Abstract: The C hebyshev collocat ion met hod and Fast Fourier Transform ( FFT)is employed for computing the temperature,pressure, and velocity fields in a flat thin center-fed disk-cavity for the flow of thermoplastic materials. The cavity-filling process is treatedas a transient and non-isothermal flow of a non-Newtonian flnid with moving bonndary Inthe nnmerical scheme the spatial discretization is spectral but the temporal discretizationuses covent ional Crank-Nicolson finite-difference,Goo d agreement is obtain...