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CN-122009474-A - Method and structure for inhibiting second mode wave of high-speed boundary layer to delay transition

CN122009474ACN 122009474 ACN122009474 ACN 122009474ACN-122009474-A

Abstract

The invention discloses a method and a structure for inhibiting a second mode wave of a high-speed boundary layer to delay transition, which relate to the technical field of boundary layer flow control and comprise the steps of determining a synchronization point of a conical high-speed boundary layer according to a designed incoming flow working condition At the leading edge and the synchronization point of the tapered high-speed boundary layer An open concave cavity is arranged between the two cavities. The large-size opening concave cavity is formed in the surface of the conical high-speed boundary layer, so that the growth of the second mode wave can be effectively restrained, the transition of the high-speed boundary layer is delayed, the laminar flow design of the conical high-speed boundary layer is facilitated, and the pneumatic loss and the pneumatic heat of the high-speed boundary layer caused by the transition are reduced.

Inventors

  • Huang Ganglei
  • CHEN JIANQIANG
  • XU JUN
  • LI YANG
  • CHEN XI
  • QIN PEIJIANG
  • ZHANG ZHENHUI
  • WU DI
  • WANG XICHAO
  • TU GUOHUA

Assignees

  • 中国空气动力研究与发展中心计算空气动力研究所

Dates

Publication Date
20260512
Application Date
20260416

Claims (10)

  1. 1. A method of suppressing a second mode wave of a high velocity boundary layer to delay transition, comprising: determining the synchronous point of the conical high-speed boundary layer according to the designed incoming flow working condition ; At the leading edge (1) of the conical high-speed boundary layer and at the synchronization point An open concave cavity (2) is arranged between the two cavities.
  2. 2. Method of suppressing a second modal wave of a high velocity boundary layer to delay transitions according to claim 1, characterized in that the transition is at the leading edge (1) and synchronization point of the tapered high velocity boundary layer An open cavity (2) is arranged between the two cavities, and the device comprises: determining the boundary layer thickness at the start of the open cavity (2) ; By means of the boundary layer thickness at the starting position of the opening cavity (2) Performing unquantized processing on the cavity depth d of the opening cavity (2), wherein the cavity depth d meets 2 ≤d<4 ; And determining the flow direction length l of the open cavity (2) according to the cavity depth d of the open cavity (2), wherein the length-to-depth ratio l/d of the open cavity (2) is less than 10.
  3. 3. Method for suppressing a second modal wave of a high-speed boundary layer to delay a transition according to claim 2, characterized in that the open cavity (2) has a length to depth ratio l/d satisfying 5<l/d≤8.
  4. 4. Method for suppressing a second modal wave of a high speed boundary layer to delay transition according to claim 1, characterized in that the flow direction distance W from the start position of the open cavity (2) to the leading edge (1) of the tapered high speed boundary layer is such that /2<W<2 /3。
  5. 5. The method of suppressing a second modal wave of a high velocity boundary layer to delay transitions according to any one of claims 1-4, further comprising: Carrying out wind tunnel experiments on the concave cavity conical high-speed boundary layer and the corresponding non-concave cavity conical high-speed boundary layer to obtain a power spectrum density diagram; And respectively determining a power spectral density peak value corresponding to the second mode according to the power spectral density graphs of the concave cavity conical high-speed boundary layer and the non-concave cavity conical high-speed boundary layer.
  6. 6. The method of suppressing a second mode wave of a high speed boundary layer to delay transition according to any one of claims 1-4, wherein the synchronization point of the tapered high speed boundary layer is determined according to the designed incoming flow condition Comprising: Determining a boundary layer basic flow field according to the designed incoming flow working condition; According to the linear stability theory and Method for calculating the synchronization point of the conical high-speed boundary layer 。
  7. 7. The method of suppressing a second modal wave of a high velocity boundary layer to delay transition of any one of claims 1-4, further comprising: Numerical simulation or wind tunnel experiment is carried out on the concave cavity conical high-speed boundary layer, and the synchronous point of the concave cavity conical high-speed boundary layer is determined ; Adjusting the size and initial position parameters of the opening concave cavity (2), performing numerical simulation or wind tunnel experiment on a new concave cavity conical high-speed boundary layer, and determining corresponding synchronization points Up to No longer increases by the synchronization point As a new synchronization point 。
  8. 8. Method of suppressing a high speed boundary layer second mode wave to delay transition according to claim 7, characterized in that said adjusting of the size and starting position parameters of the open cavity (2) comprises: controlling the initial position and the length-depth ratio l/d of the opening concave cavity (2) to be unchanged, and adjusting the concave cavity depth d of the opening concave cavity (2); or controlling the cavity depth d and the length-depth ratio l/d of the opening cavity (2) to be unchanged, and adjusting the starting position of the opening cavity (2).
  9. 9. A structure for suppressing a second mode wave of a high-speed boundary layer to delay transition, manufactured by the method for suppressing a second mode wave of a high-speed boundary layer according to any one of claims 1 to 8, characterized by comprising an open cavity (2) provided at the outer periphery of an inner cone of a combustion chamber, the open cavity (2) being provided at the front edge and a synchronization point of the inner cone Between them.
  10. 10. Structure for suppressing a second modal wave of a high-speed boundary layer to delay transition according to claim 9, characterized in that the open cavity (2) is provided at the radial butt joint of the inner cone.

Description

Method and structure for inhibiting second mode wave of high-speed boundary layer to delay transition Technical Field The invention relates to the technical field of boundary layer flow control, in particular to a method for inhibiting second mode waves of a high-speed boundary layer to delay transition. In addition, the invention also provides a structure of the method for restraining the second mode wave of the high-speed boundary layer to delay transition. Background Transition of a high-speed boundary layer can lead to rapid increase of wall friction and heat flow, and is a front hot spot problem of hydrodynamic research. For different high-speed boundary layers, various instabilities may exist in the transition process, including first mode instabilities, second mode instabilities, grtler instabilities, cross-flow instabilities, attachment line instabilities, and the like. Mach number of incoming streamAt >3.7, there are a series of high-frequency unstable modes characterized by acoustic disturbance in addition to the unstable modes corresponding to T-S waves in the boundary layer. In the high-speed boundary layer study, the mode corresponding to the T-S wave is a first mode wave, and the high-frequency unstable mode is called a second mode wave, a third mode wave, or the like from low to high in frequency. Wherein the second mode wave is the least stable disturbance. Mach number of incoming streamAt a lower level, the first mode wave has a maximum growth rate, and when the incoming flow Mach numberAnd when the transition point is not less than 4, the growth rate of the second mode wave is rapidly increased, becomes the least stable disturbance, and plays a leading role in transition of the boundary layer. In summary, how to suppress the growth of the second mode wave of the high-speed boundary layer to delay the transition is a problem to be solved by those skilled in the art. Disclosure of Invention In view of the above, an object of the present invention is to provide a method for suppressing a second mode wave of a high-speed boundary layer to delay transition, in which an opening cavity with a large size is used to suppress growth of the second mode wave, so as to suppress transition of the high-speed boundary layer. In addition, the invention also provides a structure for restraining the second mode wave of the high-speed boundary layer to delay transition by applying the method for restraining the second mode wave of the high-speed boundary layer to delay transition. In order to achieve the above object, the present invention provides the following technical solutions: a method of suppressing a second mode wave of a high speed boundary layer to delay transition, comprising: determining the synchronous point of the conical high-speed boundary layer according to the designed incoming flow working condition ; At the leading edge of the tapered high velocity boundary layer and the synchronization pointAn open concave cavity is arranged between the two cavities. Preferably, the leading edge and the synchronization point of the conical high-speed boundary layerAn open cavity is arranged between the two cavities, comprising: determining the boundary layer thickness of the initial position of the opening concave cavity ; By using the boundary layer thickness at the starting position of the opening concave cavityPerforming unquantized treatment on the cavity depth d of the opening cavity, wherein the cavity depth d meets 2≤d<4; And determining the flow direction length l of the opening concave cavity according to the concave cavity depth d of the opening concave cavity, wherein the length-to-depth ratio l/d of the opening concave cavity is smaller than 10. Preferably, the length-depth ratio l/d of the opening concave cavity is 5<l/d less than or equal to 8. Preferably, the flow direction distance W from the starting position of the opening concave cavity to the front edge of the conical high-speed boundary layer is as follows/2<W<2/3。 Preferably, the method further comprises: Carrying out wind tunnel experiments on the concave cavity conical high-speed boundary layer and the corresponding non-concave cavity conical high-speed boundary layer to obtain a power spectrum density diagram; And respectively determining a power spectral density peak value corresponding to the second mode according to the power spectral density graphs of the concave cavity conical high-speed boundary layer and the non-concave cavity conical high-speed boundary layer. Preferably, the synchronous point of the conical high-speed boundary layer is determined according to the design incoming flow working conditionComprising: Determining a boundary layer basic flow field according to the designed incoming flow working condition; According to the linear stability theory and Method for calculating the synchronization point of the conical high-speed boundary layer。 Preferably, the method further comprises: Numerical simulation or wind tun