Exam Question

### (a) Cause and Effect of Thermal Stressing in Cylinder Components
**1. Definition and Cause:**
Thermal stress is an internal stress induced in a body when it is subjected to a temperature gradient, causing different parts of the body to expand or contract by different amounts. In a marine diesel engine's combustion chamber components (cylinder head, liner, piston), this is caused by:
* **High Temperature Gradient:** The inner surfaces are exposed to intense, cyclic heat from combustion (1200-1800°C), while the outer surfaces are actively cooled by LT Central Cooling Water (around 80-90°C) or lubricating oil.