Link:http://output.to/sideway/default.asp?qno=100200003 Fluid Motions Fluid MotionThe fluidity property of fluid makes the motion of fluid very
complex. The velocity variation of each fluid
particle during fluid flow within the velocity field
Linear TranslationThe linear translation of a fluid element in a small time interval with same field velocity along the flow direction, for example in xy plane ![]() Linear DeformationThe linear deformation of a fluid element in a small time interval with field velocity gradient along the flow direction, for example in xy plane ![]() Linear Strain RateThe linear strain rate or the rate of change of length per unit length along one of the flow direction can be expressed as ![]()
Let
![]() Angular RotationWhen there is a cross flow velocity gradient along the flow, the fluid element will rotate, for example in the xy-plane, ![]() Angular DeformationIn a small time interval, the angular deformations of the fluid element, for example in the xy-plane. ![]() Therefore for small angles, ![]() and ![]() Angular Strain RateThe angular strain rate or the rate of shear strain by definition can be expressed as ![]() and in terms of strain rate tensor ![]() |
Sideway BICK Blog 10/02 |