Study of the effect of the shape of the intake valve with a different number of spiral guides (blades) when changing the pressure in the cylinder of a small-sized marine engine (SMD) Ch8.5/11.

Goal. In modern designs of small-size marine diesel engines (SMD), an urgent task is to find ways to obtain the highest quality mixture and improve parts in order to increase their efficiency, durability, and environmental friendliness. The object of study is a factory-made SMD valve and a valve with a modified design with the addition of spiral guides (blades, screens) and studying the effect on them of the loads exerted in the engine cylinder from turning the crankshaft (PKV) using the example of SMD Ch8,5/11. At the same time, the construction material remained homogeneous.

The methodology. To accomplish the tasks set in the work, the finite element method (FEM) was used, implemented in the Ansys program, where an unsteady thermomechanical calculation of valves of various designs with homogeneous material was performed using the example of the SMD Ch8,5-11 valve, where the temperature fields studied earlier were transferred to the pressure tested by the valve, followed by an analysis of the results obtained, their study and comparison.

Results. During the finite element research, the parameters of total deformations and operating stresses were calculated and visualized, the actual safety factor was calculated, and the value of the spiral guides available on the valves was analyzed. Since the calculation was non-stationary, the maximum stresses experienced on the valves during operation were selected for the study of the SMD.

Conclusions. Based on the data obtained, it can be established that the overall deformation practically does not change when the valve design is changed, while the operating voltage has increased significantly and reached its maximum on the valve with 6 blades. The obtained values and visualization of the program show that the actual safety margin of valves with blades is significantly reduced.