In a solar oven, the three types of energy transfer while cooking soup are conduction, convection, and radiation.
Conduction: Conduction is the transfer of heat and energy through direct contact between objects. In a solar oven, conduction occurs when the soup bowl comes into contact with the oven surface. Solar ovens absorb and retain heat from the sunlight, typically using reflective materials and insulation. As the bowl touches the hot oven surface, heat is transferred from the oven to the bowl through conduction. This causes the soup to heat up.
Convection: Convection is the transfer of heat energy through the movement of a fluid, such as air or liquid. In a solar oven, convection occurs when the air inside the oven is heated by solar energy and circulates. As the air becomes warmer, it rises due to its lower density, creating a convection current. This circulation of hot air helps distribute heat evenly throughout the oven, including around the soup bowl. As a result, the soup heats up through convection.
Radiation: Radiation is the transfer of heat energy in the form of electromagnetic waves, such as infrared radiation. In a solar oven, radiation is the primary mode of energy transfer. The oven captures sunlight and converts it into heat energy. Sunlight consists of various wavelengths, including visible light and infrared radiation. When sunlight enters the solar oven, it is absorbed by the oven's materials, particularly by dark-colored or reflective surfaces. The absorbed sunlight is then re-emitted as infrared radiation, which is a form of heat energy. This infrared radiation heats the soup bowl and raises its temperature.
Overall, in a solar oven, conduction occurs when the bowl of soup comes into direct contact with the hot surface of the oven, convection happens through the circulation of hot air inside the oven, and radiation transfers heat energy from absorbed sunlight to the soup through infrared radiation. These three types of energy transfer work together to cook the soup in a solar oven.