ON THE VARIETY OF NOTATIONS OF THE ENERGY-CONSERVATION PRINCIPLE FOR SINGLE-PHASE FLOW

This review article recalls the achievements of the classic thermodyna mics for describing the thermodynamic behavior of flows. The numerical results obtained when trying to solve the basic system of partial dif ferential equations by means of modern computers have always to be cri tically examined. As is demonstrated for pressure wave analysis, lower order numerical methods predict with acceptable accuracy only the fir st few cycles. Then the solution degrades destroyed by numerical diffu sion. The inability of the lower order numerical methods to solve flui d mechanics equations for initial and boundary conditions defining str ong gradients is not an evidence that the equations are wrong. High ac curacy solution methods are necessary to satisfy future needs of the i ndustry.