CFD Analysis of Flue Gases over Valve Spindle with Rotor Wings in 2 Stroke Marine Diesel Engines

Earlier in ships, the exhaust valves in 2 stroke diesel engines were actuated by a mechanism, controlled by rocker arms and camshaft. But due to weight and space constraints of the diesel engines of ships, the camshaft and huge rocker arms have been replaced by hydraulic power pack to actuate the valve. As a design modification, rotor wings were also attached to the exhaust valve spindles. When the exhaust valve opens, the exhaust gas rotates the wings and turns the spindle by a certain degree. In this paper, a study about how these rotors extend the lifeline of the spindles has been carried out. The paper outlines the various analyses conducted on the existent spindle design, the boundary conditions input to the software and the various results, namely temperature and pressure variation graphs, and moment reaction acting on the spindle. It also compiles an analysis of how the rotor wings have been modified to attempt to extend the lifeline of the spindles through computational fluid dynamics (CFD) and a comparison of the test results for various designs has been included.