Serial solution of heat-exchanger equations without a hybrid computer

A version of the serial-solution method is proposed which enables the equations of a counterflow heat exchanger to be solved without iteration, and with essentially central difference accuracy. The method is sufficiently simple for it to be implemented using an analogue circuit in conjunction with an inexpensive purpose-built hardware system. This hardware system performs some functions normally associated with a hybrid computer, and is described briefly. Specimen results are presented.