrangements for an impingement floatwall film cooling of a turbine engine |
| US20200033003A1 (en) * | 2018-07-25 | 2020-01-30 | Rolls-Royce Deutschland Ltd & Co Kg | Combustion chamber assembly with a flow guiding device comprising a wall element |
| CN211715181U (en) * | 2020-03-18 | 2020-10-20 | 厦门大学 | Laminate cooling structure with slotted circular turbulence column |
| CN113107610A (en) * | 2021-04-13 | 2021-07-13 | 西北工业大学 | Through seam type semi-split seam trailing edge cooling structure and turbine blade |
-
2021
- 2021-12-26 CN CN202111606243.6A patent/CN114412645B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11347667A (en) * | 1998-06-08 | 1999-12-21 | Nakamura Seisakusho Kk | Heat radiator, and its forming method |
| JP2011208624A (en) * | 2010-03-31 | 2011-10-20 | Hitachi Ltd | Cooling structure for high-temperature member |
| CN103398398A (en) * | 2013-08-12 | 2013-11-20 | 北京华清燃气轮机与煤气化联合循环工程技术有限公司 | Double-seal connection structure of flame tube and transition section of combustion gas turbine combustion chamber |
| CN203687097U (en) * | 2013-12-24 | 2014-07-02 | 中航商用航空发动机有限责任公司 | Impact divergence turbulent flow cooling flame tube and combustion chamber |
| CN103968418A (en) * | 2014-05-26 | 2014-08-06 | 西北工业大学 | Double-layer-wall heat insulation screen used for afterburner |
| US20180003062A1 (en) * | 2016-07-04 | 2018-01-04 | Doosan Heavy Industries Construction Co., Ltd. | Gas turbine blade |
| EP3537047A1 (en) * | 2018-03-07 | 2019-09-11 | United Technologies Corporation | Slot arrangements for an impingement floatwall film cooling of a turbine engine |
| US20200033003A1 (en) * | 2018-07-25 | 2020-01-30 | Rolls-Royce Deutschland Ltd & Co Kg | Combustion chamber assembly with a flow guiding device comprising a wall element |
| CN109707532A (en) * | 2018-12-12 | 2019-05-03 | 中国航空工业集团公司西安飞机设计研究所 | A kind of bridging type active cooling structure |
| CN211715181U (en) * | 2020-03-18 | 2020-10-20 | 厦门大学 | Laminate cooling structure with slotted circular turbulence column |
| CN113107610A (en) * | 2021-04-13 | 2021-07-13 | 西北工业大学 | Through seam type semi-split seam trailing edge cooling structure and turbine blade |
Non-Patent Citations (2)
| Title |
|---|
| 刘存良等: "收缩-扩张形气膜孔提高气膜冷却效率的机理研究", 《航空动力学报》 * |
| 王建儒等: "燃烧室对接狭缝设计参数对压强振荡的影响研究", 《固体火箭技术》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115013841A (en) * | 2022-05-12 | 2022-09-06 | 中国航发四川燃气涡轮研究院 | Afterburner double-layer floating sealing circular-square heat shield structure and rear exhaust system |
| CN115013841B (en) * | 2022-05-12 | 2023-10-31 | 中国航发四川燃气涡轮研究院 | Afterburner double-layer floating seal round-to-square heat shield structure and rear exhaust system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114412645B (en) | 2023-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7886541B2 (en) | Wall elements for gas turbine engine combustors | |
| CN108223022B (en) | Turbulent flow structure in array jet cooling | |
| CN107503801A (en) | A kind of efficiently array jetting cooling structure | |
| CN113374536B (en) | Gas turbine guide vane | |
| CN110185554A (en) | A kind of double wall cooling structure for jet engine vector spray | |
| CN114412645B (en) | Cooling structure and cooling method of laminated plate with slit ribs for turbofan engine combustion chamber | |
| CN112682108A (en) | Turbine blade end wall structure with D-shaped micro-group air film cooling holes, method of turbine blade end wall structure and gas turbine | |
| CN114109515B (en) | Turbine blade suction side cooling structure | |
| CN110107914A (en) | One kind being based on the impact-gaseous film control structure of triangular-section deflector (ring) | |
| CN216642214U (en) | High-blockage-ratio finned laminate cooling structure for middle chord area of turbine blade | |
| CN114109514A (en) | Turbine blade pressure surface cooling structure | |
| CN114382553B (en) | High-blockage-ratio rib laminate cooling structure and cooling method for middle chord zone of turbine blade | |
| CN115898693A (en) | Corrugated turbulent flow plane cooling device and application | |
| CN115790245A (en) | Corrugated plate cooling device and application | |
| CN114109518A (en) | Turbine blade leading edge ribbed rotational flow-air film composite cooling structure | |
| CN108386234A (en) | It is a kind of to arrange the combustion engine blade interior cooling structure that fin is basic cooling unit with column | |
| CN218117856U (en) | Blade of gas turbine | |
| CN112577069A (en) | Oblique flow combustion chamber side wall surface structure suitable for small head inclination angle | |
| CN117662251A (en) | Air film hole structure of engine cooling wall surface and air film forming method | |
| CN114771846A (en) | Cooling device for air film and internal turbulent flow and application | |
| CN114776471A (en) | Double-wall impact cooling device and application | |
| RU197365U1 (en) | FILM COOLED GAS TURBINE ELEMENT | |
| CN115898707A (en) | Baffling cooling device and application | |
| US11952913B2 (en) | Turbine blade with improved swirl cooling performance at leading edge and engine | |
| CN113374545A (en) | Impingement cooling structure based on array annular raised target plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |