Non-steady Processes Research Articles

The presentation of the nonsteady temperature field of a steam turbine rotor in generalized functions

Results of investigation into the possibility of expressing the temperature field of a turbine rotor in terms of generalized functions of temperature for use in the analysis of nonsteady thermal processes are presented.

Nonsteady Response of Plasmas to Microwave Radiation

A theoretical study of some nonsteady aspects of microwave radiation on ionized gases is presented. For weakly ionized gases, the concept of ``stabilized'' electron temperature is introduced. It is shown that under certain conditions, ionizations due to microwave radiation may be assumed to take place with the electron temperature remaining at this stabilized value. A simple expression for the ionization rate can then be obtained. Several time scales pertinent to these nonsteady processes have been obtained, and their relative order of magnitude is seen to be crucial in determining the nature of the nonsteady response. One type of nonsteady solutions for the ionization front of the gas under microwave radiation has been considered in some detail. Three different modes of response are possible depending on the initial electron density distributions. In particular, when the initial distribution is of the form ba exp (aξ)/[1 + b exp (aξ)], for ξ ≤ 0, where a and b are constants, the ionization front will propagate in the negative ξ direction toward the source of microwave radiation at a constant speed and with the same profile of electron density. This nonsteady response characteristic has some similarity with those observed in shock tube experiments.