### Thermal Management  
Aircraft thermal management is very important for reliable operation of the aircraft [12]. Problems related to aircraft thermal management of FCS not only affect the operational performance at high Mach number because of the surface friction heating [13] but also have impact on the modern aircraft at low Mach number due to the internal heat. Airborne avionics, hydraulic control system, lubricating oil system, aircraft environmental control system, and other systems produce a large amount of waste heat load which should be managed, as well [14]. Meanwhile, low thermal conductivity of the composite skin on new aircraft also leads to worse heat management [15]. Moreover, transient peak thermal load generated by the high energy weapon should be temporarily stored in the phase change energy storage materials and then be released to the fuel [16].  
Taking the fuel as heat sink to absorb waste heat energy from airplane mechanical-electronic system has the following advantages [17]: One is that the fuel can absorb the thermal load with the lowest heat-sink cost and the fuel to be preheated to a suitable temperature range before entering to combustor is helpful to the combustion. The other is that traditional air cycle system cannot meet the cooling exchange need of the airplane. Taking the fuel as heat sink can significantly improve the cooling capacity of aeroengine. However, the thermal management of FCS also confronts some issues to be addressed [18]. Firstly, the variation of fuel consumption and temperature always results in the dynamically change of the cooling capacity of the heat sink. Secondly, the maximum fuel temperature at the inlet of the combustor must be less than 135 \({}^{\circ}\)C to prevent fuel coking [19; 20]. To solve these problems, research on aircraft integrated thermal management system (TMS) is very necessary.  
One method of TMS is to increase the efficiency of FMU and to research and development more effective designs [21]. Variable displacement vane pump (VDVP) [22] used in pump-controlled flowrate control system and variable speed pump (VSP) [23] used in motor-based flowrate control system provide a promising approach to reduce the specific fuel consumption (SFC). VDVP is superior to the legacy system in the pollution resistance, fast response, and high thermal efficiency. VSP not only can reduce the thermal load of the conventional cooling accessories, such as fuel cooled ram air cooler (FCAC) and the absorptive capacity of the heat exchangers (HXs), such as hydraulic oil cooled fuel cooler (HCFC), oil cooled fuel cooler (OCFC), and PAO cooled fuel cooler (PAO-CFC) arranged between LP and HP, but also make contributions to the SFC and CO\({}_{2}\) reduction [24; 25]. That is to say, the variable pump system can not only improve the performances of the aeroengine but also be more environmentally friendly.  
The other approach of TMS is to actively dissipate thermal loads [25]. Through equipping heater exchangers and cooler exchanger in the aircraft, we can actively manage the thermal loads. The heater exchangers transfer thermal load to fuel in the feed line, and, meanwhile, to control the temperature of the fuel to flow into the high pressure pump (HP), part of the fuel returns to the fuel tank through return line with recirculation cooler.  
If the thermal load transferred to atmosphere is less than the thermal load of the fuel to be absorbed in the cooler, the fuel to enter into the tank will increase the temperature of the fuel in the tank, and the serious case will result in aircraft failure [26].  
This review article mainly deals with fuel flowrate control and fuel thermal management. We will mainly overview the present status of fuel flowrate control-, pump-, or motor control-based FMU, such as VSP and VDVP, the influence FMU on thermal management, the control strategy for thermal topology network, and the method to extend thermal endurance by controlling the flowrate of fuel and scheduling heat sinks in the aircraft.