Author:

Keywords:

Second Law, entropy, electronics cooling, engineering, system design

Abstract:

The Second Law of thermodynamics has inspired many scientists over the past century. Also in the field of engineering it has found applications like for example exergy and entropy generation minimization (EGM). This dissertation aims to assess these applications by questioning their usability in engineering design.The Second Law of thermodynamics is half a conservation law because entropy can be created but not destroyed. This is mathematically expressed by an inequality sign (dS ≥ 0). From a modelling point of view, this inequality sign is inconvenient. Therefore engineering science often uses the equality sign to set a benchmark on reality (exergy) or minimizes the gap between reality and the reversible benchmark (EGM).Unfortunately reversibility is infeasible. It is the inequality sign which describes reality on macro scale, not the equality sign used as a benchmark. This inherent discrepancy urged us to start a quest for the added value of the Second Law in engineering design. A quest which took us five years. This thesis presents our itinerary in Second Law based design of engineering applications.We start with a general acquaintance with the Second Law. Subsequentlywe offer three new perspectives on the Second Law as it is applied in engineering. These perspectives serve as a framework to assess current literature on applied Second Law based analysis and design. After pinpointingtrumps and pitfalls, we illustrate when and how the Second Law can bring an added value to engineering design. Finally we put the work itself in a broader context to offer conclusions that have the ambition to change the reader’s perception on the use of the Second Law in engineering.