A stator blade profile and design method for suppressing low Reynolds number effects in a double-slotted compressor

Abstract

This invention relates to the field of compressor technology and discloses a double-slotted compressor stator airfoil and its design method for suppressing low Reynolds number effects. The stator airfoil employs a three-section design comprising a leading section, a middle section, and a trailing section. The leading and middle sections are separated by a forward jet slot penetrating the pressure and suction surfaces of the blade, while the middle and trailing sections are separated by a backward jet slot penetrating the pressure and suction surfaces. Both the forward and backward jet slots are tapered channels formed by a left and right circular arc. Under low Reynolds number conditions, when the airflow passes through the double-slotted compressor stator airfoil, the high-pressure airflow on the pressure surface accelerates towards the suction surface through the forward and backward jet slots, forming two jets. This progressively increases the boundary layer kinetic energy of the suction surface in two stages, thereby weakening flow separation. Furthermore, the double-slotted compressor stator airfoil of this invention effectively suppresses laminar separation, thereby reducing airfoil losses.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and discloses a stator vane profile and design method for a double-slotted compressor used to suppress low Reynolds number effects. Background Technology

[0002] When an aero-engine enters the high-altitude region, the compressor Reynolds number drops significantly. Under the influence of the adverse pressure gradient, the laminar flow on the blade surface is prone to closed-loop separation or even large-scale open-loop separation, causing severe channel blockage and a significant increase in total pressure loss. This leads to degradation of the compressor's aerodynamic performance and a reduction in its stable operating range. The low Reynolds number effect is the core challenge affecting the stable operation of compressors in the high-altitude region, and the control and elimination of laminar separation are key to suppressing the low Reynolds number effect in compressors.

[0003] Blade slotting is a traditional passive control technology for compressor flow separation. By machining slots or gaps in the blade to connect the pressure and suction surfaces, a small amount of airflow is directed from the pressure surface to re-accelerate the boundary layer flow on the suction surface and blow away the low-energy flow in the three-dimensional end region, thereby suppressing flow separation on the suction surface. This technology is mainly used for modern high-load, large-angle compressor blades. The slotting position is generally 10% of the span height in the end region of the compressor blade, and the target is end-region flow separation. If it is directly introduced into the design of low Reynolds number compressor blades, there are two problems: (1) The separation caused by the low Reynolds number effect exists in both the end region and the mainstream region, covering the entire blade height along the span, and conventional end-region slotting is difficult to control the global flow; (2) Under low Reynolds number conditions, there is a large-scale open separation on the compressor suction surface, and the energy introduced by a single slot jet is insufficient to suppress the large-scale flow separation. Summary of the Invention

[0004] The purpose of this invention is to provide a stator airfoil profile and design method for a double-slotted compressor to suppress the low Reynolds number effect, which can effectively suppress laminar separation and reduce airfoil losses under low Reynolds number conditions.

[0005] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0006] A double-slotted compressor stator airfoil for suppressing low Reynolds number effects includes an airfoil body, a front jet slot, and a rear jet slot. The front and rear jet slots are both located in the middle of the airfoil body and extend from the pressure surface to the suction surface, dividing the airfoil body into a front section, a middle section, and a rear section. The front and rear jet slots are used to guide the high-pressure airflow from the pressure surface of the airfoil body to accelerate towards the suction surface, thereby increasing the boundary layer kinetic energy of the suction surface and weakening laminar separation.

[0007] Furthermore, the intersection of the left boundary of the front jet slot and the suction surface profile of the airfoil body is located at the laminar separation initiation point on the suction surface profile.

[0008] A method for designing a double-slotted compressor stator blade profile to suppress low Reynolds number effects, used to prepare the double-slotted compressor stator blade profile as described above, comprising:

[0009] Based on the initial airfoil, determine the left and right opening positions of the front and rear jet slots;

[0010] Determine the left and right boundaries of the front jet slot and the rear jet slot;

[0011] The stator blades of a double-slotted compressor are cut to form the front jet slot and the rear jet slot.

[0012] Furthermore, the steps for determining the left and right slit locations of the front jet slit include:

[0013] On the plane containing the blade body, with the leading edge of the blade body as the origin, and the direction from the leading edge to the trailing edge as... The positive direction of the axis, perpendicular to The axis and the direction pointing towards the suction surface are Establish a two-dimensional rectangular coordinate system along the positive axis;

[0014] CFD simulation of the airfoil body under low Reynolds number conditions was performed, and the laminar separation starting point on the suction surface profile was selected as point A1, the opening position of the suction surface on the left side of the front jet slot.

[0015] The intersection of the first auxiliary line passing through point A1 and the initial blade pressure surface profile is taken as point A2, the opening position of the pressure surface on the left side of the front jet slit. The first auxiliary line and the first tangent line passing through point A1 on the initial blade suction surface profile have a first preset angle.

[0016] Draw a normal line to the pressure surface profile of the blade body through point A1. Take a first auxiliary point at a first preset distance from point A1 on the normal line. The intersection of the fourth auxiliary line passing through the first auxiliary point and the suction surface profile of the blade body is taken as the opening position B1 of the suction surface on the right side of the front jet slot. The intersection of the fourth auxiliary line and the pressure surface profile of the blade body is taken as the opening position B2 of the pressure surface on the right side of the front jet slot. The fourth auxiliary line and the line A1-A2 form a third preset angle.

[0017] Furthermore, the steps for determining the left and right slit locations of the rear jet slit include:

[0018] By analyzing point A1, the opening position of the suction surface on the left side of the front jet slot. Using the axial coordinates, the Reynolds number of the double-slotted compressor stator airfoil under design conditions, and the axial chord length of the airfoil body, the position C1 of the slot opening on the suction surface to the left of the rear jet slot is obtained. Axial coordinates; with the airfoil's suction surface profile line intersecting point C1. The point with the same axis coordinates is point C1, which is the opening position of the suction surface on the left side of the rear jet slot.

[0019] The intersection of the third auxiliary line passing through point C1 and the pressure surface profile of the blade body is taken as the opening position C2 of the pressure surface on the left side of the rear jet slot. The third auxiliary line has a second preset angle with the second tangent line passing through point C1 on the initial suction surface profile of the blade.

[0020] Draw the normal to the pressure surface profile of the airfoil body through point C1. Take a second auxiliary point at a second preset distance from point C1 on the normal. The intersection of the fifth auxiliary line passing through the second auxiliary point and the initial airfoil suction surface profile is the opening position D1 of the suction surface on the right side of the rear jet slot. The intersection of the fifth auxiliary line and the initial airfoil pressure surface profile is the opening position D2 of the pressure surface on the right side of the rear jet slot. The fifth auxiliary line and the line C1-C2 form a fourth preset angle.

[0021] Furthermore, the opening position C1 on the suction surface on the left side of the rear jet slit... The formula for calculating axis coordinates is:

[0022] ;

[0023] in, The location of the slit opening on the suction surface on the left side of the rear jet slit is point C1. Axis coordinates The axial chord length of the airfoil body. Point A1 is the opening position of the suction surface on the left side of the front jet slot. Axis coordinates The Reynolds number of the stator blade profile of the double-slot compressor under design conditions. is the critical Reynolds number of the airfoil body.

[0024] Furthermore, the steps for determining the left and right boundaries of the front jet slot include:

[0025] With the intersection point O1 of the perpendicular bisector of line A1-A2 and the normal to the pressure surface profile line passing through point A2 as the center, and the arc passing through points A1 and A2... As the left boundary of the front jet slot;

[0026] An arc passing through points B1 and B2 is centered at point O3, the intersection of the perpendicular bisector of line B1-B2 and the normal to the suction surface profile passing through point B1. This is the right boundary of the front jet slot.

[0027] Furthermore, the steps for determining the left and right boundaries of the rear jet slot include:

[0028] An arc passing through points C1 and C2 is drawn with its center at point O2, where the perpendicular bisector of line C1-C2 intersects the normal to the pressure surface profile at point C2. This is the left boundary of the rear jet slot;

[0029] An arc passing through points D1 and D2 is centered at point O4, the intersection of the perpendicular bisector of line D1-D2 and the normal to the suction surface profile passing through point D1. This is the right boundary of the rear jet slot.

[0030] Furthermore, the step of cutting and forming the stator blade profile of the double-slotted compressor having the front jet slot (4) and the rear jet slot (5) includes:

[0031] The arc Line segment A1B1, arc The area enclosed by line segment B2A2 is the body to be cut in the front jet seam, and the arc... Line segment C1D1, arc The area enclosed by line segment D2C2 is the rear jet slot cut-off body. The front jet slot cut-off body and the rear jet slot cut-off body are cut off from the blade body to form the front section, middle section, and rear section of the blade. Then, the leading edge radius of the middle section and the rear section of the blade is rounded off by selecting the same leading edge radius as the blade body. The trailing edge radius of the front section and the middle section of the blade is rounded off by selecting the same trailing edge radius as the blade body to form a double-slotted compressor stator blade with the aforementioned front jet slot and rear jet slot.

[0032] Compared with the prior art, the beneficial effects of this invention are:

[0033] This invention employs a three-section double-slotted compressor stator airfoil comprising a front section, a middle section, and a rear section. The front and middle sections are separated by a front jet slot that penetrates both the pressure and suction surfaces of the blade, while the middle and rear sections are separated by a rear jet slot that also penetrates both the pressure and suction surfaces. Both the front and rear jet slots are tapered channels formed by a left and a right circular arc. Under low Reynolds number conditions, when the airflow passes through the double-slotted compressor stator airfoil, the high-pressure airflow on the pressure surface accelerates towards the suction surface through the front and rear jet slots, forming two jets. This gradually increases the kinetic energy of the suction surface boundary layer in two stages, thereby weakening flow separation. Moreover, the stator blade profile of the double-slotted compressor of the present invention has a lower critical Reynolds number compared with the existing blade profile. Under the condition that the actual Reynolds number is lower than the critical Reynolds number, the stator blade profile of the double-slotted compressor of the present invention can effectively suppress laminar flow separation compared with the existing blade profile, thereby reducing blade loss. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the stator vane configuration of a double-slotted compressor used to suppress the low Reynolds number effect in the embodiment.

[0035] Figure 2This is a flowchart illustrating the design method for the stationary vane profile of a double-slotted compressor used to suppress the low Reynolds number effect in the embodiments.

[0036] Figure 3 This is a schematic diagram of the initial blade shape in the embodiment;

[0037] Figure 4 This is a schematic diagram illustrating the determination of the left-side opening positions A1 and A2 of the front jet slit and the left-side opening positions C1 and C2 of the rear jet slit in the embodiment.

[0038] Figure 5 This is a schematic diagram illustrating the determination of the right-side opening positions B1 and B2 of the front jet slit and the right-side opening positions D1 and D2 of the rear jet slit in the embodiment.

[0039] Figure 6 The left boundary arc of the front jet slot is determined in the embodiment. Determine the left boundary arc of the jet slit. A schematic diagram;

[0040] Figure 7 The right boundary arc of the front jet slot is determined in the embodiment. Determine the right boundary arc of the jet slit. A schematic diagram;

[0041] Figure 8 This is a schematic diagram illustrating the cutting and rounding process in the embodiment.

[0042] Figure 9 This is a schematic diagram of the stator planar blade structure of the low Reynolds number double-slotted compressor after double-slotting in the embodiment;

[0043] Figure 10 This example compares the loss coefficients of the stator blade profile and the initial blade profile of the double-slotted compressor at different Reynolds numbers.

[0044] Figure 11 The Mach number flow field diagram for the initial airfoil is shown in the example under the condition of Reynolds number 4.7E5.

[0045] Figure 12 The Mach number flow field diagram of the stationary vane type of the double-slotted compressor is shown in the embodiment under the condition of Reynolds number 4.7E5.

[0046] Figure 13 The Mach number flow field diagram for the initial airfoil is shown in the example under the condition of Reynolds number 5.5E4.

[0047] Figure 14 The Mach number flow field diagram of the stationary vane type of the double-slotted compressor is shown in the embodiment under the condition of Reynolds number 5.5E4.

[0048] Among them, 1-front section of the blade, 2-middle section of the blade, 3-rear section of the blade, 4-front jet slot, 5-rear jet slot, and 6-blade body. Detailed Implementation

[0049] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0050] This invention provides a double-slotted compressor stator airfoil for suppressing low Reynolds number effects, comprising an airfoil body 6, a front jet slot 4, and a rear jet slot 5. The front jet slot 4 and the rear jet slot 5 are both located on the airfoil body 6 and extend from the pressure surface of the airfoil body 6 to the suction surface, dividing the airfoil body 6 into a front section 1, a middle section 2, and a rear section 3. The front jet slot 4 and the rear jet slot 5 are used to guide the high-pressure airflow from the pressure surface of the airfoil body 6 to accelerate towards the suction surface, thereby increasing the boundary layer kinetic energy of the suction surface and weakening laminar separation.

[0051] Based on the same inventive concept, this invention also provides a method for designing a double-slotted compressor stator blade profile to suppress low Reynolds number effects, for preparing the aforementioned double-slotted compressor stator blade profile, comprising:

[0052] Based on the blade body 6, determine the left and right opening positions of the front jet slot 4 and the rear jet slot 5;

[0053] Determine the left and right boundaries of the front jet slot 4 and the rear jet slot 5;

[0054] The compressor stator blades are cut to form a double-slotted compressor with the front jet slot 4 and the rear jet slot 5.

[0055] This invention employs a three-section double-slotted compressor stator airfoil comprising a front section 1, a middle section 2, and a rear section 3. The front section 1 and the middle section are separated by a front jet slit 4 that penetrates the pressure and suction surfaces of the blade, while the middle section 2 and the rear section 3 are separated by a rear jet slit 5 that penetrates the pressure and suction surfaces of the blade. Both the front jet slit 4 and the rear jet slit 5 are tapered channels formed by a left and a right circular arc. Under low Reynolds number conditions, when the airflow passes through the double-slotted compressor stator airfoil, the high-pressure airflow on the pressure surface is accelerated towards the suction surface through the front and rear jet slits, forming two jets. This gradually increases the kinetic energy of the suction surface boundary layer in two stages, thereby weakening flow separation. Moreover, the stator blade profile of the double-slotted compressor of the present invention has a lower critical Reynolds number compared with the existing blade profile. Under the condition that the actual Reynolds number is lower than the critical Reynolds number, the stator blade profile of the double-slotted compressor of the present invention can effectively suppress laminar flow separation compared with the existing blade profile, thereby reducing blade loss.

[0056] Example

[0057] See Figure 1 This embodiment provides a double-slotted compressor stator airfoil for suppressing low Reynolds number effects, including an airfoil body 6, a front jet slot 4, and a rear jet slot 5. Both the front jet slot 4 and the rear jet slot 5 are located in the middle of the airfoil body 6 and extend from the pressure surface to the suction surface, dividing the airfoil body 6 into a leading section 1, a middle section 2, and a trailing section 3. The intersection of the left boundary of the front jet slot 4 and the suction surface profile of the airfoil body 6 is located at the laminar separation initiation point on the suction surface profile. The front jet slot 4 and the rear jet slot 5 are used to guide the high-pressure airflow from the pressure surface of the airfoil body 6 to accelerate towards the suction surface, thereby increasing the boundary layer kinetic energy of the suction surface and weakening laminar separation.

[0058] Based on the same inventive concept, see [link to inventive concept] Figure 2 This embodiment also provides a method for designing a double-slotted compressor stator blade profile to suppress low Reynolds number effects, used to prepare the aforementioned double-slotted compressor stator blade profile, comprising the following steps:

[0059] Step 1: Based on existing blade design methods, complete the initial blade design to obtain the blade body 6 as the initial blade shape. The initial blade shape is as follows: Figure 3 As shown. Furthermore, on the plane containing the initial blade shape, with the leading edge of the initial blade shape as the origin, and the direction from the leading edge to the trailing edge as... The positive direction of the axis, perpendicular to The axis and the direction pointing towards the suction surface are Establish a two-dimensional rectangular coordinate system along the positive axis.

[0060] Step 2: Based on the initial airfoil, determine the left and right opening positions of the front jet slot 4 and the rear jet slot 5. The left opening position of the front jet slot 4 includes point A1 on the left suction side and point A2 on the left pressure side; the right opening position of the front jet slot 4 includes point B1 on the right suction side and point B2 on the right pressure side. The left opening position of the rear jet slot 5 includes point C1 on the left suction side and point C2 on the left pressure side; the right opening position of the rear jet slot 5 includes point D1 on the right suction side and point D2 on the right pressure side.

[0061] Step 21: See Figure 4 Determine the left opening positions A1 and A2 of the front jet slit 4.

[0062] First, CFD simulations were performed on the initial airfoil under low Reynolds number conditions. The laminar separation initiation point on the suction surface profile was selected as point A1, the opening position of the suction surface on the left side of the front jet slot 4, and the coordinates of point A1 were obtained. , ) and the critical Reynolds number of the initial airfoil The low Reynolds number condition refers to a Reynolds number of 1×10⁻⁶. 4 ~1×10 5 Operating conditions within the range.

[0063] Then, draw the first tangent to the initial blade suction surface profile at point A1, and simultaneously, along the chord-direction pointing outwards from the suction surface, draw the first auxiliary straight line at point A1. The first auxiliary straight line and the first tangent form a first preset angle. Select the intersection of the first auxiliary straight line and the initial blade pressure surface profile as point A2, the opening position of the pressure surface on the left side of the front jet slot 4, and obtain the coordinates of point A2. , The first preset included angle ranges from 18° to 22°.

[0064] Step 22: See Figure 4 After determining the left-side opening positions C1 and C2 of the jet slit 5, the following steps are taken.

[0065] First, by analyzing point A1, the opening position of the suction surface on the left side of the front jet slot 4. Using the axial coordinates, the Reynolds number of the double-slotted compressor stator airfoil under design conditions, and the axial chord length of the airfoil body 6, the opening position C1 of the suction surface on the left side of the rear jet slot 5 is obtained. Axis coordinates The opening position C1 on the suction surface of the left side of the rear jet slit 5. Axis coordinates The calculation formula is:

[0066] ;

[0067] in, The axial chord length of the initial airfoil. Point A1 is the opening position of the suction surface on the left side of the front jet slit 4. Axis coordinates The Reynolds number of the stator blade profile of the double-slot compressor under design conditions. The critical Reynolds number for the initial airfoil. In this embodiment, when determining the opening position C1 on the left side of the suction surface of the rear jet slot 5, the opening position A1 on the left side of the suction surface of the front jet slot 4 was also considered. Axis coordinates and the axial chord length of the initial airfoil This design ensures a reasonable gradient distribution of the front and rear jet slots 5 along their axial direction, achieving a synergistic jetting effect. It also prevents flow interference or energy loss due to improper slot placement, enhancing the overall flow control capability of the double-slotted structure. Furthermore, it considers the Reynolds number of the stator vane profile of the double-slotted compressor under design conditions. Critical Reynolds number of the initial airfoil It can optimize the axial position design of the rear jet slot 5 according to the actual flow state under the design conditions, improve the adaptability of the opening position of the rear jet slot 5 to the boundary layer development state, effectively suppress laminar separation of the suction surface, and improve the stable working range of the compressor.

[0068] Based on the opening position C1 of the suction surface on the left side of the rear jet slot 5 Axis coordinates In a two-dimensional rectangular coordinate system, along the initial airfoil suction surface profile... The axis coordinates are Let point C1 be the point. Determine point C1. Axis coordinates Then the coordinates of point C1 are ( , ).

[0069] Then, draw the second tangent to the initial blade suction surface profile at point C1, and simultaneously, along the chord-direction pointing outwards from the suction surface, draw the third auxiliary straight line at point C1. The third auxiliary straight line forms an angle of 18°~22° with the second tangent. Select the intersection of the third auxiliary straight line and the initial blade pressure surface profile as point C2, the opening position of the pressure surface on the left side of the rear jet slot 5, and obtain the coordinates of point C2. , ).

[0070] Step 23: See Figure 5 Determine the right-side opening positions B1 and B2 of the front jet slit 4.

[0071] First, draw the normal to the initial airfoil pressure surface profile through point A1, and then draw a line 50% away from point A1 on this normal. T max Take the first auxiliary point, and draw a fourth auxiliary line through the first auxiliary point that forms a third preset angle with the line A1-A2. Select the intersection of the fourth auxiliary line and the initial blade suction surface profile as point B1, the opening position of the suction surface on the right side of the front jet slot 4. Obtain the coordinates of point B1. , The intersection of the fourth auxiliary straight line and the initial airfoil pressure surface profile is selected as point B2, the opening position of the pressure surface on the right side of the front jet slot 4. The coordinates of point B2 are obtained. , The third preset included angle ranges from 0° to 2°.T max This represents the maximum thickness of the initial airfoil.

[0072] Step 24: See Figure 5 After determining the opening positions D1 and D2 on the right side of the jet slit 5.

[0073] Draw the normal to the initial airfoil pressure surface profile through point C1. On this normal, take a second auxiliary point at a distance of 50%Tmax from point C1. Draw a fifth auxiliary line through this second auxiliary point, forming a fourth preset angle with line C1-C2. Select the intersection of this fifth auxiliary line and the initial airfoil suction surface profile as point D1, the opening position of the suction surface on the right side of the rear jet slot 5. Obtain the coordinates of point D1. , The intersection of the fifth auxiliary line and the initial airfoil pressure surface profile is selected as point D2, the opening position of the pressure surface on the right side of the rear jet slot 5. The coordinates of point D2 are obtained. , The fourth preset included angle ranges from 0° to 2°.

[0074] Step 3: Determine the left and right boundaries of the front jet slot 4 and the rear jet slot 5.

[0075] Step 31: See Figure 6 Determine the left boundary of the front jet slot 4.

[0076] Draw the perpendicular bisector of line A1-A2 and the perpendicular line to the pressure surface profile line passing through point A2. The two perpendicular lines intersect at point O1. The coordinates of the center O1 are ( , It can be obtained from the following formula:

[0077] ;

[0078] ;

[0079] in, It is the slope of the line A1-A2. It is the slope of the tangent line passing through point A2.

[0080] With the intersection point O1 as the center, draw an arc that passes through both points A1 and A2. And as the left boundary of the front jet slot 4, the arc The profile expression is:

[0081] , .

[0082] Step 32: See Figure 7 Determine the right boundary of the front jet slot 4.

[0083] Draw the perpendicular bisector of line B1-B2 and the perpendicular line to the suction surface line passing through point B1. The two perpendicular lines intersect at point O3. The coordinates of the center O3 are ( , It can be obtained from the following formula:

[0084] ;

[0085] ;

[0086] in, It is the slope of the line B1-B2. It is the slope of the tangent line passing through point B1.

[0087] With intersection point O3 as the center, draw an arc passing through points B1 and B2. And as the right boundary of the front jet slot 4, the arc The profile expression is:

[0088] , .

[0089] Step 33: See Figure 6 The left boundary of the jet slit 5 is determined.

[0090] Draw the perpendicular bisector of line C1-C2 and the perpendicular line to the pressure surface profile passing through point C2. The two perpendicular lines intersect at point O2. The coordinates of the center O2 are ( , It can be obtained from the following formula:

[0091] ;

[0092] ;

[0093] in, It is the slope of the line C1-C2. It is the slope of the tangent line passing through point C2.

[0094] With intersection point O2 as the center, draw an arc passing through points C1 and C2. And as the left boundary of the rear jet slot 5, the arc The profile expression is:

[0095] , .

[0096] Step 34: See Figure 7 The right boundary of the jet slit 5 is determined.

[0097] Draw the perpendicular bisector of line D1-D2 and the perpendicular line to the suction surface line passing through point D1. The two perpendicular lines intersect at point O4. The coordinates of the center O4 are ( , It can be obtained from the following formula:

[0098] ;

[0099] ;

[0100] in, It is the slope of the line D1-D2. It is the slope of the tangent line passing through point D1.

[0101] With intersection point O4 as the center, draw an arc passing through points D1 and D2. And as the right boundary of the rear jet slot 5, the arc The profile expression is:

[0102] , .

[0103] In this embodiment, a gradually narrowing front jet channel is formed by the arc-shaped left and right boundaries of the front jet slot 4, and a gradually narrowing rear jet channel is formed by the arc-shaped left and right boundaries of the rear jet slot 5. The use of arc-shaped boundaries can achieve a first-order continuous and smooth transition at the junction of the jet slot and the initial blade suction surface profile, and at the junction of the pressure surface profile, avoiding unnecessary flow separation and additional losses caused by discontinuous profiles, and ensuring that the slot jet achieves the expected flow control effect.

[0104] Step 4: See Figure 8 The compressor stator blades are cut to form a double-slotted compressor with the front jet slot 4 and the rear jet slot 5.

[0105] The area enclosed by arc A1A2, line segment A1B1, arc B1B2, and line segment B2A2 is the front jet slot cut-out body, and the area enclosed by arc C1C2, line segment C1D1, arc D1D2, and line segment D2C2 is the rear jet slot cut-out body. The front jet slot cut-out body and the rear jet slot cut-out body are cut off from the initial airfoil to form the front section 1, the middle section 2, and the rear section 3 of the airfoil. Then, the leading edge radius is selected to be the same as that of the initial airfoil, and the leading edge of the middle section 2 and the rear section 3 of the airfoil is rounded. The trailing edge radius is selected to be the same as that of the initial airfoil, and the trailing edge of the front section 1 and the middle section 2 of the airfoil is rounded to form a double-slotted compressor stator airfoil with the front jet slot 4 and the rear jet slot 5.

[0106] It should be noted that in the steps of this embodiment, the leading edge of the initial blade shape is taken as the left side, and the trailing edge of the initial blade shape is taken as the right side.

[0107] Using the airfoil of the first-stage stator blade of a low Reynolds number compressor as the initial airfoil, the double-slot compressor stator blade design method is adopted for slotting. The airfoil has an incoming Mach number of 0.7 and a Reynolds number of 5E4 under design conditions. The initial airfoil is a multi-circle-arc front airfoil. The design parameters for the double slot are: the left slot position A1 of the front jet slot 4 is at 40% of the axial chord length, and the straight line A1-A2 intersects the airfoil suction surface profile at point A1. The tangents form an 18° angle. The straight line B1-B2, formed by the right-side slots B1 and B2 of the front jet slot 4, forms a 1° angle with the straight line A1-A2. The left-side slot C1 of the rear jet slot 5 is at 70% axial chord length. The straight line C1-C2 forms a 21° angle with the tangent to the airfoil suction surface profile passing through point C1. The straight line D1-D2, formed by the right-side slots D1 and D2 of the rear jet slot 5, is parallel to the straight line C1-C2. The double-slotted airfoil constructed with the above design parameters is arranged at 20%~80% of the planar blade height, resulting in a low Reynolds number double-slotted compressor stator planar blade cascade as shown... Figure 9 As shown.

[0108] The airfoil loss coefficient was determined by numerical calculation using computational fluid dynamics software. Figure 10 The paper presents a comparison of the airfoil loss coefficient changes between the initial airfoil and the double-slotted airfoil within the Reynolds number range of 3.9E4 to 4.7E5 at an incoming flow angle of attack of -1.6°. The double-slotted airfoil reduces the critical Reynolds number of the initial airfoil from 2.2E5 to 1.6E5. When the Reynolds number is below the critical Reynolds number, i.e., when the effect of the low Reynolds number is very significant, the airfoil loss of the double-slotted airfoil can be reduced by 10% to 26% compared to the initial airfoil under different low Reynolds number conditions.

[0109] Figures 11 to 14 The diagram shows a comparison of the Mach number flow fields of the initial airfoil and the double-slotted airfoil under high and low Reynolds number conditions. It can be seen that the double-slotted airfoil given in this embodiment effectively suppresses the suction surface separation zone under low Reynolds number conditions through the double-slotted jet.

[0110] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing the stator vane profile of a double-slotted compressor to suppress low Reynolds number effects, characterized in that, include: Based on the blade body (6), determine the left and right opening positions of the front jet slot (4) and the rear jet slot (5); Determine the left and right boundaries of the front jet slot (4) and the rear jet slot (5); The stator blade of the double-slotted compressor is cut to form the front jet slot (4) and the rear jet slot (5); The steps for determining the left and right opening positions of the front jet slit (4) include: On the plane containing the blade body (6), with the leading edge of the blade body (6) as the origin, and the direction from the leading edge to the trailing edge of the blade body (6) as the origin... The positive direction of the axis, perpendicular to The axis and the direction pointing towards the suction surface are Establish a two-dimensional rectangular coordinate system along the positive axis; CFD simulation of the blade body (6) under low Reynolds number conditions was performed, and the laminar separation starting point on the suction surface profile was selected as point A1, the opening position of the suction surface on the left side of the front jet slit (4). The intersection of the first auxiliary line passing through point A1 and the initial blade pressure surface profile is taken as point A2, the opening position of the pressure surface on the left side of the front jet slit (4). The first auxiliary line and the first tangent line passing through point A1 on the initial blade suction surface profile have a first preset angle. Draw the normal line of the pressure surface profile of the blade body (6) through point A1. Take the first auxiliary point at a first preset distance from point A1 on the normal line. Take the intersection of the fourth auxiliary line passing through the first auxiliary point and the suction surface profile of the blade body (6) as the opening point B1 of the suction surface of the front jet slot (4). Take the intersection of the fourth auxiliary line and the pressure surface profile of the blade body (6) as the opening point B2 of the pressure surface of the front jet slot (4). The fourth auxiliary line and the line A1-A2 form a third preset angle. The steps for determining the left and right opening positions of the jet slit (5) include: By analyzing the opening position A1 on the suction surface on the left side of the front jet slot (4), Using the axial coordinates, the Reynolds number of the stator blade of the double-slotted compressor under design conditions, and the axial chord length of the blade body (6), the position C1 of the left suction surface of the rear jet slot (5) is obtained. Axial coordinates; with the suction surface profile of the blade body (6) and point C1. The point with the same axis coordinates is point C1, the opening position of the suction surface on the left side of the rear jet slit (5); The intersection of the third auxiliary line passing through point C1 and the pressure surface profile of the blade body (6) is taken as the opening point C2 of the pressure surface on the left side of the rear jet slit (5). The third auxiliary line and the second tangent line passing through point C1 on the initial blade suction surface profile have a second preset angle. Draw the normal line of the pressure surface profile of the blade body (6) through point C1. Take the second auxiliary point at the second preset distance from point C1 on the normal line. Take the intersection of the fifth auxiliary line passing through the second auxiliary point and the initial blade suction surface profile as the opening point D1 of the suction surface of the rear jet slot (5). Take the intersection of the fifth auxiliary line and the initial blade pressure surface profile as the opening point D2 of the pressure surface of the rear jet slot (5). The fifth auxiliary line and the line C1-C2 form a fourth preset angle.

2. The method for designing the stator blade profile of a double-slotted compressor according to claim 1, characterized in that, The opening position C1 on the suction surface of the left side of the rear jet slit (5) The formula for calculating axis coordinates is: ； in, The opening position of point C1 on the suction surface on the left side of the rear jet slit (5) Axis coordinates The axial chord length of the blade body (6) The opening position A1 on the suction surface of the left side of the front jet slit (4) Axis coordinates The Reynolds number of the stator blade profile of the double-slot compressor under design conditions. is the critical Reynolds number of the leaf-shaped body (6).

3. The method for designing the stator blade profile of a double-slotted compressor according to claim 2, characterized in that, The steps for determining the left and right boundaries of the front jet slot (4) include: With the intersection point O1 of the perpendicular bisector of line A1-A2 and the normal to the pressure surface profile line passing through point A2 as the center, and the arc passing through points A1 and A2... As the left boundary of the front jet slot (4); An arc passing through points B1 and B2 is centered at point O3, the intersection of the perpendicular bisector of line B1-B2 and the normal to the suction surface profile passing through point B1. This is the right boundary of the front jet slit (4).

4. The method for designing the stator blade profile of a double-slotted compressor according to claim 3, characterized in that, The steps for determining the left and right boundaries of the back jet slot (5) include: An arc passing through points C1 and C2 is drawn with its center at point O2, where the perpendicular bisector of line C1-C2 intersects the normal to the pressure surface profile at point C2. The left boundary of the rear jet slot (5); An arc passing through points D1 and D2 is centered at point O4, the intersection of the perpendicular bisector of line D1-D2 and the normal to the suction surface profile passing through point D1. This is the right boundary of the rear jet slot (5).

5. The method for designing the stator blade profile of a double-slotted compressor according to claim 4, characterized in that, The steps of cutting and forming the stator blade profile of the double-slotted compressor having the front jet slot (4) and the rear jet slot (5) include: Define an arc Line segment A1B1, arc The area enclosed by line segment B2A2 is the body to be cut in the front jet seam, defined by an arc. Line segment C1D1, arc The area enclosed by line segment D2C2 is the rear jet slot to be cut. The front jet slot to be cut and the rear jet slot to be cut are cut off from the blade body (6) to form the front section (1), the middle section (2), and the rear section (3) of the blade. Then, the same leading edge radius as the blade body (6) is selected to round the leading edge of the middle section (2) and the rear section (3). The same trailing edge radius as the blade body (6) is selected to round the trailing edge of the front section (1) and the middle section (2) of the blade to form a double-slotted compressor stator blade with the front jet slot (4) and the rear jet slot (5).

6. A stator vane profile for suppressing low Reynolds number effects in a double-slotted compressor, designed and formed using the double-slotted compressor stator vane profile design method as described in any one of claims 1-5, characterized in that, It includes a blade body (6), a front jet slot (4), and a rear jet slot (5); the front jet slot (4) and the rear jet slot (5) are both located on the blade body (6) and extend from the pressure surface of the blade body (6) to the suction surface, dividing the blade body (6) into the front section (1), the middle section (2), and the rear section (3); the front jet slot (4) and the rear jet slot (5) are used to guide the high-pressure airflow on the pressure surface of the blade body (6) to the suction surface, so as to improve the boundary layer kinetic energy of the suction surface and weaken laminar separation.

7. The stator blade profile of the double-slotted compressor according to claim 6, characterized in that, The intersection of the left boundary of the front jet slit (4) and the suction surface profile of the blade body (6) is located at the laminar flow separation starting point on the suction surface profile.

Images