CN105740629B - A kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result - Google Patents
A kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result Download PDFInfo
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- CN105740629B CN105740629B CN201610070977.XA CN201610070977A CN105740629B CN 105740629 B CN105740629 B CN 105740629B CN 201610070977 A CN201610070977 A CN 201610070977A CN 105740629 B CN105740629 B CN 105740629B
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Abstract
The invention discloses a kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result, for current grid to be judged, search two grids of upstream and downstream in the current grid barometric gradient direction, by the comparison to the two grid intrinsic parameters, judge whether current grid should be labeled as shock wave core；If current grid is labeled as shock wave core, two hoop net case markers around current grid are denoted as shock wave edge.The method provided by the invention that shock-wave spot is determined according to Flow Field Numerical Calculation result, it is not necessary to determining for shock-wave spot can be achieved for specific flow field adjustment threshold value, therefore suitable for the analysis of full automation；Shock wave determined by the present invention is a piece of net region rather than the line without thickness, therefore is conducive to Parameters variation caused by counting shock wave.
Description
Technical field
The present invention relates to a kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result, belong to Fluid Mechanics Computation
Technology.
Background technology
Shock wave is flow phenomenon common in supersonic flows, its front and rear stream pressure, density, Mach number and flow direction
It can undergo mutation etc. parameter.It is to analyze the important letter in flow field that position, shape and the shock wave of shock wave, which cause the change of flow parameter,
Breath.At present in the Flow Field Numerical Calculation method of mainstream, shock wave is captured naturally in calculating process, to the definite need of shock-wave spot
Will be according to result of calculation post-processing.And nearby parameter often has fluctuation to shock wave in numerical computations, directly according to gradient magnitude
Identify that shock wave is relatively difficult.
Document " Shock detection from computational fluid dynamics results "
(Lovely D, Hairnes R) proposes to be used as shock surface as 1 contour surface in the upward component of pressure gradient method using Mach number
Method.Document " Review of shock wave detection method in CFD post-processing " (Wu Z
N, Xu Y Z, Wang W B, et al.) consider mesh scale, and introduce flow direction velocity variations and the above method is carried out
Further improvement.But these methods are both needed to artificial given threshold value and are filtered, and the setting of threshold value is often flowed with specific
Field is related, can not adapt to the needs of automatic identification.
The content of the invention
Goal of the invention：In order to overcome the deficiencies in the prior art, the present invention provides one kind according to Flow Field Numerical Calculation
As a result the method for determining shock-wave spot, can automatically determine shock-wave spot and can according to Flow Field Numerical Calculation result
Flow parameter variable quantity caused by analyzing shock wave.
Technical solution：To achieve the above object, the technical solution adopted by the present invention is：
A kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result, for current grid to be judged, is searched
Two grids of upstream and downstream in the current grid barometric gradient direction, by the comparison to the two grid intrinsic parameters, judge
Whether current grid should be labeled as shock wave core；If current grid is labeled as shock wave core, by two around current grid
Hoop net case marker is denoted as shock wave edge.
This method specifically comprises the following steps：
(1) for current grid c0, current grid c is found out from 8 adjacent around grids0Barometric gradient direction
Two grids of upstream and downstream, upstream grid are denoted as cup, downstream grid is denoted as cdown；By current grid c0Remember in barometric gradient direction
ForUpstream grid is directed toward c for grid element center in 8 grids0Center vector withAngle minimum grid, downstream net
Lattice are directed toward c for grid element center in 8 grids0Center vector withAngle maximum grid；The velocity vector of upstream grid
It is denoted asThe velocity vector of downstream grid is denoted as
(2) judge whether the parameter in upstream grid and downstream grid meets with lower inequality：
In formula：aupAnd adownRepresent the velocity of sound of upstream grid and downstream grid, ρupAnd ρdownRepresent upstream grid and downstream
The density of grid
If meeting above-mentioned inequality, current grid c is judged0For shock wave core, and by preceding grid c0Two hoop net lattice of surrounding
Labeled as shock wave edge.
Beneficial effect：The method provided by the invention that shock-wave spot is determined according to Flow Field Numerical Calculation result, it is not necessary to pin
Shock-wave spot can be achieved to specific flow field adjustment threshold value to determine, therefore suitable for the analysis of full automation；Institute of the present invention
Definite shock wave is a piece of net region rather than the line without thickness, therefore is conducive to Parameters variation caused by counting shock wave.
Brief description of the drawings
Fig. 1 is to judge whether current grid should be labeled as the schematic diagram of shock wave core；
Fig. 2 is to be marked as the grid of shock wave core and be marked as the schematic diagram of the grid at shock wave edge；
Fig. 3 is the schematic diagram of the theoretical position of the shock wave region of this algorithm tag and shock wave contrast in embodiment；
Fig. 4 is the enlarged drawing of regional area in Fig. 3.
In figure：1- current grids c0, 2- current grids c0Barometric gradient direction3- downstreams grid cdown, 4- downstreams
Grid cdownVelocity vector5- upstreams grid cup, 6- upstreams grid cupVelocity vector7- is labeled as shock wave
Grid, the three stage compression inclined wedge of 8- embodiments mark the region for being in 9- embodiments, the theory of shock wave in 10- embodiments
Position, the part shock wave region in 11- embodiments.
Embodiment
The present invention is further described below in conjunction with the accompanying drawings.
A kind of method that shock-wave spot is determined according to Flow Field Numerical Calculation result, as shown in Figure 1, for be judged current
Grid, searches two grids of upstream and downstream in the current grid barometric gradient direction, by the two grid intrinsic parameters
Compare, judge whether current grid should be labeled as shock wave core；If current grid is labeled as shock wave core, by current grid
Two hoop net case markers of surrounding are denoted as shock wave edge (as shown in Figure 2).This method specifically comprises the following steps：
(1) for current grid c0, current grid c is found out from 8 adjacent around grids0Barometric gradient direction
Two grids of upstream and downstream, upstream grid are denoted as cup, downstream grid is denoted as cdown；By current grid c0Remember in barometric gradient direction
ForUpstream grid is directed toward c for grid element center in 8 grids0Center vector withAngle minimum grid, downstream net
Lattice are directed toward c for grid element center in 8 grids0Center vector withAngle maximum grid；The velocity vector of upstream grid
It is denoted asThe velocity vector of downstream grid is denoted as
(2) judge whether the parameter in upstream grid and downstream grid meets with lower inequality：
In formula：aupAnd adownRepresent the velocity of sound of upstream grid and downstream grid, ρupAnd ρdownRepresent upstream grid and downstream
The density of grid
If meeting above-mentioned inequality, current grid c is judged0For shock wave core, and by preceding grid c0Two hoop net lattice of surrounding
Labeled as shock wave edge.
The present invention is further illustrated with reference to one embodiment.
The free stream Mach number of the present embodiment is 6, pressure 2511Pa, temperature 211.6K, oblique in three-level using this algorithm
The nothing of wedge pressure contracting, which is glued, extracts shock wave region in numerical result, three-level inclined wedge compression angle be respectively 5.07 °, 5.71 ° and
6.47 °, compressing surface length 476mm, grid amount is about 100,000.Fig. 3 and Fig. 4 shows the shock-wave spot and theory of this algorithm extraction
The contrast of upper shock-wave spot, table 1 show this algorithm to the pressure ratio and the result of calculation of total pressure recovery coefficient in shock wave region, with
And the pressure ratio and total pressure recovery coefficient of shock wave in theory.
Flow parameter caused by 1 shock wave of table changes
It is good from visible algorithm extraction result of comparing result and theoretical calculation.
The above is only the preferred embodiment of the present invention, it should be pointed out that：For the ordinary skill people of the art
For member, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications also should
It is considered as protection scope of the present invention.
Claims (1)
- A kind of 1. method that shock-wave spot is determined according to Flow Field Numerical Calculation result, it is characterised in that：For to be judged current Grid, searches two grids of upstream and downstream in the current grid barometric gradient direction, by the two grid intrinsic parameters Compare, judge whether current grid should be labeled as shock wave core；If current grid is labeled as shock wave core, by current grid Two hoop net case markers of surrounding are denoted as shock wave edge；This method specifically comprises the following steps：(1) for current grid c0, current grid c is found out from 8 adjacent around grids0The upstream in barometric gradient direction With two, downstream grid, upstream grid is denoted as cup, downstream grid is denoted as cdown；By current grid c0Barometric gradient vector is denoted asUpstream grid is directed toward c for grid element center in 8 grids0Center vector withAngle minimum grid, downstream grid C is directed toward for grid element center in 8 grids0Center vector withAngle maximum grid；The velocity vector note of upstream grid ForThe velocity vector of downstream grid is denoted as(2) judge whether the parameter in upstream grid and downstream grid meets with lower inequality：<mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <msub> <mover> <mi>V</mi> <mo>&RightArrow;</mo> </mover> <mrow> <mi>u</mi> <mi>p</mi> </mrow> </msub> <mo>&CenterDot;</mo> <mover> <mo>&dtri;</mo> <mo>&RightArrow;</mo> </mover> <mi>p</mi> <mo>&GreaterEqual;</mo> <msub> <mi>a</mi> <mrow> <mi>u</mi> <mi>p</mi> </mrow> </msub> <mo>|</mo> <mover> <mo>&dtri;</mo> <mo>&RightArrow;</mo> </mover> <mi>p</mi> <mo>|</mo> </mtd> </mtr> <mtr> <mtd> <msub> <mover> <mi>V</mi> <mo>&RightArrow;</mo> </mover> <mrow> <mi>d</mi> <mi>o</mi> <mi>w</mi> <mi>n</mi> </mrow> </msub> <mo>&CenterDot;</mo> <mover> <mo>&dtri;</mo> <mo>&RightArrow;</mo> </mover> <mi>p</mi> <mo>&GreaterEqual;</mo> <msub> <mi>a</mi> <mrow> <mi>d</mi> <mi>o</mi> <mi>w</mi> <mi>n</mi> </mrow> </msub> <mo>|</mo> <mover> <mo>&dtri;</mo> <mo>&RightArrow;</mo> </mover> <mi>p</mi> <mo>|</mo> </mtd> </mtr> <mtr> <mtd> <msub> <mi>&rho;</mi> <mrow> <mi>u</mi> <mi>p</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>&rho;</mi> <mrow> <mi>d</mi> <mi>o</mi> <mi>w</mi> <mi>n</mi> </mrow> </msub> </mtd> </mtr> </mtable> </mfenced>In formula：aupAnd adownRepresent the velocity of sound of upstream grid and downstream grid, ρupAnd ρdownRepresent upstream grid and downstream grid DensityIf meeting above-mentioned inequality, current grid c is judged0For shock wave core, and by preceding grid c0Two hoop net case markings of surrounding For shock wave edge.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103413060A (en) * | 2013-08-26 | 2013-11-27 | 中国人民解放军国防科学技术大学 | Cell-centered grid data three-dimensional shock wave feature positioning method based on dual control volumes |
| CN105038787A (en) * | 2015-07-01 | 2015-11-11 | 上海应用技术学院 | Ce, Tb and Mn-coactivated single-matrix phosphate white phosphor powder and preparation method thereof |
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2016
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103413060A (en) * | 2013-08-26 | 2013-11-27 | 中国人民解放军国防科学技术大学 | Cell-centered grid data three-dimensional shock wave feature positioning method based on dual control volumes |
| CN105038787A (en) * | 2015-07-01 | 2015-11-11 | 上海应用技术学院 | Ce, Tb and Mn-coactivated single-matrix phosphate white phosphor powder and preparation method thereof |
Non-Patent Citations (6)
| Title |
|---|
| Review of shock wave detection method in CFD post-processing;Wu Ziniu 等;《Chinese Journal of Aeronautics》;20130514;第26卷(第3期);第501-513页 * |
| Shock Detection from Computational Fluid Dynamics Results;David Lovely等;《American Institute of Aeronautics And Astronautics Paper》;19990731;第1-9页 * |
| 一种二维自适应网格构造方法及其实现;徐涛 等;《计算物理》;19990131;第16卷(第1期);第66-76页 * |
| 基于两级采样的非结构化网格流场多激波特征可视化方法;马千里 等;《计算机研究与发展》;20120731;第49卷(第7期);第1450-1459页 * |
| 基于商用CFD软件的乘波体气动外形设计方法研究;李名扬 等;《力学季刊》;20140630;第35卷(第2期);第293-299页 * |
| 高超声速气动力及激波位置快速计算方法研究;段焰辉 等;《航空工程进展》;20130228;第4卷(第1期);第28-36,70页 * |
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