(Solved): Flow of a Non-Newtonian Fluid. Fluid flows through a cylindrical pipe of constant crosssection and ...
Flow of a Non-Newtonian Fluid. Fluid flows through a cylindrical pipe of constant crosssection and radius R, under steady state conditions. The stress tensor for the fluid obeys ?=?pI+2?e+4?e?e where I is a tensor whose components are given by Iij?=?ij?, where ?ij? is the Kronecker delta, and e=21?(?v+?vT) is the rate of strain tensor. The pressure gradient is constant along the axis of the pipe,
?z?p?=?K The parameters ?,?, and K are constant. This problem is analogous to the flow of a Newtonian fluid through a pipe, except that the fluid obeys the alternative expression for stress given above. There are no body force effects. a). Derive the velocity profile, vz?(r), for the flow. It may be helpful to recall that drdf?+rf?=r1?drd(rf)? where f is a function of r, i.e. f=f(r). In addition, the following information is given (???)r?=r1??r?(r?rr?)?+r1?????r????r?????+?z??rz??(???)??=r1?????????+?r??r???+r2?r???+?z???z??(???)z?=r1??r?(r?rz?)?+r1??????z??+?z??zz??? b). Derive the pressure distribution in the pipe to within an arbitrary constant. In doing this part, check dependence of the pressure on all coordinate directions, or write a good justification as to why the pressure should not depend on a particular coordinate variable. Show all work.