Journal of Mechanical Engineering and Transport

An analysis of studies on the possibility of reducing fuel consumption of cars by replacing their power plants with two internal combustion engines installed in series is carried out. It has been determined that it is possible to reduce fuel consumption by reducing the unevenness of torque at the transmission input shaft, which in turn depends on the relative angular orientation of the crankshafts of the installed internal combustion engines. The study has determined that when installing two consecutive internal combustion engines, each of which generates an indicator torque that obeys the harmonic law, it makes it possible to shift the curves of the indicator torque and the crankshaft angle so that both engines operate in opposite phases. It is proposed to use a method of increasing the energy efficiency of cars by using two consecutive internal combustion engines, the crankshafts of which are installed relative to their initial angular position with the difference in the angular coordinates (angles of rotation) of the crankshafts of both engines relative to the initial position, which allows to reduce unproductive energy losses. Approximating the actual curves of change of the indicator torque by the harmonic law, taking into account the angle of rotation of the crankshaft, graphs of dependence of the indicator torque on the angle of rotation of the crankshaft of four-stroke internal combustion engines with different numbers of cylinders are constructed. It has been determined that with an increase in the number of cylinders of an internal combustion engine and the coefficient of the share of torque on the drive wheels, there is a decrease in the coefficient of unproductive energy consumption, which takes into account the influence of the unevenness of the indicator torque. The problem of ensuring the operation of the second engine in the counterphase of the first engine is solved, which should be fulfilled by the ratio of the angles of rotation of the crankshafts of the first and second engines relative to the initial (zero) position with the difference in the angular coordinates (angles of rotation) of the crankshafts of both engines relative to the initial position. The results of calculating the angle of the crankshafts' relative position when two internal combustion engines are installed sequentially in the opposite phase indicate a decrease in this angle with an increase in the number of cylinders

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