Loop Heat Pipe Testing and Analytical Model Verification at the U.S. Naval Research Laboratory
Heat transfer characteristics of a Loop Heat Pipe (LHP) is difficult to predict due to the complex nature of thermal interaction between the LHP itself and the environment it operates in. The overall thermal conductance varies not only with the power input, sink temperature and ambient temperature as expected, but also with the system initial condition and/or previous history of its operation. Hence, the analytical modeling of LHPs often yielded inaccurate results when compared with the actual data. The U.S. Naval Research Laboratory (NRL) recently completed the development of a transient LHP model. Accordingly, NRL carried out an extensive LHP test program, in part, to provide test data for the model verification. In this paper, description of the test program and results of the model verification will be presented.
Capillary heat loop technology: Space applications and recent Canadian activities
Abstract Capillary heat loops (CHL) are heat transfer designs with high-effectiveness, high-performance, high-reliability, high-flexibility, and anti-gravitation features of interest to the space community. At the Canadian space agency a project has been initiated since 2002 to develop an understanding of CHL technology. The technology is targeted towards the thermal control systems of miniaturized satellites. This paper presents reviews of CHL modeling and space applications and introduces the recent development of loop heat pipe (LHP) technology in Canada in the hardware development, application, performance testing, analytical prediction and numerical modeling.
An Introduction to Property Theory: Utilitarian Property Theories
As a leading property law casebook puts it, “[u]tilitarian theory is, without doubt, the dominant view of property today, at least among lawyers.” This is certainly true, but the story is also significantly more complicated. Although utilitarian analysis provides tremendous insight into the institution of property, it raises a number of important questions when treated as a comprehensive theory of property. Moreover, the term utilitarian masks a great deal of intellectual and methodological diversity. Rather than a single utilitarian theory, it is more appropriate to speak of a number of utilitarian (or even utilitarian-influenced) property theories . For our purposes, these utilitarian-influenced theories include many contemporary theories that refer to themselves as economic or welfarist . In this chapter, we will explore the broad outlines of these theories, focusing on their points of overlap and also on key areas of disagreement. A BRIEF INTRODUCTION TO UTILITARIANISM Utilitarianism is a consequentialist moral philosophy, that is, one that judges the rightness and wrongness of actions or rules or institutions by the goodness and badness of the consequences they bring about. Utilitarianism assesses the goodness or badness of consequences in terms of their tendency to maximize utility or welfare. Bernard Williams has observed that “[t]he fathers of utilitarianism thought of it principally as a system of social and political decision,” as opposed to “a system of personal morality.” As Williams correctly notes, it is sometimes hard to keep these two domains apart. Nevertheless, it is plainly as a theory of social choice that utilitarianism has been deployed in the context of property theory.