[技術(shù)]十字元件熱成像分析 [復(fù)制鏈接]

首先在第一行輸入temperature :300K，emissivity: 0.1;

Target 元件距離坐標(biāo)原點(diǎn)-161mm;

探測(cè)器參數(shù)設(shè)定：

在菜單欄中選擇Create/Element Primitive /plane

元件半徑為20mm*20,mm,距離坐標(biāo)原點(diǎn)200mm。

光源創(chuàng)建：

光源類(lèi)型選擇為任意平面，光源半角設(shè)定為15度。

我們將光源設(shè)定在探測(cè)器位置上，具體的原理解釋請(qǐng)見(jiàn)本章第二部分。

我們?cè)谖恢眠x項(xiàng)又設(shè)定一行的目的是通過(guò)腳本自動(dòng)控制光源在探測(cè)器平面不同劃分區(qū)域內(nèi)不同位置處追跡光線(xiàn)。

功率數(shù)值設(shè)定為：P=sin2（theta） theta為光源半角15度。我們?yōu)槭裁匆�這么設(shè)定，在第二部分會(huì)給出詳細(xì)的公式推導(dǎo)。

創(chuàng)建分析面：

到這里元件參數(shù)設(shè)定完成，現(xiàn)在我們?cè)O(shè)定元件的光學(xué)屬性，在前面我們分別對(duì)第一和第二面設(shè)定的溫度和發(fā)射系數(shù)，散射屬性我們?cè)O(shè)定為黑朗伯，4%的散射。并分別賦予到面一和面二。

FRED具有一個(gè)內(nèi)置的可編譯的Basic腳本語(yǔ)言。從Visual Basic腳本語(yǔ)言里，幾乎所有用戶(hù)圖形界面（GUI）命令是可用這里的。FRED同樣具有自動(dòng)的客戶(hù)端和服務(wù)器能力，它可以被調(diào)用和并調(diào)用其他可啟動(dòng)程序，如Excel。因此可以在探測(cè)器像素點(diǎn)上定義多個(gè)離軸光源，及在FRED Basic腳本語(yǔ)言里的For Next loops語(yǔ)句沿著探測(cè)器像素點(diǎn)向上和向下掃描來(lái)反向追跡光線(xiàn),這樣可以使用三維圖表查看器(Tools/Open plot files in 3D chart)調(diào)用和查看數(shù)據(jù)。

將如下的代碼放置在樹(shù)形文件夾 Embedded Scripts，

綠色字體為說(shuō)明文字，

'#Language "WWB-COM"

'script for calculating thermal image map

'edited rnp 4 november 2005

'declarations

Dim op As T_OPERATION

Dim trm As T_TRIMVOLUME

Dim irrad(32,32) As Double 'make consistent with sampling

Dim temp As Double

Dim emiss As Double

Dim fname As String, fullfilepath As String

'Option Explicit

Sub Main

    'USER INPUTS

    nx = 31

    ny = 31

    numRays = 1000

    minWave = 7    'microns

    maxWave = 11   'microns

    sigma = 5.67e-14 'watts/mm^2/deg k^4

    fname = "teapotimage.dat"

    Print ""

    Print "THERMAL IMAGE CALCULATION"

    detnode = FindFullName( "Geometry.Detector.Surface" ) '找到探測(cè)器平面節(jié)點(diǎn)

    Print "found detector array at node " & detnode

    srcnode = FindFullName( "Optical Sources.Source 1" ) '找到光源節(jié)點(diǎn)

    Print "found differential detector area at node " & srcnode

    GetTrimVolume detnode, trm

    detx = trm.xSemiApe

    dety = trm.ySemiApe

    area = 4 * detx * dety

    Print "detector array semiaperture dimensions are " & detx & " by " & dety

    Print "sampling is " & nx & " by " & ny

    'reset differential detector area dimensions to be consistent with sampling

    pixelx = 2 * detx / nx

    pixely = 2 * dety / ny

    SetSourcePosGridRandom srcnode, pixelx / 2, pixely / 2, numRays, False

    Print "resetting source dimensions to " & pixelx / 2 & " by " & pixely / 2

    'reset the source power

    SetSourcePower( srcnode, Sin(DegToRad(15))^2 )

    Print "resetting the source power to " & GetSourcePower( srcnode ) & " units"

    'zero out irradiance array

    For i = 0 To ny - 1

        For j = 0 To nx - 1

            irrad(i,j) = 0.0

        Next j

    Next i

    'main loop

    EnableTextPrinting( False )

    ypos =  dety + pixely / 2

    For i = 0 To ny - 1

        xpos = -detx - pixelx / 2

        ypos = ypos - pixely

        EnableTextPrinting( True )

        Print i

        EnableTextPrinting( False )

        For j = 0 To nx - 1

            xpos = xpos + pixelx

            'shift source

            LockOperationUpdates srcnode, True

            GetOperation srcnode, 1, op

            op.val1 = xpos

            op.val2 = ypos

            SetOperation srcnode, 1, op

            LockOperationUpdates srcnode, False

'raytrace             DeleteRays             CreateSource srcnode             TraceExisting 'draw             'radiometry             For k = 0 To GetEntityCount()-1                 If IsSurface( k ) Then                     temp = AuxDataGetData( k, "temperature" )                     emiss = AuxDataGetData( k, "emissivity" )                     If ( temp <> 0 And emiss <> 0 ) Then                         ProjSolidAngleByPi = GetSurfIncidentPower( k )                         frac = BlackBodyFractionalEnergy ( minWave, maxWave, temp )                         irrad(i,j) = irrad(i,j) + frac * emiss * sigma * temp^4 * ProjSolidAngleByPi                     End If                 End If             Next k         Next j     Next i     EnableTextPrinting( True )     'write out file     fullfilepath = CurDir() & "\" & fname     Open fullfilepath For Output As #1     Print #1, "GRID " & nx & " " & ny     Print #1, "1e+308"     Print #1, pixelx & " " & pixely     Print #1, -detx+pixelx/2 & " " & -dety+pixely/2     maxRow = nx - 1     maxCol = ny - 1     For rowNum = 0 To maxRow                    ' begin loop over rows (constant X)             row = ""         For colNum = maxCol To 0 Step -1            ' begin loop over columns (constant Y)             row = row & irrad(colNum,rowNum) & " "     ' append column data to row string         Next colNum                     ' end loop over columns             Print #1, row     Next rowNum                         ' end loop over rows     Close #1     Print "File written: " & fullfilepath     Print "All done!!" End Sub 在輸出報(bào)告中，我們會(huì)看到腳本對(duì)光源的孔徑和功率做了修改，并最終經(jīng)過(guò)31次迭代，將所有的熱成像數(shù)據(jù)以dat的格式放置于： 找到Tools工具，點(diǎn)擊Open plot files in 3D chart并找到該文件    打開(kāi)后，選擇二維平面圖：