Kinematic viscosity thiab dynamic viscosity muaj feem xyuam, tab sis lawv muaj ob lub ntsiab lus sib txawv, tab sis nws yog ib qho yooj yim rau confuse lub ntsiab lus ntawm kinematic viscosity thiab dynamic viscosity.
Viscosity yog hais txog kev sib txhuam sab hauv ntawm cov kua, qhia txog qhov kev tiv thaiv ntawm cov molecules.
Kinematic viscosity yog qhov piv ntawm viscosity ntawm cov kua rau qhov ntom ntawm cov kua dej ntawm tib qhov kub. Nws yog ib qho kev ntsuas ntawm qhov ntws tsis kam ntawm cov kua hauv qab qhov kev ua ntawm lub ntiajteb txawj nqus, thiab chav tsev ntawm kinematic viscosity yog (m^2) / s. Kinematic viscosity ν=μ/ρ, μ yog lub zog viscosity ntawm cov kua, ρ yog qhov ceev ntawm cov kua.
Dynamic viscosity yog hais txog lub zog uas yuav tsum tau ua los tsim ib chav tsev ntws uas siv ib cheeb tsam ntawm cov kua txheej hauv ib chav tsev nyob deb. Hauv chav tsev, chav tsev ntawm kinematic viscosity yog pa.s. Cov mis rau kev xam cov dynamic viscosity ntawm cov kua: μ=τ/(du/dy), qhov twg τ yog qhov kev sib txhuam sab hauv ib chav tsev ntawm cov kua ntws, thiab du / dy yog qhov tshaj tawm gradient.
Kinematic viscosity thiab dynamic viscosity yog ob qho kev ntsuas rau kev ntsuas cov viscosity ntawm lubricating roj. Qhov me me dynamic viscosity, qhov zoo dua qhov kub tsis tshua muaj fluidity; ntawm qhov tsis sib xws, qhov phem tshaj qhov kub tsis tshua muaj fluidity ntawm cov roj lubricating. Qhov me me ntawm kinematic viscosity, lub lubricating roj viscosity qis dua, qhov ntau dua kinematic viscosity, lub lubricating roj viscosity siab dua.