Boundary layer Blockage, Venturi Effect and Cavitation Causing Aerodynamic Choking and Shock Waves in Human Artery Leading to Hemorrhage and Massive Heart Attack - A New Perspective

摘要

A powerful closed-form analytical model is discovered for estimating the 3D boundary-layer blockage for solving the real world adiabatic and diabatic fluid problems in physical, biological and health sciences, which our scientific communities have been waiting for getting a solution for more than a century. The exact solution obtained from this model at the Sanal flow choking condition (V. R. Sanal Kumar et al.[1], AIP Advances, 8, 025315, 2018) can be taken as a credible benchmark data for the verification, calibration and validation of various viscous flow solvers as well as the flow meters. We discovered that there are possibilities of Venturi effect in the partially blocked arteries (due to boundary layer blockage and/or plaque) creating cavitation and shock waves followed by pressure overshoot leading to hemorrhage and massive heart attack due to the catastrophic rupture of the artery with high relaxation modulus as a result of the memory effect (stroke history) carried by the arteries with thermoviscoelastic material properties. We observed that there are likelihood of the aerodynamic flow-choking in the blockage region of any internal flow system including the human artery when the differential pressure (?P) is equal to the product of the differential density (?p) and the square of the axial velocity (V_(axial)) at the blockage region (?P = V_(axial)~2 ?p)· Attaining this significant physical condition in any internal flow system is very dangerous owing to the fact that it invites shock waves if the downstream port cross-sectional area of the duct is higher than the blockage region where the aerodynamic choking occurs. Note that a different type of limiting condition arises when the Venturi effect acting on the blood flow through the restriction (micro CD nozzle throat effect) causes a decrease of the blood pressure beyond the restriction to below that of the vapor pressure of the human blood at the prevailing blood temperature. At that point, the artery blood will partially evaporate into bubbles of vapor and the subsequent collapse of the bubbles causes cavitation. The aerodynamic flow choking may occur, as a result of cavitation, when the normal relationship between flow and increased pressure drop is broken. Note that cavitation is quite noisy and can be sufficiently violent to physically damage valves, arteries and blood vessels. At the choked flow condition, the systolic-to-diastolic blood pressure ratio (P_(systolic)/P_(diastolic)) is a unique function of the heat capacity ratio of biofluid, which inherently exhibits compressible fluid properties. We proved conclusively through state-of-the-art in silico studies that the sudden hemorrhage and massive heart attack can occur due to the boundary-layer blockage of diabatic biofluid while attaining the aerodynamic flow-choking condition; and evidently without any iota of symptom of plaque formation (aneurism/collusion) in arteries of human being and animals. This seminal research work, above the level of any winning Nobel Prize work, disclosing the fundamental cause of hemorrhage and heart attack is a pointer towards for an in vitro and/or in vivo validation across the globe for finding solutions for creating an unchoked biofluid conditions in the artery of human being and animals case by case or otherwise through clinical trials for prohibiting the hemorrhage and massive heart attack due to the formation of shock waves as a result of aerodynamic flow-choking.