| Popis: |
I t is shown that, contrary to widely accepted opinions: (a) The addition of heat to a subsonic flow in a pipe modifies the flow conditions both downstream and upstream of the region of heat addition. (b) The Mach Number of the heated flow does not necessarily increase, approaching the sonic state, when heat is added; instead, it will increase or decrease, depending on the boundary conditions. (c) The static temperature of the gas does not decrease when heat is added within the range of initial Mach Numbers from ' v T to 1.0; instead, it increases continuously. (d) The attainment of sonic velocity in the heated region does not limit the amount of heat that can be added. (e) The mass flow may decrease as a result of the addition of heat but this decrease is in no way related to the attainment of sonic velocity in the heated region. A quantitative treatment of the problem is presented for the cases of greatest practical interest, and numerical examples are given to illustrate the procedures and conclusions. |
