Numerical scheme for modelling oxygen transfer in tubular oxygenators

The diffusion equation for oxygen transfer in tubular membrane oxygenators has been solved numerically by using the Crank-Nicolson method. The iterative procedure takes care of the nonlinear nature of the equations used in the model. The usual hypotheses have been used for the establishment of the nonlinear partial differential equation. Velocity profile (Newtonian, Cassonian fluid) and membrane resistance have been taken into account. Theoretical results have been compared with those obtained by the advanced front theory. Experimental results with several types of device are presented using either blood or saline. Boundary conditions are analysed. Comparisons between theory and results of experiments are presented.