Researchers at TSC SB RAS have determined the optimal operational parameters for a cycloidal rotary engine

Scientists at Tomsk Scientific Center SB RAS, in cooperation with colleagues from Beijing University of Technology, have calculated the optimal operating parameters for a cycloidal rotary engine. Using advanced numerical techniques, they pinpointed the most effective engine operation mode, maximizing efficiency with minimum of fuel consumption. These findings were published in the Energy journal .

“The operation of modern engines, which are crucial components in electric and hybrid vehicles with extended range, is based on the Atkinson thermodynamic cycle, – explained Sergey Zambalov, senior researcher at the Physical Activation Laboratory of the Tomsk Scientific Center of SB RAS. – In a conventional four-stroke Otto cycle engine, the phases of compression and expansion strokes are equal. The whole premise of the Atkinson cycle is stroke disparity: the expansion stroke is longer than the compression stroke. The disparity or over-expansion allows the delivery of more energy from gases during expansion stroke and, therefore, increases the thermal efficiency of the engine”.

Using numerical simulation, scientists studied the characteristics of all strokes of the cycloidal rotary engine. They also investigated the vortex structures of turbulent flows within the engine that affect its performance, as well as how combustion waves form and propagate within the combustion chamber, yielding critical qualitative and quantitative insights into engine operation.

According to Sergey Zambalov, an important result was identifying the optimal range of over-expansion ratio coefficients, from 1 to 1.15 (the ratio of disparity between expansion and intake strokes). Within this range, the efficiency of the cycloidal rotary engine increases to 32.7-34.5 %. Furthermore, this mode of operation allows for reduced fuel consumption and emissions.

Given the absence of similar research endeavors in Russia, these findings carry profound theoretical and practical implications for cutting-edge enterprises in the automotive industry adopting cycloidal rotary engines.