Uncertainty analysis, which is frequently used in conjunction with experimentation, is adapted to the analysis of cross-flow heat exchanger performance predictions (rating, pressure drops, and fluid stream exit temperatures). The basic tools of uncertainty analysis are reviewed, and uncertainty analysis for cross-flow heat exchanger performance predictions is developed and illustrated with a detailed example. The use of uncertainty analysis in cross-flow heat exchanger performance predictions permits error bounds to be placed on predicted performance parameters and gives insight into the fidelity of such predictions. Moreover, uncertainty analysis gives considerable insight into the important physical variables and provides a reliable alternative to ad-hoc overspecification of fouling factors. Uncertainty analysis is shown to be a viable paradigm for cross-flow heat exchanger analysis.

The application of uncertainty analysis to cross-flow heat exchanger performance predictions

\n Precooled engine is a highly expected solution to achieve supersonic transport. As the crucial component, heat exchangers protect other components from ultrahigh temperature. In traditional design methods, the nominal result is multiplied by a safety factor, whose selection entirely depends on experience, ensuring sufficient working margin to cope with fluctuation of parameters. For aero-engine, heat exchangers must work reliably with minimum weight. An advanced method of thermal optimization design with parameters’ fluctuation is proposed and proved to be effective by experimental verification. The heat transfer area can be quantitatively linked with the design confidence level, considering the coupling effect of various parameters’ fluctuation. The probability density distribution of heat transfer area has the characteristic of positive skewness distribution. With the increase of design confidence, the required heat transfer area is growing faster and faster. After optimization, the design of heat exchanger meets the requirements and the weight is effectively controlled.

Thermal Optimization Design of Heat Exchanger in Supersonic Engine with Parameters’ Fluctuation

Optimization of exchanger design

A computer program is developed to predict the performance of heat exchanger systems with or without feedback. The program is used to analyze the effect of uncertainties on the performance of a feed-effluent heat exchanger system. By analyzing the sensitivity of the outcome variables to the uncertainties in the inputs, the most critical component of the system is identified. Applicability of the effective measures to limit the uncertainties and thereby improve the performance of the system is also discussed.

A. K. M. Mahbub Uddin

Papers

Effect of Uncertainties on the Performance of a Feed-Effluent Heat Exchanger System