Flow network modeling: a case study in expedient system prototyping

Fortunately for engineers responsible for thermal management of today's electronic systems, many tools exist that provide for efficient, comprehensive thermal design. These tools, including heat transfer correlations, Computational Fluid Dynamics (CFD) solvers, and Flow Network Modeling (FNM) techniques, assist engineers in answering complex layout questions and proposing thermally feasible design alternatives quickly. This paper presents the use of FNM as proposed by G. Ellison (1984), to perform a first order thermal analysis on a next-generation mid-range computer design. Ellison's method is used to predict system level pressure drops and air-mover performance in the complex computer system prior to building hardware, performing sub-system flow measurements or completing system level CFD analyses. In this application, the use of FNM allowed a small design team to sufficiently validate the system layout early in the product's design cycle, enabling continued sub-system layout, detailed design; and prototype production within the constraints of the project's aggressive schedule. Results of the Ellison based approach are compared with those of a commercially available FNM software package and with data taken from a system prototype. Comparison shows that the results agree well, validating the use of FNM as an aid in developing thermally feasible computer designs.