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Moin,
Ich habe folgende Iteration aber es führt keine Iteration. Doch rechnet er aber kein Convergence. Neben bei Falls es ein Iteration (If statement) schleife für Zielwertesuche gibt, teilen Sie hier bitte.
Function Do_FDBR_9_4_5_4(Zeta_soll As Double, D_1_mm As Double, D_2_mm As Double, R_kante_mm As Double)
Dim Pi As Double, A1 As Double, Ao As Double, A2 As Double, m1 As Double, m2 As Double, D_h As Double, Zeta_Strich As Double, D_o_mm As Double, Zeta_cal As Double, X As Double
For D_o_mm = 0.01 * D_2_mm To D_2_mm Step 0.1
Pi = 3.14
A1 = (Pi / 4) * (D_1_mm / 1000) ^ 2
Ao = (Pi / 4) * (D_o_mm / 1000) ^ 2
A2 = (Pi / 4) * (D_2_mm / 1000) ^ 2
m1 = Ao / A1
m2 = Ao / A2
D_h = 4 * Ao / (Pi * D_o_mm / 1000)
Zeta_Strich = 0.5 - 0.47 * tanh(13.9 * R_kante_mm * 0.001 / D_h)
Zeta_cal = ((Zeta_Strich * (1 - m1)) ^ 0.5 + (1 - m2)) ^ 2 * (1 / m2) ^ 2
X = Abs(Zeta_soll - Zeta_cal) / Zeta_soll
If X < 0.001 Then
Do_FDBR_9_4_5_4 = D_o_mm
Exit For
Else
GoTo Iteration
End If
Iteration:
Next
End Function
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