Thermal Managment Flashcards
What type of thermal management will we consider in this course
Steady state thermal management e.g. heat sinks
What is the primary method of heat transfer for solids
Conduction
What is convection
Heat transfer between a solid and a moving fluid
What is Radiation
Transfer of electromagnetic radiation
What is the main type of heat transfer for heat sinks
Convection
What are the 2 types of convection
Natural and Forced
What is natural convention to remove more energy
Natural convention current cause the hot air to rise and be carried away
What is forced convention
A fan blows cold air over the heat sink surface
What type of flow is best for the fan in forced convection
Turbulent
What is there reason for heat sinks shape
To maximise surface area for heat to be removed
What is the ability of a heat sink to dissipate energy specified by
Thermal resistance
What is the unit for thermal resistance
Degrees C per Watt
What is the symbol for thermal resistance
Theta (with to subscripts e.g JA)
What does a black coating of heat sink do
Improves the radiation characteristics and reduces thermal resistance by 15%
How does maximising surface area effect thermal resistance
It decreases it