A non-Newtonian fluid is one whose اللزوجة changes under an applied إجهاد القص. Unlike a Newtonian fluid where viscosity is constant, its flow properties are not described by a linear relationship between shear ضغط ([latex]\tau[/latex]) and shear rate ([latex]\dot{\gamma}[/latex]). This dependency can manifest as ترقق القص (تقل اللزوجة مع الإجهاد) أو سماكة القص (تزداد اللزوجة مع الإجهاد).





