An application of computational fluid mechanics to the air flow in an infant incubator.

An application of the computational fluid mechanical method to the air flow in a two-dimensional model of an infant incubator was described. The air flow in a numerical model was simulated and the Navier-Stokes equations were directly solved using a finite-volume method incorporating a body-fitted coordinate system on a mini-supercomputer. The model was based on a real infant incubator, slightly simplified for the sake of computing speed, and included a model of a baby. The number of computation grids was 101 x 61 = 6161. The calculation was carried out under the condition of unsteady, starting airflow and the results were examined by the means of color graphics animation. There were several very large scale eddies in the incubator free space, and their global structure did not show strong changes once they were established. Although the global structure did not change, small scale eddies were shown to be produced around the air inlet and convected down through the free space of the incubator. From these results, we believe that assuming steady and uniform flow in the incubator may not always be relevant when considering heat loss of a baby in an incubator. The steady and uniform flow has been previously assumed either implicitly or explicitly by most of the authors.