CFD Assisted Control System Design for Chip Cooling

In this paper, a computational fluid dynamics (CFD) assisted control system design methodology has been described in detail. The entire design and evaluation procedure has been illustrated through a feedback control system synthesis for a CPU chip cooling system. The design methodology starts with a full-scale CFD simulation of the nonlinear dynamic process to generate the input and output databases of the process. Using this data set, linear dynamic models around specified operating points are obtained using system identification techniques. Based on these models, one can design appropriate control systems to meet the required closed-loop control system specifications. To illustrate the effectiveness of this technique, it has been used to design a controller for a PC chip cooling system. In particular, the coupling issues between ‘real-time’ dynamic controllers with non real-time CFD simulation have been resolved. A physical experimental test bench based on a cooling system of a Pentium III CPU has been constructed. The feedback linear control systems designed by the proposed CFD approach have been evaluated experimentally for six CPU load conditions.