Papers Published

  1. Bejan, A., Thermodynamic optimization of geometry in environmental control systems for aircraft, Heat and Technology, vol. 18 no. 2 (2000), pp. 3 - 10 .
    (last updated on 2007/04/06)

    Abstract:
    This review draws attention to an emerging body of work that relies on global thermodynamic optimization in the pursuit of flow system architecture. Exergy analysis establishes the theoretical performance limit. Thermodynamic optimization (or entropy generation minimization) brings the design as closely as permissible to the theoretical limit. The design is destined to remain imperfect because of constraints (finite sizes, times and costs). Improvements are registered by spreading the imperfection (e.g., flow resistances) through the system. Optimal spreading means spatial and temporal distribution, geometric form, rhythm, topology, and geography. System architecture springs out of constrained global optimization. The principle is illustrated by simple examples from the optimization of energy-system design for aircraft: The cruising speed for minimum exergy destruction, and the structure of heat exchangers for environmental control systems.

    Keywords:
    Thermodynamics;Control systems;Heat transfer;Entropy;Optimization;