Modeling and evaluation of fluid cooling systems for Avionics

Abstract

Next generation aircraft will use more electronic devices for an increasing number of functions and tasks. These systems will carry out the same tasks that nowadays are executed by pneumatic or hydraulic devices. Furthermore, new functions such as communication an in-flight entertainment systems will require more electric power. These needs of required performance are usually in contrast with the necessity to reduce the weight and volume of the installed electronic devices. However, the increasing components integration inevitably leads to higher power densities at all levels of electronic packaging. In the light of this, the aeronautic industry has to manage the issue of dissipation of high heat fluxes of the installed avionics. Indeed, the right design of the proper cooling system for avionics has become a crucial point not only in terms of effect on the environmental control system, but also for the avionics performance and reliability. In the light of this, one of the main purposes of the TOICA project is to evaluate the effectiveness of traditional air cooling technology and the reliability of innovative cooling solutions. The present work proposes two different models of cooling architectures: the first one exploits the standardized air-cooling technology, base on the ARINC 600 specificatons; the second one adopt both the traditional air-solution and an innovative liquid one. The study focuses on the modeling of these two possible architectures, in order to provide an efficient sizing tool for a first dimensioning process and evaluation of weight and cost of the systems. The final result of this dissertation is a complete project-library AirLiq_CoolingLibrary in Modelica, which includes all the models and utilities that have been implemented to simulate the behavior of these architectures. Since this work represents the first modeling step, the hypothesis and assumption for each component are made in the light of the provided design requirements. The performed simulations illustrate that the architecture models respect the design requirements and the models are able to carry out reliable results in short time of simulation, which is a fundamental requirement for a sizing-tool.