1997-06-18

Thermal Optimization of the ECS on an Advanced Aircraft with an Emphasis on System Efficiency and Design Methodology 971241

ABSTRACT

Two methods for analyzing and evaluating the environmental control system on an advanced aircraft as described in this paper include the conventional first law energy conservation technique and the second law entropy generation minimization technique. Simplified analytical models of the ECS are developed for each method and compared to determine the validity of using the latter to facilitate the design process in optimizing the overall system for a minimum gross takeoff weight (GTW). Preliminary results have illustrated the importance of taking into account system optimization based on system (or component) efficiency. For instance, even though different values were obtained for the rate of entropy generation, the second law analysis of a shell-in-tube heat exchanger led to an optimum tube diameter of 0.12 in (3.05 mm) when both R-12 and R-114 were used as the refrigerant in the vapor cycle. However, further research is necessary to determine whether this second law approach is advantageous for the integrated systems design engineer.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X