A slotted delta winglet vortex generator for enhancing overall heat transfer performance

Abstract

The present invention relates to a slotted triangular winglet pair of vortex generators for enhancing overall heat exchange performance, belonging to the field of enhanced heat exchange technology. The slotted triangular winglet pair of vortex generators is installed in the cooling channel of a high-temperature component, with multiple pairs of slotted triangular winglet pairs of vortex generators evenly distributed along the length of the bottom wall of the cooling channel along the direction of fluid flow. The slotted triangular winglet pair of vortex generators includes two mirror-image slotted triangular winglets, each having a slotted structure on its plate surface along the direction of fluid flow. By installing the slotted triangular winglet pair of vortex generators in the cooling channel, the present invention increases the heat exchange area within the channel, enhances the disturbance effect on the fluid, and significantly improves the convective heat exchange performance of the channel.

Description

Technical Field

[0001] The present invention belongs to the technical field of enhanced heat exchange, and in particular relates to a slotted triangular winglet vortex generator for enhancing overall heat exchange performance. Background Art

[0002] Convective heat exchange enhancement technology is mainly divided into passive heat exchange enhancement technology and active heat exchange enhancement technology. Passive heat exchange enhancement technology has been widely studied and applied because it does not require additional power and can save energy.

[0003] Vortex generators are a common heat transfer enhancement structure used within internal cooling channels. They are widely used in solar air heaters, internal cooling of gas turbine blades, and heat transfer applications such as combustion chambers and electronic equipment. To generate clean, renewable energy, solar power generation technology has been extensively researched. Solar air heaters are key to converting thermal energy into mechanical energy, which can then be converted into electrical energy. However, the low thermal conductivity of air results in a low convective heat transfer coefficient. Therefore, enhancing the heat transfer between air and solar absorbers is an important approach to improving the performance of solar air heaters. The rising inlet temperatures of gas turbine turbines have far exceeded the temperature limits of turbine blade materials, making the development of efficient turbine blade cooling technologies imperative to reduce blade temperatures and extend service life. Due to the increased Mach number and cruise time of hypersonic vehicles, scramjet engines face a very harsh thermal environment. Regenerative cooling is considered the optimal cooling method for scramjet engines, and the development of efficient regenerative cooling systems has become a key scientific and technological challenge for scramjet engines. In addition, in modern high-power aerospace precision instruments, high-intensity lasers and other equipment, electronic components are developing towards high integration and miniaturization, which causes the heat generation power of the devices to continue to rise. The heat dissipation performance of electronic components has become one of the bottlenecks restricting the development of the microelectronics industry.

[0004] The use of triangular winglets as vortex generators in existing technologies can generate counter-rotating vortex pairs within internal channels, creating fluid disturbances that enhance convective heat transfer and increase heat exchange area, thereby enhancing channel heat transfer performance. Slotted triangular winglet pairs have been widely studied for their ability to reduce pressure loss in continuous fin channels. However, the placement of triangular winglet vortex generators increases channel flow resistance, leading to increased pressure loss within the channel. Summary of the Invention

[0005] Technical issues to be solved:

[0006] In order to avoid the shortcomings of the prior art, the present invention provides a slotted triangular winglet-pair vortex generator that enhances the overall heat exchange performance. By installing the slotted triangular winglet-pair vortex generator in an internal cooling channel, the local heat exchange performance of the wing rear area of ​​the triangular winglet-pair vortex generator in the internal cooling channel is effectively enhanced, and the pressure loss at the inlet and outlet of the channel is effectively reduced, thereby improving the overall heat exchange performance of the channel.

[0007] The technical solution of the present invention is: a pair of slotted triangular winglets with vortex generators that enhance overall heat exchange performance is arranged in the cooling channel of a high-temperature component; along the direction of fluid flow, multiple pairs of slotted triangular winglets with vortex generators are evenly distributed along the length of the bottom wall of the cooling channel;

[0008] The slotted triangular winglet pair vortex generator comprises two mirror-image slotted triangular winglets, and a slotted structure is provided on the plate surface of the triangular winglet along the fluid flow direction.

[0009] A further technical solution of the present invention is that a single row or multiple rows of slotted triangular winglet vortex generators are provided in the cooling channel.

[0010] A further technical solution of the present invention is: the spacing between the two slotted triangular winglets in the vortex generator is s; along the fluid flow direction, the spacing between two adjacent rows of triangular winglets in the vortex generator is P, and the ratio of the two is 1 / 10≤s / P≤2 / 5.

[0011] A further technical solution of the present invention is: the height of the slotted triangular winglet relative to the vortex generator is hv, the height of the cooling channel is H, and the ratio of the two is 1 / 3≤hv / H≤2 / 3.

[0012] A further technical solution of the present invention is: the length of the slotted triangular winglet is lv, and the ratio of the length of the slotted triangular winglet to the height hv of the vortex generator is 1 / 2≤lv / hv≤2.

[0013] A further technical solution of the present invention is: a rectangular slot is opened on the plate surface of the slotted triangular winglet; the long side of the rectangular slot is parallel to the fluid flow direction, and its length is ls, and its ratio to the length lv of the slotted triangular winglet is 1 / 4≤ls / lv≤1 / 2.

[0014] A further technical solution of the present invention is: the ratio of the height of the rectangular slot hs to the height hv of the slotted triangular winglet to the vortex generator is 1 / 20≤hs / hv≤1 / 10.

[0015] A further technical solution of the present invention is: the distance between the bottom long side of the rectangular slot and the bottom edge of the slotted triangular winglet is d, the height of the slotted triangular winglet vortex generator is hv, and the ratio of the height hv of the slotted triangular winglet to the vortex generator is 1 / 4≤hs / hv≤1 / 2.

[0016] A further technical solution of the present invention is: the slotted triangular winglet is a right triangle, one side of which is perpendicular to the base, and the right-angled sides of two slotted triangular winglets in the same slotted triangular winglet vortex generator are adjacent, and the distance is s.

[0017] A further technical solution of the present invention is that the state of the fluid in the cooling passage is laminar flow or turbulent flow.

[0018] Beneficial effects

[0019] The beneficial effect of the present invention is that, compared with a smooth channel, by installing a slit triangular winglet vortex generator in the cooling channel, the heat exchange area in the channel is increased, the disturbing effect on the fluid is increased, and the convective heat transfer performance of the channel is greatly improved.

[0020] Compared to conventional channels equipped with delta winglet pairs, slotted delta winglet pairs do not significantly increase the channel's heat transfer area. However, by creating narrow slots with specific parameters within specific areas of the delta winglet pairs in high-blockage channels, they first allow some fluid to pass directly through the delta winglet pairs, reducing flow separation caused by the presence of the vortex generators. This reduced flow separation can reduce pressure loss within the channel. Secondly, when the slot geometric parameters are specific, secondary vortices can be induced behind the delta winglet pairs to mix the main flow. Furthermore, by creating slots at specific distances from the delta winglets, the counter-vortex pairs induced by the delta winglet pairs are brought closer to the bottom surface. This enhances mixing between the main flow and the boundary layer fluid, improving the channel's heat transfer performance. Furthermore, as the Reynolds number increases, the slotted delta winglet pairs improve the high pressure loss disadvantage of delta winglet pairs compared to unslotted delta winglet pairs, resulting in better overall heat transfer performance.

[0021] Therefore, the present invention is a slotted triangular winglet vortex generator structure suitable for enhancing overall thermal performance, which has the advantages of high convection heat transfer performance and high overall thermal performance. The improvements in heat transfer performance, pressure loss and overall thermal performance can be seen in the drawings of the specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention after removing the top wall.

[0023] Figure 2 This is a top view of an embodiment of the present invention with the top wall removed.

[0024] Figure 3 This is a right view of the embodiment of the present invention after removing the right wall.

[0025] Figure 4 This is the vortex generator channel of a common delta winglet for comparison with the present invention.

[0026] Figure 5 Heat exchange performance (Nu / Nu0), pressure loss (f / f0) and overall thermal performance (Nu / Nu0 / (f / f0)) of the embodiment of the present invention 1 / 3 ) and Example 0 (ordinary delta winglet vortex generator channel) are compared with the heat transfer performance, pressure loss and overall thermal performance as the Reynolds number varies in the range of 20,000 to 80,000.

[0027] Explanation of reference numerals: 1. Left wall; 2. Right wall, 3. Bottom wall, 4. Slotted triangular winglet vortex generator, W. Width of cooling channel, H. Height of cooling channel, P. Spacing between two adjacent rows of triangular winglet vortex generators, s. Spacing between a row of triangular winglet vortex generators, a. Angle between triangular winglet vortex generators and the incoming flow direction, l v . Length of the delta winglet vortex generator, l s . Length of the slit, h v .Height of the delta winglet vortex generator, h s .The height of the slit, t.The thickness of the slit delta winglet. DETAILED DESCRIPTION

[0028] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] The present invention provides a slotted triangular winglet vortex generator channel for enhancing overall thermal performance. The invention comprises a left wall 1, a right wall 2, a bottom wall 3, a truncated rib 4, and a slotted triangular winglet vortex generator. The slotted triangular winglet vortex generator is placed in a cooling channel of an internally cooled component such as a blade with a width W and a height H. The height of the triangular winglet is h.v , length is l v， The vortex generators are arranged in a row along the incoming airflow direction, with a spacing of P between every two adjacent rows of triangular winglets. The angle of attack of the slotted triangular winglets installed in the internal cooling channel to the vortex generators can be various angles.

[0031] Figures 1 to 3 This is an embodiment of the present invention. In this embodiment, five pairs of slotted triangular winglet vortex generators are arranged in the cooling channel, wherein the slotted triangular winglet vortex generators are placed at the center of the bottom of the rectangular channel, the distance between the slotted triangular winglet and the center line of the rectangular channel bottom is S / 2, the spacing between a pair of slotted triangular winglets is S, and the height, length and thickness of the slotted triangular winglet are l v 、h s and t. Height h of the slotted delta winglet v is 1 / 2 of the height H of the rectangular channel, and the length l of the slotted triangular winglet v is the height h of the slotted delta winglet v The length of the slit on the delta winglet is l s is the height of the slotted delta winglet h v 1 / 2 of the height of the slot on the triangular winglet h s is the height of the slotted delta winglet h v 1 / 10 of the total volume. When the fluid flows through the slotted triangular winglet pair vortex generator, most of the fluid undergoes flow separation and generates a pair of longitudinal reverse vortex pairs. The existence of the reverse vortex pairs allows the fluid to be well mixed. When a small portion of the fluid flows through the slotted triangular winglet pair, the flow separation of the fluid is reduced due to the slots, thereby reducing the pressure loss of the channel. In addition, due to the slots, transverse vortices are generated, which brings the reverse vortex pairs closer to the boundary layer of the bottom surface, increasing the heat and mass transfer of the boundary layer fluid, so as to improve the overall thermal performance of the channel. The calculation results of the embodiment show that when the Reynolds number of the cold fluid is 80,000, the overall thermal performance of the embodiment is improved by 5% compared with that of the ordinary triangular winglet pair vortex generator channel, and this improvement in overall thermal performance increases with the increase of the Reynolds number.

[0032] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A slotted delta winglet vortex generator for enhancing overall heat exchange performance, arranged in the cooling channel of a high-temperature component; characterized by: Along the fluid flow direction, multiple pairs of slotted triangular winglets and vortex generators are evenly distributed along the length of the bottom wall of the cooling channel; The slotted triangular winglet pair vortex generator comprises two mirror-image slotted triangular winglets, and a slotted structure is provided on the plate surface of the triangular winglet along the fluid flow direction; The height of the slotted triangular winglet relative to the vortex generator is hv, and the height of the cooling channel is H, and the ratio of the two is 1 / 3≤hv / H≤2 / 3; the length of the slotted triangular winglet is lv, and the ratio of the height of the slotted triangular winglet relative to the vortex generator hv is 1 / 2≤lv / hv≤2; a rectangular slot is provided on the plate surface of the slotted triangular winglet; the long side of the rectangular slot is parallel to the fluid flow direction, and its length is ls, and the ratio of the length of the slotted triangular winglet relative to the length lv is 1 / 4≤ls / lv ≤1 / 2; the height of the rectangular slot is hs, and the ratio of the height of the slotted triangular winglet relative to the vortex generator hv is 1 / 20≤hs / hv≤1 / 10; the distance between the bottom long side of the rectangular slot and the bottom edge of the slotted triangular winglet is d, the height of the slotted triangular winglet vortex generator is hv, and the ratio of the height of the slotted triangular winglet relative to the vortex generator hv is 1 / 4≤d / hv≤1 / 2.

2. The slotted delta winglet vortex generator for enhancing overall heat exchange performance according to claim 1, characterized in that: A single row or multiple rows of slotted delta winglet vortex generators are arranged in the cooling channel.

3. The slotted delta winglet vortex generator for enhancing overall heat exchange performance according to claim 1, characterized in that: The spacing between the two slotted triangular winglets in the vortex generator is s; along the fluid flow direction, the spacing between two adjacent rows of triangular winglets in the vortex generator is P, and the ratio of the two is 1 / 10 ≤ s / P ≤ 2 / 5.

4. The slotted delta winglet vortex generator for enhancing overall heat exchange performance according to claim 1, characterized in that: The slotted triangular winglet is a right triangle, one side of which is perpendicular to the base, and the right-angled sides of two slotted triangular winglets in the same slotted triangular winglet vortex generator are adjacent, with a distance s.

5. The slotted delta winglet vortex generator for enhancing overall heat exchange performance according to claim 1, characterized in that: The fluid state in the cooling passage is laminar flow or turbulent flow.

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