NUMERICAL-ANALYSES OF 2-DIMENSIONAL AND 3-DIMENSIONAL THERMOACOUSTIC CONVECTION GENERATED BY A TRANSIENT STEP IN THE TEMPERATURE OF ONE WALL

General two- and three-dimensional models were derived and solved numerically for the thermoacoustical convection that is generated in a compressible fluid by rapid heating of one of the vertical enclosing walls. Various temperature profiles were imposed impulsively on the heated wall of a two-dimensional enclosure and found to be reflected in the immediately ensuing velocity vectors in the fluid. After sufficient time, say, 0.2 s for helium at atmospheric conditions with an imposed temperature difference of 273 K, the velocity field was also influenced by buoyant forces. Stable numerical solutions were developed for the initial and reflected three-dimensional field of velocity in a cubic enclosure.© 1990 by Hemisphere Publishing Corporation.