CN112001099A - Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope - Google Patents

Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope Download PDF

Info

Publication number
CN112001099A
CN112001099A CN202010644727.9A CN202010644727A CN112001099A CN 112001099 A CN112001099 A CN 112001099A CN 202010644727 A CN202010644727 A CN 202010644727A CN 112001099 A CN112001099 A CN 112001099A
Authority
CN
China
Prior art keywords
antenna
wind
wind pressure
calculating
node
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.)
Pending
Application number
CN202010644727.9A
Other languages
Chinese (zh)
Inventor
许谦
王从思
苗思源
王娜
何飞龙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xinjiang Astronomical Observatory of CAS
Original Assignee
Xinjiang Astronomical Observatory of CAS
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xinjiang Astronomical Observatory of CAS filed Critical Xinjiang Astronomical Observatory of CAS
Priority to CN202010644727.9A priority Critical patent/CN112001099A/en
Publication of CN112001099A publication Critical patent/CN112001099A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2113/00—Details relating to the application field
    • G06F2113/08—Fluids
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Evolutionary Computation (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • Algebra (AREA)
  • Computing Systems (AREA)
  • Fluid Mechanics (AREA)
  • Mathematical Analysis (AREA)
  • Mathematical Optimization (AREA)
  • Mathematical Physics (AREA)
  • Pure & Applied Mathematics (AREA)
  • Aerials With Secondary Devices (AREA)

Abstract

The invention relates to a method for quickly measuring and calculating the pulsating wind pressure of an antenna panel of a large radio telescope, which comprises the following steps: determining the geographic position of the radio telescope and constructing a radio telescope antenna model; measuring antenna geographic parameters, and determining antenna reflector node information and antenna reflector unit information; calculating the heights of different nodes on the antenna reflecting surface; calculating a pulsating wind speed sample of any node on the antenna reflecting surface; measuring a wind direction angle according to the antenna attitude and the wind direction in the actual environment; according to the pulsating wind speed sample, calculating the wind pressure of any node of the antenna panel under different wind direction angles to obtain a wind pressure file which can be directly applied to an antenna model constructed in finite element analysis software, and calculating the influence of wind load on the antenna. Based on the method of the invention, a user can realize the rapid generation of the random wind pressure of the surface antenna without deeply knowing the complex theory of the wind speed generation, thereby providing convenience for analyzing the wind load influence of the antenna by adopting finite element software such as ANSYS and the like.

Description

Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope
Technical Field
The invention relates to the technical field of antennas, in particular to a method for quickly measuring and calculating pulsating wind pressure of an antenna panel of a large radio telescope.
Background
For a large radio telescope antenna structure, wind load is an important load of the structural design and sometimes even plays a decisive role. The time course curve of downwind wind contains two components: one is a long cycle part, which is often more than 10 minutes; the other is a short period part, often only a few seconds or so. Accordingly, wind is often divided into average wind (also called steady wind) and pulsating wind (also called transient wind) for analysis. The long period of the average wind is far longer than the natural vibration period of the common structure, and the speed and the direction of the acting force on the structure are static without changing with time. The pulsating wind is caused by the irregularity of wind, the intensity of which changes in random rule with time, the period of which is short, the action property of which is dynamic, and the vibration of the structure is caused to be treated by the random vibration theory. The wind calculation is mainly for pulsating wind. The wind speed V (x, y, z) acting on any point coordinate (x, y, z) on the structure is the average wind speed
Figure BDA0002572597150000011
And sum of the pulsating wind speed v (x, y, z, t):
Figure BDA0002572597150000012
at present, most of the wind vibration analysis of the engineering structure is carried out on a frequency domain, and the time domain analysis of the wind load response of the structure is still necessary. The wind load measurement and calculation method needs to be developed for wind load analysis of an antenna structure in a time domain range, and the method relates to special and deep knowledge and measurement and calculation methods such as a gradient wind formula, wind speed spectrum density function calculation, transformation from a frequency domain to a time domain and the like, and is difficult to calculate by a common technician. Therefore, it is necessary to provide a method for measuring and calculating the pulsating wind pressure of an antenna panel, so as to obtain a wind pressure file which can be directly applied to an antenna ANSYS finite element model, thereby providing wind load information in a time domain for wind load analysis of an antenna structure.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides the method for quickly measuring and calculating the pulsating wind pressure of the antenna panel of the large radio telescope, and a user can quickly generate the pulsating wind pressure of the surface antenna without deeply knowing a complex theory of wind speed generation, so that convenience is provided for analyzing the influence of the wind load of the antenna by using finite element software such as ANSYS and the like.
The invention provides a method for quickly measuring and calculating the pulsating wind pressure of an antenna panel of a large radio telescope, which comprises the following steps:
step S1, determining the geographic position of the radio telescope, and constructing a radio telescope antenna model in finite element analysis software;
step S2, according to the geographic position of the radio telescope, measuring the geographic parameters of the antenna, and according to the radio telescope antenna model, determining the node information of the antenna reflecting surface;
step S3, calculating the heights of different nodes on the antenna reflecting surface according to the antenna geographic parameters and the antenna reflecting surface node information;
step S4, calculating a pulsating wind speed sample of any node on the antenna reflecting surface according to the antenna geographic parameters and the heights of different nodes on the antenna reflecting surface;
step S5, measuring a wind direction angle according to the antenna posture and the wind direction in the actual environment;
and step S6, calculating the wind pressure applied to any point of the antenna panel under different wind direction angles according to the pulsating wind speed sample calculated in the step S4, and obtaining a wind pressure file which can be directly applied to an ANSYS finite element model of the antenna.
The antenna geographic parameters in the step S2 include a standard height of the antenna location, a turbulence scale, a wind speed at the standard height, and a ground roughness.
The antenna reflection surface node information in step S2 includes the ordinate of the reflection surface vertex, the total number of reflection surface nodes, and the coordinates of each reflection surface node.
In step S3, the heights S of different nodes on the antenna reflection surface are:
S＝smin+(k-1)×Δs
wherein s isminAnd K is the lowest height of the antenna panel, the number of the heights of the antenna reflecting surface nodes is K, the K is 1,2.
The step S4 includes:
and step S41, performing the pulse wind calculation by using the modified Davenport spectrum:
Figure BDA0002572597150000031
in the formula (I), the compound is shown in the specification,
Figure BDA0002572597150000032
is the overall size of the turbulence, which Davenport takes as 1200 m;
Figure BDA0002572597150000033
is the average wind speed at height z from the ground; f is the pulsating wind frequency; sigma is the standard deviation of the fluctuating wind speed; svRepresenting a density self-spectrum function of the pulsating wind speed process; and alpha is the roughness of the ground.
From the recording of the wind, the pulsating wind can be considered as a gaussian process and a stationary random process. Observing m stationary random processes v with zero meanj(t) (j ═ 1,2, …, m) with a spectral density function matrix of:
Figure BDA0002572597150000034
in the formula (I), the compound is shown in the specification,ωis the angular frequency; element Sjk(ω) (j, k ═ 1,2, …, m) is the fourier transform of the correlation function, whose cross spectrum is generally complex, so the matrix is complex. Due to the fact that
Figure BDA0002572597150000037
Are conjugated, so the matrix has Hermite properties. Thus, the matrix is known to be non-negative.
According to the Cholesky decomposition method,S(ω) can be decomposed into:
S(ω)＝H(ω)H*(ω)T
wherein, H (omega) is a lower triangular matrix:
Figure BDA0002572597150000035
step S42, calculating a pulsating wind speed:
Figure BDA0002572597150000036
where j is 1,2, …, N, N ≦ N, which indicates that the wind spectrum is divided into N equal parts in the frequency range, Δ ω is the frequency increment (step size), | Hjm(ωl) I is the modulus, psi, of the lower triangular matrix elementjm(ωl) Is the phase angle between two points at which the pulsating wind acts. ThetamlAre uniformly distributed random numbers between 0 and 2 pi.
Step S43, substituting different height values of the antenna reflection surface nodes into the corrected Davenport spectrum,
and calculating the wind speed samples of any node at different heights.
The step S6 includes:
step S61, calculating the wind pressure coefficient of any node of the antenna reflecting surface by using a wind tunnel test and a planar linear interpolation method;
step S62, calculating the area of the wind pressure at any node on the antenna panel;
and step S63, calculating the wind pressure received by any node of the antenna panel according to the pulsating wind speed sample calculated in the step S4, the wind pressure coefficient obtained in the step S61 and the wind pressure receiving area of any node obtained in the step S62.
And step S64, according to the information of the antenna reflecting surface units, combining the wind pressure received by any node of the antenna panel calculated in the step S63 with a finite element operation command in finite element analysis software to obtain a wind pressure file directly applied to the antenna model.
The step S61 includes:
step S611, measuring a wind pressure coefficient of a specific node of the antenna reflecting surface by using a wind tunnel experiment;
and step S612, if the node coordinates do not coincide with the coordinates of the measuring points of the wind tunnel experiment, performing interpolation according to the wind pressure coefficients of the measuring points of the wind tunnel experiment to obtain the wind pressure coefficient of the antenna net panel.
Wind pressure coefficient C of antenna net panelΔPmeshComprises the following steps:
Figure BDA0002572597150000041
wherein, CΔPsolidIs the wind pressure coefficient of the antenna real panel; cDmeshAnd CDsolidThe wind pressure coefficients of the common net surface flat plate and the common solid surface flat plate are obtained through a wind tunnel test.
The area of the wind pressure at any node in the step S62 is composed of four panel portions around the node.
Wind pressure P suffered by any node of antenna paneld(t) is:
Figure BDA0002572597150000042
where v (t) is the random pulsating wind speed at any node on the antenna reflection surface calculated in step S4, ρ is the air density, and CdPIs the wind pressure coefficient on the reflecting surface of the node, Ad1The area of the node corresponding to the wind pressure is obtained.
The method is based on the internationally recognized Davenport wind speed spectrum and the random process theory, and utilizes the known antenna model parameters and the structural characteristics thereof to calculate the antenna wind pressure information of the pulsating wind load under different wind direction angles, thereby providing the wind load information in the time domain for further wind load analysis of the structure. Based on the method, the wind pressure file which can be directly applied to the antenna ANSYS finite element model is obtained. A user can realize the rapid calculation of the random wind pressure of the surface antenna without deeply knowing a complex theory of wind speed calculation, thereby providing convenience for analyzing the wind load influence of the antenna by adopting finite element software such as ANSYS and the like. In addition, the invention utilizes the distribution of the wind pressure coefficient of the reflecting surface measured by a wind tunnel experiment, and an interpolation method is used in the interior of the antenna reflecting surface, so that the wind pressure coefficient of each point on the reflecting surface can be conveniently calculated.
Drawings
FIG. 1 is a flow chart of a method for rapidly measuring and calculating pulsating wind pressure of an antenna panel of a large radio telescope according to the invention.
FIG. 2 is a Davenport pulsating wind speed spectrum.
FIG. 3 is a wind speed sample plot of 20m/s average wind speed at 10m height.
Fig. 4(a) is a schematic view of the antenna receiving side wind pressure during the day-up, fig. 4(b) is a schematic view of the antenna receiving normal wind pressure during the day-down, and fig. 4(c) is a schematic view of the antenna receiving wind pressure in other postures.
Fig. 5 is a wind pressure coefficient distribution diagram when the antenna is pointed.
Fig. 6 is a wind pressure coefficient distribution diagram of the antenna in the sky.
FIG. 7 is a distribution of panel wind load.
FIG. 8(a) is the wind load vector of the node force of the antenna structure, FIG. 8(b) is the wind pressure area of the panel corresponding to the node, FIG. 8(c) is the projection of the wind pressure area of the panel corresponding to the node on the mouth surface,
FIG. 9 is a projection of the wind pressure area of the panel corresponding to the node point and the area of the opening.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
When the antenna wind load analysis is carried out, due to the complexity of the antenna structure and the uncertainty of the random wind load, the following simplification needs to be made: firstly, only the wind load borne by the front face of the antenna is considered; secondly, wind load power is equivalent to concentrated power and acts on a main force skeleton node connected with the antenna panel; at any moment, the pulsating wind at each node on the antenna panel is completely related (namely, the pulsating wind speed and the node position have interdependence relation with unfixed relation value, after the node position is determined, the value of the pulsating wind speed is related to the node position but can not be completely determined, and is a non-deterministic relation), and the average wind speeds at different heights are equal; and fourthly, only considering the random pulsation in the downwind direction, wherein the differential pressure coefficient acting on the panel is a quasi-static value obtained by a wind tunnel experiment.
Based on the simplification, the method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large radio telescope, as shown in fig. 1, comprises the following steps:
and step S1, determining the geographic position of the large radio telescope, and constructing a radio telescope antenna model in ANSYS finite element analysis software.
And step S2, measuring the antenna geographic parameters according to the geographic position of the radio telescope, and determining the caliber of the circular paraboloid antenna, the node information of the antenna reflecting surface and the unit information of the antenna reflecting surface according to the constructed antenna model.
The antenna reflecting surface node information comprises a reflecting surface vertex ordinate, reflecting surface node total and reflecting surface node coordinates, and the antenna reflecting surface unit information comprises reflecting surface unit types and reflecting surface unit total. The information can be used for calculating the height of a specific node on the antenna reflecting surface, and finally calculated pulsating wind speed is applied to the antenna panel node, so that wind pressure information suffered by the antenna can be obtained.
The antenna geographic parameters comprise the height of an antenna panel, the geographic height of the position where the antenna is located, a turbulence scale, the wind speed at the height of the antenna panel and the ground roughness, and are used for calculating the subsequent random fluctuating wind speed. The larger the ground roughness is, the larger the air friction force is, the more the wind speed is reduced, the more the fluctuation of the pulsating wind speed is obvious, and the coefficient is determined by local experiments for installing the antenna and can be selected according to the load specification of China. The roughness of the ground is classified into A, B, C types: the A category refers to offshore sea surface, island, desert and the like, and alpha is 0.12; the B category refers to fields, villages, jungles, hills, medium and small towns with sparser houses, suburbs of big cities and open flat areas, and alpha is 0.16; the C category refers to the urban area with the average building height of more than 15m or dense building groups, and alpha is 0.20.
And step S3, calculating the heights of different nodes on the antenna reflecting surface according to the antenna geographic parameters and the antenna reflecting surface node information.
Specifically, the lowest height s of the antenna panel is determined according to the geographical height of the antenna panel and the node information of the antenna reflecting surfaceminThe height difference Δ z between the antenna reflection surface nodes and the height number a of the antenna reflection surface nodes, a being 1,2.. a, a being the total number of the reflection surface nodes, the height z of different nodes on the antenna reflection surface is:
z＝zmin+(a-1)×Δz (1)
and step S4, calculating random fluctuating wind speed samples of any node on the antenna reflection surface according to the antenna geographic parameters measured in the step S2 and the heights of different nodes of the antenna reflection surface calculated in the step S3. The method specifically comprises the following steps:
step S41, the Davenport spectrum is widely adopted due to its simple form and strong representativeness. However, many observations indicate that the Davenport spectrum overestimates the turbulence energy at high frequencies (f > 0.05Hz), and these frequency ranges are significant for high-rise structures, since the natural frequencies of the high-rise structures mostly fall within this range. For high-rise structures, wind velocity spectra that vary along the height should be used, such as Kaimal spectra, Simiu spectra, etc. Therefore, according to the parameters obtained by actual measurement, the modified Davenport spectrum is used for calculating the pulsating wind:
Figure BDA0002572597150000071
in the formula (I), the compound is shown in the specification,
Figure BDA0002572597150000072
is the overall size of the turbulence, which Davenport takes as 1200 m;
Figure BDA0002572597150000073
is the average wind speed at height z from the ground; where f is the pulsating wind frequency (as in FIG. 2); sigma is the standard deviation of the fluctuating wind speed; svRepresenting a density self-spectrum function of the pulsating wind speed process; and alpha is the roughness of the ground. Calculating to obtain a spectral density function matrix S by using the formula (2)v。
From the recording of the wind, the pulsating wind can be considered as a gaussian process and a stationary random process. Observing n stationary random processes v with zero meanj(t) (j ═ 1,2, …, m) with a spectral density function matrix of:
Figure BDA0002572597150000074
in the formula, omega is angular frequency; element Sjk(ω) (j, k ═ 1,2, …, m) is the fourier transform of the correlation function, whose cross spectrum is generally complex, so the matrix is complex. Due to the fact that
Figure BDA0002572597150000075
Are conjugated, so the matrix has Hermite properties. Thus, the matrix is known to be non-negative.
According to the Cholesky decomposition method,S(ω) can be decomposed into:
S(ω)＝H(ω)H*(ω)T (4)
wherein, H (omega) is a lower triangular matrix:
Figure BDA0002572597150000081
step S42, calculating a pulsating wind speed as:
Figure BDA0002572597150000082
wherein j is 1, and j is a linear or branched structure,2, …, N, N is less than or equal to N, which means that the wind spectrum is divided into N same parts in the frequency range, wherein the wind spectrum reflects the frequency structure of natural wind pulsation through long-term observation of natural wind and a wind spectrum model established based on a large amount of measured data. Δ ω is the frequency increment (step length), | Hjm(ωl) I is the modulus, psi, of the lower triangular matrix elementjm(ωl) Is the phase angle between two points at which the pulsating wind acts. ThetamlAre uniformly distributed random numbers between 0 and 2 pi. It can be seen that as long as the calculated frequency step Δ ω and time step t are sufficiently small, the power spectrum obtained from the pulsating wind speed time-course curve can approach the original power spectrum more closely, so that the actual condition of the pulsating wind can be simulated more accurately, and the calculation result is as shown in fig. 3.
And step S43, substituting the corrected Davenport spectrum into the values of different heights of the antenna reflecting surface nodes according to the formula (2) to the formula (6), and calculating the wind speed samples of any nodes at different heights.
Step S5, determining the orientation of the wind direction to the antenna, i.e. the wind direction angle, according to the antenna attitude and the wind direction in the actual environment, so as to determine whether the wind pressure received by the antenna is the side-blowing wind pressure received when the antenna is facing upward, the normal-blowing wind pressure received when the antenna is pointed at normal times, or the wind pressure received when the side-blowing wind direction angle is 30 degrees, 60 degrees or other angles. Wind loads on the antenna in different postures are shown in fig. 4(a) -4 (b).
And step S6, calculating the wind pressure received by any point of the antenna panel under different wind direction angles according to the wind speed samples calculated in the step S4. The method specifically comprises the following steps:
and step S61, calculating the wind pressure coefficient of any point of the antenna reflecting surface by using a wind tunnel test and a planar linear interpolation method. The method comprises the following steps:
step S611, measure the wind pressure coefficient of the antenna specific node. The wind pressure coefficient has a large relationship with the curvature (the focal ratio is the ratio of the reflection surface to the focal length) of the antenna panel, and the pitch angles are different, and the values are also different. Wind tunnel experiments can be used for measuring the wind pressure coefficient of certain specific nodes of the antenna, as shown in fig. 5 and 6, the pitching 0 degree in the graph means that the wind load acting direction is parallel to the focal axis of the antenna and is coplanar.
In step S612, the wind pressure coefficients of other nodes on the antenna panel can be obtained by an interpolation method, that is, if the node coordinates do not coincide with the coordinates of the measurement points of the wind tunnel experiment, the wind pressure coefficients of the measurement points of the wind tunnel experiment are interpolated. In fig. 5 and 6, the wind pressure coefficient of the solid panel is shown, and the wind pressure coefficient of the mesh panel can be corrected by the following formula:
Figure BDA0002572597150000091
wherein, CΔPmeshIs the wind pressure coefficient of the antenna net panel, CΔPsolidIs the wind pressure coefficient of the antenna real panel; cDmeshAnd CDsolidThe wind pressure coefficients of the common net surface flat plate and the common solid surface flat plate are obtained through wind tunnel tests.
And step S62, calculating the area of the wind pressure at any node on the antenna panel. When the antenna is subjected to wind load, wind acts on an antenna panel, the wind is transmitted to main force framework nodes by the panel, the wind load of the nodes is usually calculated according to the wind-bearing area shared by the main force framework nodes of the antenna, and the wind-bearing pressure area of the nodes is composed of parts of four panels around the nodes. Referring to fig. 7, the wind pressure area of node F is determined as follows: and the middle points of the node E and the node F are taken as an arc bb, the middle points of the node F and the node G are taken as an arc cc, the fan-shaped area bbcc is the wind-receiving area shared by the node F, and the fan-shaped area aabb is the wind-receiving pressure area shared by the node E.
And step S63, calculating the wind pressure applied to any point of the antenna panel according to the wind speed sample calculated in the step S4, the wind pressure coefficient obtained in the step S61 and the node wind area obtained in the step S62.
Basic wind pressure w acting on antenna panel0(N/m2) The relationship to wind speed is:
Figure BDA0002572597150000092
where v is the wind speed (m/s) and γ is the weight of air per unit volume.Under the conditions of air pressure of 0.01MPa, normal temperature of 15 ℃ and absolute drying, gamma is 12.018N/m3G is generally 9.8m/s2At this time w0＝v2/1.63。
The wind pressure is usually calculated according to the following formula:
Figure BDA0002572597150000093
in the formula, CpThe wind pressure coefficient (wind load type coefficient) was determined by experiment.
If the average wind (static force) is considered separately, the static force relation of the D-th main force skeleton node (D are set) connected with the antenna panel is as follows:
Figure BDA0002572597150000101
in the formula, CdPRho is the air pressure coefficient on the reflecting surface where the node is positioned, and is the air density,
Figure BDA0002572597150000103
is the average wind speed at a selected height z, Ad1The node wind pressure area calculated in step S52 is a minute area perpendicular to the normal line of the node, as shown in fig. 8(a) -8 (c). For calculation, as shown in FIG. 9, the area A is first determinedd1Projected onto the aperture plane of the antennad2Then, according to the cosine relation of the node, obtain Ad1：
Ad1＝Ad2/cos2β (9)
Wherein beta is an included angle between a node tangent line and the vertical direction.
The node wind-load dynamic formula containing random pulsation is as follows:
Figure BDA0002572597150000102
wherein V (t) is an arbitrary section on the antenna reflection surface calculated in step S3Random pulsating wind speed of a point, ρ is air density, CdPIs the wind pressure coefficient on the reflecting surface of the node, Ad1The wind pressure area, P, of the panel corresponding to the nodedAnd (t) is the wind pressure on any point on the antenna panel.
And step S64, according to the element type and the element number of the antenna panel finite element model, combining the wind pressure received by each node of the antenna panel with an ANSYS finite element operation command to obtain a wind pressure file which can be directly applied to the antenna ANSYS finite element model.
The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.

Claims (10)

1. A method for quickly measuring and calculating the pulsating wind pressure of an antenna panel of a large radio telescope is characterized by comprising the following steps:
step S1, determining the geographic position of the radio telescope, and constructing a radio telescope antenna finite element model in finite element analysis software;
step S2, according to the geographic position of the radio telescope, measuring the geographic parameters of the antenna, and according to the finite element model of the radio telescope antenna, determining the node information of the antenna reflecting surface and the unit information of the antenna reflecting surface;
step S3, calculating the heights of different nodes on the antenna reflecting surface according to the antenna geographic parameters and the antenna reflecting surface node information;
step S4, calculating a pulsating wind speed sample of any node on the antenna reflecting surface according to the antenna geographic parameters and the heights of different nodes on the antenna reflecting surface;
step S5, measuring a wind direction angle according to the antenna posture and the wind direction in the actual environment;
and step S6, calculating the wind pressure applied to any point of the antenna panel under different wind direction angles according to the pulsating wind speed sample calculated in the step S4, and obtaining a wind pressure file applied to the finite element model of the antenna.
2. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 1, wherein the geographic parameters of the antenna in the step S2 comprise a standard height of the antenna, a turbulence scale, a wind speed at the standard height and a ground roughness.
3. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 1, wherein the node information of the reflecting surface of the antenna in the step S2 includes a vertical coordinate of the vertex of the reflecting surface, the total number of the nodes of the reflecting surface, and the coordinates of the nodes of the reflecting surface.
4. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 1, wherein the heights z of different nodes on the antenna reflection surface in the step S3 are as follows:
z＝zmin+(a-1)×Δz，
zmin is the lowest height of the antenna panel, a is the height number of the antenna reflecting surface nodes, a is 1,2.
5. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 1, wherein the step S4 comprises the steps of:
step S41, the modified Davenport spectrum is used for carrying out the simulation of the pulsating wind:
Figure FDA0002572597140000021
in the formula (I), the compound is shown in the specification,
Figure FDA0002572597140000022
is the overall size of the turbulence, which Davenport takes as 1200 m;
Figure FDA0002572597140000023
is the average wind speed at height z from the ground; f is the pulsating wind frequency; sigma is the standard deviation of the fluctuating wind speed; svRepresenting a density self-spectrum function of the pulsating wind speed process; alpha is the roughness of the ground;
observing m stationary random processes v with zero meanj(t) (j ═ 1,2, …, m), the pulse wind spectral density function matrixS(ω) is:
Figure FDA0002572597140000024
in the formula, omega is angular frequency; element Sjk(ω) (j, k ═ 1,2, …, m) is the fourier transform of the correlation function;
will be provided withS(ω) is decomposed into:
S(ω)＝H(ω)H*(ω)T，
wherein, H (omega) is a lower triangular matrix:
Figure FDA0002572597140000025
step S42, calculating a pulsating wind speed:
Figure FDA0002572597140000026
where j is 1,2, …, N, N ≦ N, which indicates that the wind spectrum is divided into N equal parts in the frequency range, Δ ω is the frequency increment (step size), | Hjm(ωl) I is the modulus, psi, of the lower triangular matrix elementjm(ωl) Is the phase angle between two points at which the pulsating wind acts. ThetamlIs a random number uniformly distributed between 0 and 2 pi;
and step S43, substituting the values of different heights of the antenna reflecting surface nodes into the corrected Davenport spectrum, and calculating the wind speed samples of any nodes at different heights.
6. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 1, wherein the step S6 comprises the steps of:
step S61, calculating the wind pressure coefficient of any node of the antenna reflecting surface by using a wind tunnel test and a planar linear interpolation method;
step S62, calculating the area of the wind pressure at any node on the antenna panel;
and step S63, calculating the wind pressure received by any node of the antenna panel according to the pulsating wind speed sample calculated in the step S4, the wind pressure coefficient obtained in the step S61 and the wind pressure receiving area of any node obtained in the step S62.
And step S64, according to the antenna reflecting surface unit information, combining the wind pressure received by any node of the antenna panel calculated in the step S63 with a finite element operation command in finite element analysis software to obtain a wind pressure file directly applied to an antenna model.
7. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 6, wherein the step S61 comprises:
step S611, measuring a wind pressure coefficient of a specific node of the antenna reflecting surface by using a wind tunnel experiment;
and step S612, if the node coordinates do not coincide with the coordinates of the measuring points of the wind tunnel experiment, performing interpolation according to the wind pressure coefficients of the measuring points of the wind tunnel experiment to obtain the wind pressure coefficient of the antenna net panel.
8. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 7, wherein the wind pressure coefficient C of the antenna net panelΔPmeshComprises the following steps:
Figure FDA0002572597140000031
wherein, CΔPsolidIs the wind pressure coefficient of the antenna real panel; cDmeshAnd CDsolidThe wind pressure coefficients of the common net surface flat plate and the common solid surface flat plate are obtained through a wind tunnel test.
9. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 6, wherein the wind pressure area at any node in the step S62 is composed of four panel parts around the node.
10. The method for rapidly measuring and calculating the pulsating wind pressure of the antenna panel of the large-scale radio telescope according to claim 6, wherein the wind pressure P suffered by any node of the antenna panel isd(t) is:
Figure FDA0002572597140000032
where v (t) is the random pulsating wind speed at any node on the antenna reflection surface calculated in step S4, ρ is the air density, and CdPIs the wind pressure coefficient on the reflecting surface of the node, Ad1The area of the node corresponding to the wind pressure is obtained.
CN202010644727.9A 2020-07-07 2020-07-07 Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope Pending CN112001099A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010644727.9A CN112001099A (en) 2020-07-07 2020-07-07 Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010644727.9A CN112001099A (en) 2020-07-07 2020-07-07 Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope

Publications (1)

Publication Number Publication Date
CN112001099A true CN112001099A (en) 2020-11-27

Family

ID=73467361

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010644727.9A Pending CN112001099A (en) 2020-07-07 2020-07-07 Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope

Country Status (1)

Country Link
CN (1) CN112001099A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112950784A (en) * 2021-04-12 2021-06-11 中国科学院国家天文台 Observation environment analysis method for ground-based optical astronomical station
SE2150321A1 (en) * 2021-03-19 2022-09-20 Mafi Ab Method and system for bracket configuration

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0650839A (en) * 1991-02-07 1994-02-25 Shimizu Corp System for analyzing dynamic response by wind external force
CN105354377A (en) * 2015-10-29 2016-02-24 中国电力科学研究院 Method for determining fluctuation wind induced vibration load of power transmission tower
CN106875488A (en) * 2017-01-12 2017-06-20 西安电子科技大学 A kind of reflecting plane aerial panel coefficient of wind pres method for numerical simulation

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0650839A (en) * 1991-02-07 1994-02-25 Shimizu Corp System for analyzing dynamic response by wind external force
CN105354377A (en) * 2015-10-29 2016-02-24 中国电力科学研究院 Method for determining fluctuation wind induced vibration load of power transmission tower
CN106875488A (en) * 2017-01-12 2017-06-20 西安电子科技大学 A kind of reflecting plane aerial panel coefficient of wind pres method for numerical simulation

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
张巨勇;施浒立;陈志平;张洪波;: "大口径天线结构随机风荷时域电性能的数值计算", 吉林大学学报(工学版), no. 05 *
张相庭: "结构风压和风振计算", 31 May 1985, 同济大学出版社, pages: 65 - 66 *
王从思: "天线机电热多场耦合理论与综合分析方法研究", 中国优秀博士学位论文全文数据库, vol. 2008, no. 04 *
王从思: "天线机电热多场耦合理论与综合分析方法研究", 中国博士学位论文全文数据库(信息科技辑), vol. 2008, no. 04, pages 136 - 2 *
雷飞: "大型面天线的结构性能仿真分析", 中国优秀硕士学位论文全文数据库(信息科技辑), vol. 2010, no. 11, pages 136 - 24 *
雷飞: "大型面天线的结构性能仿真分析", 中国优秀硕士学位论文全文数据库, vol. 2010, no. 11, pages 136 - 24 *
雷飞;: "大型面天线的瞬态风荷分析", 火控雷达技术, no. 04 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE2150321A1 (en) * 2021-03-19 2022-09-20 Mafi Ab Method and system for bracket configuration
SE544939C2 (en) * 2021-03-19 2023-01-10 Mafi Group AB Method and system for bracket configuration
CN112950784A (en) * 2021-04-12 2021-06-11 中国科学院国家天文台 Observation environment analysis method for ground-based optical astronomical station
CN112950784B (en) * 2021-04-12 2024-03-19 中国科学院国家天文台 Foundation optical astronomical station observation environment analysis method

Similar Documents

Publication Publication Date Title
Kepert Observed boundary layer wind structure and balance in the hurricane core. Part I: Hurricane Georges
Wang et al. A preliminary forecast for cosmological parameter estimation with gravitational-wave standard sirens from TianQin
EP3769091A1 (en) Wind flow sensing system and method for determining velocity fields of wind flow
Bierdel et al. Accuracy of rotational and divergent kinetic energy spectra diagnosed from flight-track winds
CN114357571B (en) Inversion method and system for wind field characteristics of atmospheric boundary layer under built building environment
JP7403690B2 (en) System and method for measuring high-speed wind flow with LiDAR in complex terrain
CN112001099A (en) Method for quickly measuring and calculating pulsating wind pressure of antenna panel of large radio telescope
Zhang et al. Analysis of reflector vibration-induced pointing errors for large antennas subject to wind disturbance: evaluating the pointing error caused by reflector deformation
JP2023517147A (en) Systems and methods for measuring wind flow turbulence with LiDAR in complex terrain
Zaroubi et al. Deprojection of galaxy cluster X-ray, Sunyaev-Zeldovich temperature decrement, and weak-lensing mass maps
CN110826224A (en) Method for determining spherical harmonic coefficient of small celestial body gravitational field based on gravitational acceleration
CN116522600A (en) Complex wind field wind speed simulation method, device, equipment and medium
US20150212207A1 (en) Method and system for generating a distance velocity azimuth display
CN111967203A (en) Semi-analytic half-numerical atmospheric boundary layer three-dimensional typhoon wind field modeling method
Olivares-Pulido et al. Markov chain Monte Carlo and the application to geodetic time series analysis
Hinkelman et al. A large-eddy simulation study of anisotropy in fair-weather cumulus cloud fields
Surry et al. Model studies of wind effects-a perspective on the problems of experimental technique and instrumentation
Liou Single radar recovery of cross-beam wind components using a modified moving frame of reference technique
Fan et al. A numerical rotating water tank can reproduce the Coriolis effect on the urban heat dome flow
Xiaoyong et al. Dynamical and microphysical retrieval from simulated Doppler radar observations using the 4DVAR assimilation technique
Lee et al. Distance velocity–azimuth display (DVAD)—New interpretation and analysis of Doppler velocity
Chester et al. Renormalized numerical simulation of flow over planar and non-planar fractal trees
Warsido Reducing uncertainties in estimation of wind effects on tall buildings using aerodynamic wind tunnel tests
Morrison et al. An assessment of turbulence profiles in rural and urban environments using local measurements and numerical weather prediction results
Kildal et al. Identification of aerodynamic admittance functions in active grid generated turbulent flow

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