A SIMILARITY-BASED APPROACH TO THE OPTIMI ZATION OF REGENERATIVE GAS CYCLES .2. PISTONS AND REGENERATORS

To optimize the design of regenerative-gas cycles, such as the Stirlin g or the Vuilleumier cycle, a hierarchical approach was suggested in p art 1 of this contribution, first selecting the fundamental parameters that refer to the whole cycle, e.g. the speed or the pressure, al the highest level. As the next step, the distribution of the temperature- related dead volume onto the various cycle components is optimized, le aving the determination of the optimum geometric parameters at constan t dead volume for each of these as the remaining suboptimization probl ems at the lowest level. Having solved this problem for tubular heat e xchangers already, this will be done for pistons and for regenerators in the following. Again, using some simplifying assumptions, an analyt ical solution can be found for the former, which can even be decoupled from the following optimization of the regenerators. For these, the s olution of the equation system fan only be found numerically, though a t minor effort. Having solved all these subproblems, an optimization o f the dead volume distribution can be performed based upon these, and ''the'' optimum geometrical cycle configuration can be determined for any choice of the above-mentioned fundamental parameters. So, finally, some general statements concerning the selection of these are possibl e.