Exam Question

(a)
(b) Piston of a large two-stroke crosshead engine, indicating the coolant flow:
(c) Causes of Piston Cracking and Burning in Large Two-Stroke Marine Engines and Their Avoidance:
Repeated cycles of heating and cooling during operation induce thermal stresses. These stresses, coupled with inertia forces (from reciprocating motion) and gas pressures during combustion, lead to fatigue cracking, particularly in areas experiencing high temperature gradients. This can be mitigated through optimized piston design (e.g., improved material selection with better thermal conductivity and reduced stress concentration points), ensuring consistent and effective cooling, and careful control of combustion parameters.