Dascalescu, S. and Receanu, M., "Air Flow Control Servomechanism for Cooling the Radiator of a Car Engine," SAE Technical Paper 2013-01-1296, 2013, doi:10.4271/2013-01-1296.
The servomechanism for air flow control has as effect on cooling starting by the shorting of warming up engine period with the useful consequences: fuel consumption, wear and pollution decreasing. A method for cooling air flow control is the use of a program-controlled blind who obturates section of the radiator of car engine, especially for reduced ambient temperature (≺+50C). For experiments it is used an electronic engineering installation who contains: two thermo resistances for the coolant temperature at the inlet, respectively at the outlet to the radiator, a flow meter with Hall sensor for measuring the coolant flow in the radiator loop, a Precision Analog Microcontroller and Laptop. We denote the first transient phase when the valves of thermostat become to open and the second transient phase between the extreme positions: valve is fully closed or fully open. The experimental data demonstrate the reduction of second transient phase and a fuel economy in the case of obturated radiator with different positions of the blinds for reduced ambient temperature. The software for data acquisition is executed in C++ or LabVIEW for processing the signals. A mathematical model with strongly nonlinear system of the considered car engine cooling system with conventional thermostat, radiator, engine and heater is simulated in MATLAB/Simulink for an optimal control of the engine. The dynamic model includes hysteresis, since the way the thermostat opens when the temperature rises differs from the way it closes when the temperature decreases and delays introduced in the cooling loop system.