THE PODMODELI PROGRAM - GAS-DYNAMICS

Initial ideas are presented and the characteristic features of the imp lementation of the ''POD-MODELI'' (''submodels'') program, which has b een written during recent years [1], are described. At the foundation of this program lies a deliberation concerning the exhaustion of all t he possibilities of an exact simplification of ''large'' mathematical models by means of the full use of the symmetry properties built into them. Such a simplification is achieved by changing to submodels which describe classes of exact particular solutions and lead to a reductio n in the dimensions of the problems making them easier to analyse. Alt hough, in its full scope, this program is obviously not exhaustible, n evertheless, as regards each fixed ''large model'' which arises in the mechanics of a continuous medium and, in general, in mathematical phy sics, it is specific and fully realizable in practice and serves for t he organization and supplementation of a databank on mathematical mode ls of natural processes.