[mohsenz_136]

hello I want to simulate accelerating motion of the airfoil by using dynamic mesh.airfoil accelerates linearly after static position. I've divided domain into three interior. interior 1 is boundary layer mesh near airfoil edge . interior 2 is un structure mesh and interior 3 is structure in far field . i want to fix interior 1 and 3. i used macro define C-G-MOTION i have some question
1- how can i move wall with interior 1 without interior 1 and 3 deformation

[cfd seeker]

The zones which don't get deform in dynamic mesh are defined as "Static" while the zone which gets deform is defined as "Deforming"

[cfd seeker]

airfoil accelerates linearly after static position

By this you mean Mach no is changing with time?

[mohsenz_136]

acceleration of airfoil is 10 g and mach increase from o up 1.5 and initial of velocity is zero. boundary layer move with airfoil and it's mesh does not deform

[cfd seeker]

acceleration of airfoil is 10 g and mach increase from o up 1.5 and initial of velocity is zero

Linear acceleration is 10 g? If airfoil is just linearly accelerating then I wonder what type of UDF/macro you have used to define its motion because in normal case when airfoil is static and air is flowing through the domain built around it is just like an airfoil moving through the static air. So I guess you have write UDF to continuously change the Mach No during iterations process isn't it?