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--- doc:user:elements:volumes:fluid_iso_hypo_materials [2016/04/01 16:21] – carretta
+++ doc:user:elements:volumes:fluid_iso_hypo_materials [2017/12/01 12:11] (current) – [NortonHoffHypoMaterial] boemer
@@ Line 24: / Line 24: @@
 <note warning>
-Convergence when using this law may be difficult to achieve since there is no stiffness when shearing the material. If you encounter this kind of isssue, you may used **NortonHoffHypoMaterial** discussed below with a low viscosity parameter and NORTON_M = 1 to model a Newtonian fluid.
+Convergence when using this law may be difficult to achieve since there is no stiffness when shearing the material. If you encounter this kind of issue, you may use **NortonHoffHypoMaterial** discussed below with a low viscosity parameter and NORTON_M = 1 to model a Newtonian fluid.
 </note>
@@ Line 75: / Line 75: @@
 <note warning>
-To model Newtonian fluid with low viscosity (0.3 Pa.s for instance) it is important to used SRI elements instead of SRIPR. Indeed, SRIPR elements might induce oscillations in pressure and velocity fields. This seems to come from the different pressure value that can be stored at the deviatoric gauss points of SRIPR elements. For SRI elements, the hydrostatic pressure value is computed and stored at centre of each element. In that case, the pressure value on each element is unique.
+To model Newtonian fluid with low viscosity (0.3 Pa.s for instance) it is important to use SRI elements instead of SRIPR. Indeed, SRIPR elements might induce oscillations in pressure and velocity fields. This seems to come from the different pressure values that can be stored at the deviatoric Gauss points of SRIPR elements. For SRI elements, the hydrostatic pressure value is computed and stored at centre of each element. In that case, the pressure value on each element is unique.
 </note>
@@ Line 83: / Line 83: @@
 <note warning>
-A good compromise must be reached between the elements size and the time step value. If elements are too small, low viscous fluid elements may reach configurations where Negative Jacobian take place during Newton-Raphson procedure. The more elements you have for low viscous fluid, the more difficult is the convergence and therefore the time step is decreased automatically by Metafor. It is therefore better to avoid refining mesh elements too much where it is not needed.
+A good compromise must be reached between the elements size and the time step value. If elements are too small, low viscous fluid elements may reach configurations where the Jacobian of some element can become negative during the Newton-Raphson procedure. The more elements you have for low viscous fluid, the more difficult is the convergence and therefore the time step is decreased automatically by Metafor. It is therefore better to avoid refining mesh elements too much where it is not needed.
 </note>