MOLECULAR-DYNAMICS OF POLYMER-CHAIN IN A PULSATING FLOW WITH PURE TENSION

Numerical simulation of the dynamic behavior of 101-beads polymer chai n in with a hydrodynamic flow pure tension was performed by methods of collisional dynamics. The flow rate was periodically varied from zero to a value exceeding the critical value, at which the polymer chain u ndergoes phase transition from coil to unfolded conformation under sta tionary conditions. For a slowly changing flow rate (epsilon overdot), the polymer chain ''follows'' the variation of epsilon overdot (t): t he chain undergoes transition from coil to unfolded conformation durin g one flow pulsation and then collapses back. At high frequency of pul sations, when their period is comparable with the characteristic relax ation time, two metastable states of the chain, folded and unfolded, a re observed.