Stability of thixotropic uids in pipe ow

Linear stability of a thixotropic uid obeying the Moore model is investigated in pipe ow using a temporal stability analysis in which innitesimally small perturbations, represented by normal modes, are superimposed on the base ow and their evolution in time is monitored in order to detect the onset of instability. An eigenvalue problem is obtained, which is solved numerically using the pseudo-spectral Chebyshev-based collocation method. The neutral instability curve is plotted as a function of the thixotropy number of the Moore model. Based on the results obtained in this work, it is concluded that the thixotropic behavior of the Moore uid has a destabilizing eect on pipe ow.