Final answer:
Heat transferred from the combustion chamber to cylinder walls and fins is measured using calorimeters, particularly the Atwater bomb calorimeter in chemical reactions or pyrometers in temperature measurements. This process involves heat transfer and the measurement of temperature changes to calculate the heat transfer.
Step-by-step explanation:
Heat from the combustion chamber in an engine is transferred to the cylinder walls and then to the fins through a process called heat transfer. In the context of engines, heat is usually measured using devices like calorimeters. These devices measure the heat transferred to or from a substance, which in the case of an engine can be the metal itself. The measurement of heat transfer using this approach requires the definition of a system (the metals undergoing the heat transfer) and its surroundings (including the air around the fins).
One widely used calorimeter is the 'Atwater bomb calorimeter', which allows for very precise measurements of heat transfer through a chemical reaction. This apparatus involves igniting a sample in a bomb with an oxygen-rich environment and measuring the resultant temperature rise in the surrounding water.
Similarly, when considering engine efficiency and heat transfer, the fuel's combustion generates heat that is measured through changes in gas pressure and temperature. This heat is what ultimately does work by moving pistons in the cylinder.
An example of temperature measurement, which can be related to heat transfer, is the use of a pyrometer to check temperatures in applications like an aircraft carrier's ventilation system, as depicted in Figure 13.5. This is another method of assessing how well heat is being transferred or contained within a system.