Weakly nonlinear waves in a linearly tapered elastic tube filled with a fluid

In the present work, treating the arteries as a tapered, thin-walled, long and circularly conical prestressed elastic tube and using the long-wave approximation, we have studied the propagation of weakly nonlinear waves in such a fluid-filled elastic tube by employing the reductive perturbation method. By considering the blood as an incompressible inviscid fluid the evolution equation is obtained as the Korteweg-de Vries equation with a variable coefficient. It is shown that this type of equations admits a solitary wave type of solution with variable wave speed. It is observed that the wave speed increases with the scaled time parameter tau for positive tapering while it decreases for negative tapering, as expected. (C) 2004 Elsevier Ltd. All rights reserved.