Analysis of dynamic performance of crossflow heat exchangers for helicopters

Modeling and simulation of transient heat transfer in crossflow heat exchanger are necessary for developing the oil system in helicopters. The dynamic model of crossflow heat exchanger was established by using lumped thermal controlled methods, and its accuracy was proved by dynamic experimental results of crossflow heat exchanger. Through analysis of dynamic performance of the crossflow heat exchanger, especially considered the dynamic response of the outlet temperature in the hot side to the change of the inlet temperature in the same side or the cold side. Based on the analysis of dynamic transfer function, the most important influence coefficients are obtained, which are regenerative time constant of core and time constant of temperature changing in the hot side along with flow time. By reducing the values of two most important influence coefficients, the dynamic detention time could be reduced efficiently. The dynamic performance of heat exchanger and the whole system also could be improved efficiently.