Study On Characteristic Of Nonlinear Waves In Artery Blood Vessel Of Human

In recent years, the incidence of angiocardiopathy is on the increase and is badly endangering the health of human, which has been specified one of the three most common worldwide diseases by World Health Organization(WHO). So, it is significant for us to study the hemodynamics in order to obtain an ideal method which will be used to diagnosing the inchoate angiocardiopathy.It is well known that there are many nonlinear phenomena in life system. similarly, nonlinear characters exist in blood circulatory system. The development of hemodynamics, obviously, depends on the development of the nonlinear theory deeply. In this paper, the basal definitions of hemodynamics and the status quo of discovery on nonlinear sciences in this field have been introduced firstly.The disturbances transmit with the forms of stress waves in large arteries have been proved in second chapter of this paper. Some equations governing velocity v, pressure p and stressε_? have been obtained with the assumptions of a long, straight, circular, inhomogeneous thin walled elastic tube filled with an incompressible and viscous blood flow. Finally, stress waves are described by KdV equation, and theoretical results of velocity of stress waves are estimated and compared with experimental ones.In the third chapter of this paper, neutral disturbances that have a universal foreground in clinic application have been studied. A significative mend to Poiseuille flow has been shown, and the weak viscosity of blood condition have been assumed firstly. A vorticity equation of stream function and a KdV equation which described neutral disturbances have been obtained by the reductive perturbation method, respectively. The conclusions offer a theoretical base for diagnosing the inchoate angiocardiopathy.It has been studied that waves propagating in blood vessel is changing gradually, and finally grow into shock waves. A normal Burgers equation that describes pressure of blood has been obtained, which prove the shock waves are presenting . In the last chapter of this paper, the effect of the blood viscosity on blood stream and the velocity of the waves have been discussed. It is shown that the length of the blood vessel which forms the shock waves is larger than the actual length of blood vessel because of the dispersive effect of the viscosity. So, there are no shock waves in normal physiology fettle of human.