Another Approach to the Extended Stokes’ Problems for the Oldroyd-B Fluid

Figure 3

The contour path for the case 𝜆>𝜆_𝑟>0 with the conditions 0<𝜔<𝜔₁ or 𝜔>𝜔₂. Single pole 𝑠=0 is for the first problem and two poles 𝑠=𝑖Ω and 𝑠=−𝑖Ω are for the second problem.