UNIFORM CHANNEL MICRO HEAT-EXCHANGERS

The performance characteristics of micro heat exchangers consisting of straight channels fabricated in a silicon wafer and operating with li quid nitrogen are evaluated theoretically. The three-dimensional conju gate temperature and flow fields are calculated numerically. The therm al resistance is computed as a function of various geometric parameter s. The optimal dimensions which minimize the heat exchanger's thermal resistance are identified. Additionally, a simple, approximate, analyt ical model, adequate when the ratio of the solid and liquid thermal co nductivities is large, is presented and used to predict the heat excha nger's optimal dimensions. The approximate model's predictions are com pared with the numerical results.