104
ɉɨ ɷɬɨɣ ɮɨɪɦɭɥɟ ɧɚ ɪɢɫ. 3.6 ɩɨɫɬɪɨɟɧɚ ɧɚɤɥɨɧɧɚɹ ɧɢɠɧɹɹ ɩɪɹɦɚɹ,
ɨɩɢɫɵɜɚɸɳɚɹ ɨɛɥɚɫɬɶ ɝɥɚɞɤɢɯ ɬɪɭɛ ɞɨ Re = 10
5
. ɉɨɞɫɬɚɜɥɹɹ ɜɵɪɚɠɟɧɢɟ
ɞɥɹ
O
ɜ ɮɨɪɦɭɥɭ (3.6) ɦɨɠɧɨ ɩɨɤɚɡɚɬɶ, ɱɬɨ ɜ ɷɬɨɣ ɨɛɥɚɫɬɢ h
ɞ
~ V
1.75
.
ɋ ɭɜɟɥɢɱɟɧɢɟɦ ɱɢɫɥɚ Ɋɟɣɧɨɥɶɞɫɚ, ɧɚɩɪɢɦɟɪ, ɡɚ ɫɱɟɬ ɩɨɜɵɲɟɧɢɹ
ɫɤɨɪɨɫɬɢ ɬɟɱɟɧɢɹ, ɬɨɥɳɢɧɚ ɥɚɦɢɧɚɪɧɨɝɨ ɩɨɞɫɥɨɹ ɬɭɪɛɭɥɟɧɬɧɨɝɨ ɩɨɬɨɤɚ
ɭɦɟɧɶɲɚɟɬɫɹ ɢ ɩɪɢ
Re 10d!' ɜɵɫɬɭɩɵ ɲɟɪɨɯɨɜɚɬɨɫɬɢ ɨɝɨɥɹɸɬɫɹ. Ɉɧɢ
ɧɚɱɢɧɚɸɬ ɜɧɨɫɢɬɶ ɞɨɩɨɥɧɢɬɟɥɶɧɵɟ ɜɨɡɦɭɳɟɧɢɹ (ɜɢɯɪɢ) ɜ ɬɭɪɛɭɥɟɧɬɧɨɟ
ɹɞɪɨ ɩɨɬɨɤɚ, ɱɬɨ ɩɪɢɜɨɞɢɬ ɤ ɜɨɡɪɚɫɬɚɧɢɸ ɩɨɬɟɪɶ ɧɚɩɨɪɚ; ɜ ɷɬɨɦ ɫɥɭɱɚɟ
ɬɪɭɛɚ (ɫɬɟɧɤɚ) ɧɚɡɵɜɚɟɬɫɹ ɝɢɞɪɚɜɥɢɱɟɫɤɢ ɲɟɪɨɯɨɜɚɬɨɣ. Ɉɛɥɚɫɬɶ ɲɟɪɨ-
ɯɨɜɚɬɵɯ ɬɪɭɛ ɩɪɟɞɫɬɚɜɥɟɧɚ ɧɚ ɝɪɚɮɢɤɟ ɫɟɦɟɣɫɬɜɨɦ ɤɪɢɜɵɯ, ɧɚɯɨɞɹɳɢɯ-
ɫɹ ɩɪɚɜɟɟ ɥɢɧɢɢ ɝɥɚɞɤɢɯ ɬɪɭɛ ɢ ɨɩɢɫɵɜɚɟɦɵɯ ɮɨɪɦɭɥɨɣ Ⱥ.Ⱦ. Ⱥɥɶɬɲɭɥɹ
0,25
68
0,11
Re d
O
'
§·
¨¸
©¹
.
Ɏɨɪɦɭɥɚ ɭɤɚɡɵɜɚɟɬ ɧɚ ɭɜɟɥɢɱɟɧɢɟ ɤɨɷɮɮɢɰɢɟɧɬɚ ɬɪɟɧɢɹ O ɫ ɜɨɡ-
ɪɚɫɬɚɧɢɟɦ ɨɬɧɨɫɢɬɟɥɶɧɨɣ ɲɟɪɨɯɨɜɚɬɨɫɬɢ
d' ɫɬɟɧɨɤ. ɉɪɢ ɞɨɫɬɚɬɨɱɧɨ
ɛɨɥɶɲɢɯ ɱɢɫɥɚɯ Ɋɟɣɧɨɥɶɞɫɚ
Re of, ɤɨɝɞɚ ɩɪɚɤɬɢɱɟɫɤɢ ɨɬɫɭɬɫɬɜɭɟɬ
ɥɚɦɢɧɚɪɧɵɣ ɩɨɞɫɥɨɣ, ɤɨɷɮɮɢɰɢɟɧɬ O ɧɟ ɡɚɜɢɫɢɬ ɨɬ Re. Ɉɧ ɨɩɪɟɞɟɥɹɟɬɫɹ
ɥɢɲɶ ɨɬɧɨɫɢɬɟɥɶɧɨɣ ɲɟɪɨɯɨɜɚɬɨɫɬɶɸ
d' ɫɬɟɧɨɤ ɢ ɩɨɷɬɨɦɭ ɤɪɢɜɵɟ
ɝɪɚɮɢɤɚ ɩɟɪɟɯɨɞɹɬ ɜ ɝɨɪɢɡɨɧɬɚɥɶɧɵɟ ɩɪɹɦɵɟ, ɚ ɩɨɬɟɪɢ ɧɚɩɨɪɚ ɩɨ ɞɥɢɧɟ
ɫɬɚɧɨɜɹɬɫɹ ɩɪɨɩɨɪɰɢɨɧɚɥɶɧɵɦɢ ɤɜɚɞɪɚɬɭ ɫɪɟɞɧɟɣ ɫɤɨɪɨɫɬɢ (h
ɞ
~V
2
). ɗɬɭ
ɱɚɫɬɶ ɨɛɥɚɫɬɢ ɲɟɪɨɯɨɜɚɬɵɯ ɬɪɭɛ ɧɚɡɵɜɚɸɬ ɡɨɧɨɣ ɤɜɚɞɪɚɬɢɱɧɨɝɨ ɫɨɩɪɨ-
ɬɢɜɥɟɧɢɹ.
ɂɬɚɤ, ɞɥɹ ɜɵɱɢɫɥɟɧɢɹ ɩɨɬɟɪɶ ɧɚɩɨɪɚ ɩɨ ɞɥɢɧɟ ɧɟɨɛɯɨɞɢɦɨ ɩɪɟɞɜɚ-
ɪɢɬɟɥɶɧɨ ɜɵɹɜɢɬɶ ɨɛɥɚɫɬɶ ɫɨɩɪɨɬɢɜɥɟɧɢɹ (ɨɛɥɚɫɬɶ ɥɚɦɢɧɚɪɧɨɝɨ ɞɜɢɠɟ-
ɧɢɹ, ɨɛɥɚɫɬɶ ɝɥɚɞɤɢɯ ɢɥɢ ɨɛɥɚɫɬɶ ɲɟɪɨɯɨɜɚɬɵɯ ɫɬɟɧɨɤ ɬɭɪɛɭɥɟɧɬɧɨɝɨ
ɞɜɢɠɟɧɢɹ), ɚ ɡɚɬɟɦ ɨɩɪɟɞɟɥɹɬɶ ɤɨɷɮɮɢɰɢɟɧɬ ɬɪɟɧɢɹ ɩɨ ɫɨɨɬɜɟɬɫɬɜɭɸ-
ɳɢɦ ɷɬɢɦ ɨɛɥɚɫɬɹɦ ɮɨɪɦɭɥɚɦ. ɉɨɬɟɪɢ ɧɚɩɨɪɚ ɜ ɬɪɭɛɚɯ
ɧɟɤɪɭɝɥɨɝɨ ɫɟ-
ɱɟɧɢɹ ɦɨɠɧɨ ɨɩɪɟɞɟɥɹɬɶ ɩɨ ɮɨɪɦɭɥɚɦ ɞɥɹ ɤɪɭɝɥɵɯ ɬɪɭɛ, ɩɨɞɫɬɚɜɥɹɹ ɜ
ɧɢɯ ɜɦɟɫɬɨ ɝɟɨɦɟɬɪɢɱɟɫɤɨɝɨ ɝɢɞɪɚɜɥɢɱɟɫɤɢɣ ɞɢɚɦɟɬɪ d = d
ɝ
.
ȼɵɲɟɩɪɢɜɟɞɟɧɧɵɟ ɮɨɪɦɭɥɵ ɩɪɢɝɨɞɧɵ ɞɥɹ ɜɵɱɢɫɥɟɧɢɹ ɤɨɷɮɮɢɰɢ-
ɟɧɬɚ ɬɪɟɧɢɹ ɩɪɢ ɪɚɜɧɨɦɟɪɧɨɦ ɬɟɱɟɧɢɢ, ɤɨɬɨɪɨɟ ɭɫɬɚɧɚɜɥɢɜɚɟɬɫɹ ɜ ɬɪɭɛɟ
(ɤɚɧɚɥɟ) ɩɨɫɬɨɹɧɧɨɝɨ ɫɟɱɟɧɢɹ ɧɚ ɧɟɤɨɬɨɪɨɦ ɪɚɫɫɬɨɹɧɢɢ ɨɬ ɜɯɨɞɚ. ɍɱɚ-
ɫɬɨɤ, ɩɪɟɞɲɟɫɬɜɭɸɳɢɣ ɧɚɫɬɭɩɥɟɧɢɸ ɪɚɜɧɨɦɟɪɧɨɝɨ ɞɜɢɠɟɧɢɹ ɠɢɞɤɨ-
ɫɬɢ, ɧɚɡɵɜɚɟɬɫɹ ɧɚɱɚɥɶɧɵɦ (ɪɚɡɝɨɧɧɵɦ). Ɉɧ ɯɚɪɚɤɬɟɪɢɡɭɟɬɫɹ ɩɨɜɵɲɟɧ-
ɧɵɦɢ ɩɨɬɟɪɹɦɢ ɧɚɩɨɪɚ, ɱɬɨ ɨɛɴɹɫɧɹɟɬɫɹ ɧɟɪɚɜɧɨɦɟɪɧɨɫɬɶɸ ɬɟɱɟɧɢɹ ɢɡ-
ɡɚ ɢɡɦɟɧɟɧɢɹ ɷɩɸɪɵ ɫɤɨɪɨɫɬɟɣ (ɧɟɫɦɨɬɪɹ
ɧɚ ɩɨɫɬɨɹɧɫɬɜɨ ɫɪɟɞɧɟɣ ɫɤɨ-
ɪɨɫɬɢ) ɩɨ ɩɭɬɢ. Ɍɚɤ, ɧɚɩɪɢɦɟɪ, ɧɚ ɜɯɨɞɟ ɢɡ ɪɟɡɟɪɜɭɚɪɚ ɜ ɬɪɭɛɭ ɱɚɫɬɢɰɵ
ɠɢɞɤɨɫɬɢ ɢɦɟɸɬ ɨɞɢɧɚɤɨɜɭɸ ɩɨ ɫɟɱɟɧɢɸ ɫɤɨɪɨɫɬɶ, ɚ ɩɨ ɦɟɪɟ ɭɞɚɥɟɧɢɹ
ɨɬ ɜɯɨɞɚ ɡɚɦɟɞɥɹɸɬɫɹ ɭ ɫɬɟɧɨɤ ɢ ɭɫɤɨɪɹɸɬɫɹ ɧɚ ɨɫɢ ɩɨɬɨɤɚ.