praktikum_meh_gidk_gaz_01

52

]^_ O – dhwnnbpb_gl ]b^jZ\ebq_kdh]h lj_gby beb dhwnnbpb_gl >Zjkb ([_ajZaf_jguc); Re – qbkeh J_cghev^kZ; l b d– ^ebgZ b ^bZf_lj ljm[hijh\h^Z; V – kj_^gyy kdhjhklv ihlhdZ; g – mkdhj_gb_ k\h[h^gh]h iZ^_gby.

>ey hij_^_e_gby dhwnnbpb_glZ O ij_^eh`_g jy^ nhjfme, mqblu-

\Zxsbo _]h aZ\bkbfhklv hl qbkeZ J_cghev^kZ, r_jhoh\Zlhklb, jZaf_jh\ ihi_j_qgh]h k_q_gby ljm[.

bkdmkkl\_gghc r_j_oh\Zlhklvx, [ueh mklZgh\e_gh kms_kl\h\Zgb_ q_luj_o hkgh\guo ahg khijhlb\e_gbc , dZ`^Zy ba dhlhjuo oZjZdl_jbam_lky k\hbfb

aZ\bkbfhklyfb O = g(Re, ' ). < h[s_f kemqZ_ O aZ\bkbl hl qbkeZ J_cghev^kZ

d

b r_jhoh\Zlhklb kl_ghd ljm[u.

JZkkfhljbf [he__ ih^jh[gh dZ`^mx ba wlbo ahg.

1-y ahgZ – ahgZ \yadh]h khijhlb\e_gby. HgZ ho\Zlu\Z_l eZfbgZjguc j_`bf ^\b`_gby. Ij_^_eu wlhc ahgu ih qbkem J_cghev^kZ – Re < 2320.

Dhwnnbpb_gl O aZ\bkbl lhevdh hl qbkeZ Re b hij_^_ey_lky ^ey ljm[ djm]eh]h k_q_gby ih aZdhgm ImZa_cey

Ih^klZ\eyy wlh agZq_gb_ \ nhjfmem (6.1),ihemqbf

Lhqg__ iylb ahg khijhlb\e_gbc, gh i_j_oh^gZy ahgZ hl eZfbgZjgh]h j_`bfZ ^\b`_gby d lmj[me_glghfm g_ bf__l hkh[h]h ijZdlbq_kdh]h agZq_gby

53

A^_kv b gb`_ k – dhwnnbpb_gl ijhihjpbhgZevghklb. Hlkx^Z \b^gh,

qlh ihl_jb gZihjZ ijb eZfbgZjghf j_`bf_ ijyfh ijhihjpbhgZevgu kj_^g_c kdhjhklb \ i_j\hc kl_i_gb.

Ijb lmj[me_glghf j_`bf_, kljmdlmjZ dhlhjh]h hibkZgZ \ur_, ihl_jb gZihjZ fh]ml kbevgh f_gylvky \ aZ\bkbfhklb hl ^bZf_ljZ ljm[u, kdhjhklb ^\b`_gby, \yadhklb `b^dhklb b r_jhoh\Zlhklb kl_ghd ljm[u. >ey

dhebq_kl\_gghc hp_gdb r_jhoh\Zlhklb \\h^blky ihgylb_ h kj_^g_c \ukhl_

\uklmih\ r_jhoh\Zlhklb. Wlm \ukhlm gZau\Zxl Z[khexlghc r_jhoh\Zlhklvx – '.

Ijb h^ghc b lhc `_ \_ebqbg_ Z[khexlghc r_jhoh\Zlhklb __ \ebygb_ gZ \_ebqbgm ]b^jZ\ebq_kdbo khijhlb\e_gbc jZaebqgh \ aZ\bkbfhklb hl

^bZf_ljZ ljm[u. Ihwlhfm \\h^blky ihgylb_ hlghkbl_evghc

r_jhoh\Zlhklb, jZ\ghc hlghr_gbx Z[khexlghc r_jhoh\Zlhklb d ^bZf_ljm

(beb jZ^bmkm) ljm[u, l._. \_ebqbgZ ' beb ( ' ). < k\yab k l_f, qlh Z[khexlgZy

dr

r_jhoh\Zlhklv bf__l jZaebqgu_ ih \ukhl_ b ih iehsZ^b dhwnnbpb_gl O gZqbgZ_l jZkijhkljZg_gby \uklmiu, Z baf_jblv bo \_ebqbgm ijZdlbq_kdb g_\hafh`gh, lh \ ijZdlbdm ]b^jZ\ebq_kdbo jZkq_lh\ [ueh \\_^_gh ihgylb_ wd\b\Ze_glghc r_jhoh\Zlhklb - 'wd\. Ih^ wd\b\Ze_glghc r_jhoh\Zlhklvx

'wd\ ihgbfZxl lZdmx \ukhlm \uklmih\ r_jhoh\Zlhklb, keh`_gghc ba i_kqbghd h^bgZdh\h]h jZaf_jZ, dhlhjZy ^Z_l ijb wdki_jbf_glZo h^bgZdh\mx k _kl_kl\_gghc Z[khexlghc r_jhoh\Zlhklvx \_ebqbgm dhwnnbpb_glZ ]b^jZ\ebq_kdh]h lj_gby.

Ijb lmj[me_glghf j_`bf_ \ aZ\bkbfhklb hl khhlghr_gby jZaf_jh\ eZfbgZjgh]h ih^kehy G gZ kl_gd_ ljm[u b \ukhlu \uklmih\ Z[khexlghc r_jhoh\Zlhklb ', jZaebqZxl ljm[u ]b^jZ\ebq_kdb ]eZ^db_ (G² ') b

]b^jZ\ebq_kdb r_jhoh\Zlu_ (G ¢ ' ).

< h[eZklb ]b^jZ\ebq_kdb ]eZ^dbo ljm[ ijb

54

bf__l f_klh

2-y ahgZ – ]eZ^dhkl_ggh]h khijhlb\e_gby. < wlhc ahg_ ijbkl_gguc

kehc, lhesbgZ dhlhjh]h (G) [hevr_ r_jhoh\Zlhklb ('), bf__l kljmdlmjm eZfbgZjgh]h l_q_gby. Hg dZd [u bahebjm_l lmj[me_glgh_ y^jh hl dhglZdlZ k r_jhoh\Zlhklvx, ihwlhfm dhwnnbpb_gl khijhlb\e_gby O aZ\bkbl lhevdh hl

K m\_ebq_gb_f kdhjhklb ihlhdZ lhesbgZ ijbkl_ggh]h eZfbgZjgh]h kehy mf_gvrZ_lky b, dh]^Z G klZg_l ijbf_jgh jZ\guf ', gZklmiZ_l

3-y ahgZ – i_j_oh^gZy hl ]eZ^dhkl_ggh]h khijhlb\e_gby d d\Z^jZlbqghfm (^hd\Z^jZlbqgZy ahgZ), \ dhlhjhc gZ dhwnnbpb_gl hdZau\Z_l \ebygb_ ^\Z nZdlhjZ: qbkeh J_cghev^kZ b hlghkbl_evgZy r_jhoh\Zlhklv, l._.

r_jhoh\Zluf, ]jZgbpu dhlhjhc hij_^_eyxl qbkeZ J_cghev^kZ, gZoh^ysb_ky \ ke_^mxs_f ^bZiZahg_ agZq_gbc

55

>ey hij_^_e_gby O \ wlhc ahg_ fh`_l [ulv j_dhf_g^h\ZgZ nhjfmehc

:.>. :evlrmey

>Zevg_cr__ m\_ebq_gb_ kdhjhklb ihlhdZ ihqlb iheghklvx h]hey_l \uklmiu r_jhoh\Zlhklb, \ j_amevlZl_ q_]h eZfbgZjguc ih^kehc bkq_aZ_l b ijbkl_gguc kehc klZgh\blky \boj_\uf. LZdhfm l_q_gbx khhl\_lkl\m_l

4-y ahgZ – d\Z^jZlbqgh]h khijhlb\e_gby beb ahgZ ]b^jZ\ebq_kdb r_jhoh\Zluo ljm[, ijb dhlhjhc \ebygb_f \yadhklb `b^dhklb gZ \_ebqbgm khijhlb\e_gby fh`gh ij_g_[j_qv, Z wlh agZqbl, qlh dhwnnbpb_gl O [m^_l

h^e k V 2,0 GZqZeh wlhc ahgu ih qbkem J_cghev^kZ hij_^_ey_lky mkeh\b_f

Dhwnnbpb_gl O \ wlhc ahg_ fh`gh hij_^_eblv ih nhjfme_ ;.E. Rbn-

jbgkhgZ

56

< mq_[gbdZo, kijZ\hqgbdZo b ^jm]hc ebl_jZlmj_ ^ey dZ`^hc ahgu khijhlb\e_gby ij_^eZ]Z_lky g_ h^gZ, Z g_kdhevdh wfibjbq_kdbo nhjfme ^ey hij_^_e_gby dhwnnbpb_glZ >Zjkb. ?keb d wlhfm ^h[Z\blv, qlh ijb \uiheg_gbb jZkq_lZ ihl_jv ih ^ebg_, dZ`^Zy lZdZy nhjfmeZ g_ fh`_l mq_klv j_Zevgh]h khklhygby ih\_joghklb kl_ghd b mkeh\bc wdkiemZlZpbb ljm[hijh\h^h\, lh \iheg_ ^himklbfh ^ey \k_o ahg khijhlb\e_gby bkihevah\Zlv, k khhl\_lkl\mxs_c dhjj_dpb_c, dhf[bgbjh\Zggmx nhjfmem :evlrmey (6.6):

O§ 68 '·0.25

0.11¨ ¸ . ©Re ¹d

Mgb\_jkZevghklv wlhc nhjfmeu klZgh\blky hq_\b^ghc, _keb ij_^klZ\blv __ \ ke_^mxs_f \b^_:

]^_ : - i_j\h_ keZ]Z_fh_ \ kdh[dZo hl\_qZ_l aZ ahgm ]eZ^dhkl_ggh]h khijhlb\e_gby, < - \lhjh_ – aZ r_jhoh\Zlmx ahgm, Z bo kmffZ – aZ i_j_oh^gmx.

Ih^\h^y blh]b, knhjfmebjm_f ihke_^h\Zl_evghklv ^_ckl\bc, dhlhjufb ke_^m_l jmdh\h^kl\h\Zlvky, \uihegyy bg`_g_jgu_ jZkq_lu ihl_jv ih ^ebg_ \ ljm[hijh\h^Zo:

1. Hij_^_ey_lky qbkeh J_cghev^kZ (Re=Vd/Q).

?keb ihemq_ggh_ agZq_gb_ Re < 2320, lh j_`bf ^\b`_gby eZfbgZjguc b dhwnnbpb_gl >Zjkb jZkkqblu\Z_lky ih nhjfme_ (6.2).

57

Ijb Re > 2320 – bf__l f_klh lmj[me_glgh_ l_q_gb_, ijbq_f kh kljmdlmjhc, khhl\_lkl\mxs_c h^ghc ba lj_o mdZaZgguo ahg khijhlb\e_gby.

>ey jZkq_lZ dhwnnbpb_glZ \u[bjZxlky nhjfmeu 6.4, 6.6, 6.8.

Mijhklblv ihke_^h\Zl_evghklv jZkq_lguo ^_ckl\bc iha\hey_l ko_fZ, ijb\_^_ggZy \ lZ[ebp_ 6.1.

GZ qbkeh\hc hkb J_cghev^kZ bf_xlky hlf_ldb, jZa]jZgbqb\Zxsb_, \h- i_j\uo, j_`bfu ^\b`_gby (hlf_ldZ 2320) b, \h-\lhjuo, ijb lmj[me_glghf j_`bf_ – ahgu khijhlb\e_gby (hlf_ldb 10d/' b 500d/'), agZq_gby dhlhjuo g_h[oh^bfh \uqbkeblv. >Ze__, ih ba\_klghfm agZq_gbx qbkeZ J_cghev^kZ, ihemq_gghfm ijb jZkq_l_ ihl_jv ih ^ebg_, gZoh^bf klhe[_p k khhl\_lkl\mxs_c ahghc khijhlb\e_gby, \ dhlhjhf gb`_ hkb J_cghev^kZ mdZaZgu hkgh\gu_ nbabq_kdb_ iZjZf_lju wlhc ahgu b ijb\_^_gZ nhjfmeZ ^ey hij_^_e_gby dhwnnbpb_glZ >Zjkb k __ Z\lhjhf.

>ey ihemq_gby hiulgh]h agZq_gby dhwnnbpb_glZ >Zjkb [m^_f bkihevah\Zlv nhjfmem (6.1):

58

– agZq_gb_ ihl_jv wg_j]bb ih ^ebg_, ihemq_ggh_ gZ wdki_jbf_glZevghc mklZgh\d_, hibkZgb_ dhlhjhc ijb\_^_gh gb`_.

HIBK:GB? HIULGHC MKL:GH<DB

IjbgpbibZevgZy ko_fZ wdki_jbf_glZevgh]h mqZkldZ ]hjbahglZevgh]h ljm[hijh\h^Z ihklhyggh]h k_q_gby, bkihevam_fh]h ^ey hij_^_e_gby dhwnnbpb_glZ , ijb\_^_gZ gZ jbk.6.1.

Jbk. 6.1

Hkgh\gufb we_f_glZfb wdki_jbf_glZevghc mklZgh\db y\eyxlky: gZihjguc [Zd ^ey iblZgby mklZgh\db \h^hc (gZ jbkmgd_ g_ ihdZaZg), hiulguc mqZklhd ljm[hijh\h^Z ihklhyggh]h ^bZf_ljZ b mkljhckl\h ^ey baf_j_gby jZkoh^Z. < kemqZ_ bkihevah\Zgby wdki_jbf_glZevghc mklZgh\db, hibkZgghc \ jZ[hl_ 4, iblZgb_ hkms_kl\ey_lky ih hldjulhfm pbjdmeypbhgghfm pbdem k aZ[hjhf \h^u ba \h^hh[hjhlgh]h [Zkk_cgZ \ gZihjguc [Zd, ihke_^mxsbf ^\b`_gb_f \h^u ih hiulghfm mqZkldm

59

ljm[hijh\h^Z, f_jghfm mkljhckl\m ^ey hij_^_e_gby jZkoh^Z b \ha\jZs_gb_f \h^u \ lhl `_ \h^hh[hjhlguc [Zkk_cg (kf. jbk. 4.2).

Hiulguc mqZklhd ljm[hijh\h^Z 1 (jbk. 6.1) ^he`_g [ulv kh\_jr_ggh ijyfuf b bf_lv ^ebgm l g_ f_g__ 100d, qlh[u bkdexqblv \hafh`gh_ \ebygb_ jZaebqguo f_klguo hkh[_gghkl_c (gZjmr_gb_ nhjfu, jZaf_jh\, jZaebqb_ \ r_jhoh\Zlhklb kl_ghd b l.i.). >ey mkljZg_gby \ebygby gZqZevgh]h mqZkldZ gZ j_amevlZlu hiulh\, gZqZeh hiulgh]h mqZkldZ ljm[hijh\h^Z ^he`gh [ulv m^Ze_gh hl \oh^Z \ ljm[hijh\h^ gZ jZkklhygb_ g_ f_g__ 50d. < gZqZevghf b dhg_qghf k_q_gbyo hiulgh]h mqZkldZ mklZgZ\eb\Zxlky iv_ahf_lju ‹ 1 b ‹ 2 (beb ^Zlqbdb ^bnn_j_gpbZevgh]h iv_ahf_ljZ), jZkklhygb_ f_`^m dhlhjufb bf__l ^ebgm L hiulgh]h mqZkldZ. < p_eyo [he__ lhqgh]h baf_j_gby kj_^g_]h ih k_q_gbx ]b^jh^bgZfbq_kdh]h ^Z\e_gby hl[hj ^Z\e_gbc ijhba\h^blky gZ kl_gdZo \ 4 – 6 lhqdZo ih i_jbf_ljm. Ljm[db hl[hjZ ^Z\e_gby h[t_^bgyxlky \ dhee_dlhj, k\yaZgguc k khhl\_lkl\mxsbf iv_ahf_ljhf. GZ ljm[hijh\h^_, kh_^bgyxs_f hiulguc mqZklhd k f_jguf mkljhckl\hf, mklZgZ\eb\Zxlky \_glbev 2 ^ey j_]mebjh\Zgby jZkoh^Z \ ljm[hijh\h^_ b l_jfhf_lj 3 ^ey baf_j_gby l_fi_jZlmju \h^u.

< dZq_kl\_ f_jgh]h mkljhckl\Z ^ey hij_^_e_gby jZkoh^Z fh`_l kem`blv lhgdhkl_gguc lj_m]hevguc \h^hkeb\ LhfkhgZ (kf. jZ[hlm 4) beb f_jguc [Zd.

IHJY>HD <UIHEG?GBY J:;HLU

1. Ihke_ \dexq_gby gZkhkZ, ih^Zxs_]h \h^m \ gZihjguc [Zd, hldju\Z_lky \_glbev 2 gZ ljm[hijh\h^_, [eZ]h^Zjy q_fm, \ kbkl_f_ mklZgZ\eb\Z_lky pbjdmeypby g_dhlhjh]h jZkoh^Z \h^u.

2.Ijhba\h^blky ijheb\dZ kh_^bgbl_evguo ljm[hd iv_ahf_ljh\ ^h ihegh]h m^Ze_gby ba gbo \ha^moZ, ^ey q_]h hldju\Zxlky khhl\_lkl\mxsb_ djZgu (gZ jbk. 6.1 djZgu g_ ihdZaZgu).

3.AZdju\Z_lky \_glbev 2 b ijh\_jyxlky "gmeb" iv_ahf_ljh\.

61

h^e= p1 p2 ,

Ug

l._. hiulgu_ ihl_jb gZihjZ h^e hij_^_eyxlky dZd jZaghklv ihdZaZgbc iv_ahf_ljh\ ‹ 1 b ‹ 2.

4. Ih nhjfme_ >Zjkb-<_ck[ZoZ (6.10) hij_^_ey_lky wdki_jbf_glZevgh_ agZq_gb_ dhwnnbpb_glZ :

=2g d h^e . l V 2

5. <uqbkey_lky qbkeh J_cghev^kZ Re =VdQ b ih _]h \_ebqbg_

hij_^_ey_lky j_`bf ^\b`_gby.

6. <uqbkey_lky wd\b\Ze_glgZy Z[khexlgZy r_jhoh\Zlhklv ûw hiulgh]h mqZkldZ ljm[hijh\h^Z. >ey wlh]h wdki_jbf_glZevgh_ agZq_gb_ dhwnnbpb_glZ \ d\Z^jZlbqghc h[eZklb khijhlb\e_gby (l._. ^ey hiulh\ kh kj_^g_c kdhjhklvx \h^u V •1,2 f/k) ih^klZ\ey_lky \ nhjfmem (6.8).

7.Kh]eZkgh g_jZ\_gkl\Zf (6.3), (6.5) b (6.7), hij_^_ey_lky h[eZklv khijhlb\e_gby ^\b`_gbx \h^u \ ljm[hijh\h^_ ijb lmj[me_glghf j_`bf_ iml_f kjZ\g_gby hiulgh]h agZq_gby qbkeZ J_cghev^kZ k \_ebqbghc hlghkbl_evghc ]eZ^dhklb d/ûw.

8.< aZ\bkbfhklb hl j_`bfZ ^\b`_gby b h[eZklb khijhlb\e_gby ih khhl\_lkl\mxsbf nhjfmeZf \uqbkey_lky \_ebqbgZ dhwnnbpb_glZ ]b^jZ\ebq_kdh]h lj_gby b kjZ\gb\Z_lky k _]h wdki_jbf_glZevguf agZq_gb_f. < d\Z^jZlbqghc h[eZklb khijhlb\e_gby dhwnnbpb_gl \uqbkey_lky ih nhjfme_ (6.8).

J_amevlZlu \uqbke_gbc k\h^ylky \ lZ[ebpm 6.2.