Gịnị bụ viscosity? viscosity n'ihe unit

Viscosity akọwa ike nke dị mmiri mmiri ma ọ bụ gas ike iguzogide n'etiti akpụ akpụ ikwu onye ọ bụla ọzọ n'ígwé nke ọmụmụ (bụghị siri ike) ozu. Nke ahụ bụ, a bara uru kwekọrọ na ike nke esịtidem esemokwu (English okwu: viscosity), ewepụtara ije nke gas ma ọ bụ mmiri mmiri. N'ihi na dị iche iche na ozu ya ga-adị iche, dị ka ọ na-adabere na ha agwa. Ka ihe atụ, mmiri nwere a ala viscosity tụnyere na mmanụ aṅụ, nke bụ nnọọ elu viscosity. The esịtidem esemokwu ma ọ bụ fluidity siri ike (nnukwu) ihe onwunwe e ji rheological e ji mara.

Okwu viscosity na-abịa site Latin Viscum, nke pụtara na mistletoe. Nke a bụ n'ihi na nnụnụ na-lime, nke na-mere si mistletoe tomato ma na-eji maka akụta nnụnụ. Nyagide tee na alaka osisi na nnụnụ ọdụ na ha, ghọrọ mfe eri anụ maka ụmụ mmadụ.

Gịnị bụ viscosity? Units ịtụ nke àgwà a ga-enye, dị ka bụ omenala, na SI usoro, nakwa dị ka ndị ọzọ na-abụghị SI nkeji.

Isaac Newton 1687, guzosie ike bụ isi iwu nke eruba nke mmiri mmiri na gaseous ozu: F = ƞ • {(v2 - bọmbụ V1) / (Z2 - Z1)} • S. Na nke a, F - bụ ike (tangential) nke na-akpata a mgbanwe nke ibughari n'ígwé ahu. The ruru (v2 - bọmbụ V1) / (Z2 - Z1) na-egosi na ọnụego nke mgbanwe nke mmiri mmiri ma ọ bụ gas eruba ike ọsọ na mgbanwe site otu oyi akwa ọzọ ibughari. Ma mara dị ka eruba ike ọsọ grajentị ma ọ bụ shiee ọnụego. The ịdị ukwuu nke S - bụ ebe (na cross ngalaba) nke ibughari ahụ oruru. Ƞ The proportionality na-akpata bụ ndị viscosity ọnụọgụ nke ike ahụ a. Size, ya inverse j = 1 / ƞ, a fluidity. Force dọgburu kwa unit ebe (na cross ngalaba) nke eruba nwere ike gbakọọ dị ka usoro: μ = F / S. Ọ bụ zuru ma ọ bụ ike viscosity. Units ịtụ na SI usoro, o nwere ike kwuru na dị ka ndị onwa abụọ.

The viscosity bụ ihe dị mkpa anụ ahụ-chemical e ji mara ọtụtụ bekee. Ya uru n'ime akaụntụ ke imewe na ime ihe nke piping na ngwaọrụ bụ nke ije (e.g., ma ọ bụrụ na ha na-eji maka pumping) mmiri mmiri ma ọ bụ gaseous ọkara. Ọ nwere ike na-abụ mmanụ a, gas na ha site-ngwaahịa, wụrụ awụ slag ma ọ bụ iko, na na. Viscosity na ọtụtụ mgbe bụ qualitative e ji mara nke intermediates na nke ikpeazụ ngwaahịa nke dị iche iche manufactures, ebe ọ na-adabere na Ọdịdị nke ahụ umi na-egosi na physico-chemical ala nke ihe onwunwe na mgbanwe na nkà na ụzụ. Ọtụtụ mgbe, na-eme atụmatụ na-eguzogide ka deformation na-adịghị eji ma ọ bụ ngafe nke ike na kinematic viscosity, nke nkeji SI nkeji na-owụt ke square mita kwa nke abụọ. Kinematic viscosity (denoted site ν) bụ ruru nke di omimi viscosity (μ) na ọmụmụ njupụta (ρ): v = μ / ρ.

Kinematic viscosity - a physico-chemical e ji mara nke ihe onwunwe, na-egosi ya ike na n'okpuru ihe nke ndọda agha iguzogide eruba.

The SI unit nke kinematic viscosity n'ihe a kọrọ dị ka m2 / s.

Na CGS usoro viscosity tụrụ na Stokes (St) ma ọ bụ centistokes (CST).

N'etiti ndị a ji atụ nkeji e ndị na-esonụ mmekọrịta: cm 1 = 10-4 m2 / s, mgbe ahụ, 1 CST = 10-2 cm = 10-6 m2 / s = 1 mm2 / s. Ọtụtụ mgbe kinematic viscosity bụ ọzọ na-abụghị systemic unit ịtụ - a Engler degrees, nke Stokes nyefe nwere ike rụrụ site ahụrụ anya usoro: v = 0,073oE - 0.063 / oE ma ọ bụ tebụl.

Iji tọghata ike viscosity nke usoro nkeji nwere ike ga-eji na extrasystematic akụkụ: 1 Pa • c = 10 poises. Shorthand e dere: AP

Abụkarị nkeji na-usoro ọmụmụ viscosity normative akwụkwọ na okokụre (azụmahịa) ngwaahịa ma ọ bụ usoro chọrọ on interm ọnụ na-anabata nso nke mgbanwe nke a qualitative àgwà, na-na njehie ịtụ.

Iji chọpụta viscosity n'okpuru laabu ma ọ bụ ulo oru ọnọdụ ndị viscometers dị iche iche na aghụghọ. Ha nwere ike ịbụ rotary, na bọl, capillary, ultrasonic. Ụkpụrụ nke odomo viscosity nke a iko capillary viscometer dabeere na-ekpebi ngafe oge nke mmiri mmiri site a calibrated capillary tube nke a ụfọdụ dayameta na ogologo, mgbe nile nke viscometer ga-atụle. Ebe ọ bụ na viscosity nke ihe onwunwe na-adabere na okpomọkụ (na-amụba, ọ na-ga ibelata n'ihi na molekụla kinetic ozizi dị ka a n'ihi nke osooso nke random ngagharị na na mmekọrịta nke ụmụ irighiri), nke mere na ule sample ga-aka iso ruo oge ụfọdụ na ụfọdụ okpomọkụ nkezi ikpeazụ ofụri olu nke sample. E nwere ọtụtụ ụzọ nke tozuru etozu viscosity ule, ma ndị kasị - bụ interstate ọkọlọtọ GOST 33-2000, nke na-kpebisiri ike dabere na kinematic viscosity, nke nkeji na nke a mm2 / s (CST), na ike viscosity na-recalculated dị ka ngwaahịa nke kinematic viscosity site njupụta.