Abstract:The coolant flow in the aircraft liquid cooling system is usually regarded as an important parameter of the assessment of the system performance. With the aid of utilizing the diameter-variable ducts in the liquid cooling system as a throttling element, the coolant flow can be measured by using the differential pressure method. By applying data fitting to the experimental findings obtained from the groud calibration system, the characteristic curves of the coolant flow versus differential pressure for different temperature and pressure values were obtained. Furthermore, the formulate for the correction of calculated coolant flow were gained through linear interpolation. The flight test results indicate that the method is feasible for the measurement of the coolant flow of the aircraft liquid cooling system and, therefore, the problem of inconvenient refitting of flowmeter for the liquid cooling system has been solved.