传热学第四章课后习题 5(第五版)

一厚度为250mm无限大平壁，其导热系数为43+0.08t,平壁一侧温度为250摄氏度，另一侧温度为46摄氏度，试用vb程序求平壁内温度分布，并求通过该平壁的热流密度。





Private Sub Command1_Click()
Dim t(11) As Single, q(11) As Single, q1 As Single, tt As Double, ttt As Double, i As Long, a As Double, b As Double
t(1) = 250
t(11) = 46
ttt = 0.1

Do
tt = t(5)
For i = 2 To 10
a = 43 + 0.08 * (t(i - 1) + t(i)) / 2
b = 43 + 0.08 * (t(i) + t(i + 1)) / 2
t(i) = (a * t(i - 1) + b * t(i + 1)) / (a + b)
Next i
ttt = Abs(t(5) - tt)
Loop Until ttt < 0.01
Print "温度分布" & "："
For i = 1 To 11
Print t(i)
Next i
For i = 2 To 11
a = 43 + 0.08 * (t(i - 1) + t(i)) / 2
q(i) = q(i - 1) + a * (t(i) - t(i - 1))
q1 = q(i) / 0.25
Next i
Print "热流密度" & ";" & q1
End Sub