Introduction The thermal resistance of a heat sink is a convenient way of describing its performance but, unlike its electrical counterpart, the thermal resistance of a heat sink is not a constant: it changes significantly with air flow. How we "understand" heat sinks is revealed by the models we use to describe their thermal resistance. Most thermal engineers use a single-term … [Read more...]

## The Benefits Of Using Hadiabatic In Thinking About Electronics Cooling

The heat transfer coefficient is used to describe convective heat transfer between a solid and a fluid, as in Equation (1). The heat transfer coefficient is a defined parameter, not a physical property like thermal conductivity, and different definitions are used for different situations. The preferred definition for use in the electronics-cooling situation is … [Read more...]

## Uncertainty analysis

Uncertainty analysis is the process of estimating the uncertainty in a result calculated from measurements with known uncertainties. Uncertainty analysis uses the equations by which the result was calculated to estimate the effects of measurement uncertainties on the value of the result. Uncertainty analysis is used in the planning stages of an experiment to judge the … [Read more...]

## Notes on Using Thermocouples

Introduction Thermocouples are the most widely used temperature sensor in test anddevelopment work. Accurate temperature measurements can be made at low costwith shop-built probes and ordinary low-level voltmeters. What Are Thermocouples and How Do They Work? Any two wires of different materials can be used as a thermocouple ifconnected together as in Figure 1. The AB … [Read more...]

## Evaluation of different heat transfer coefficient definitions

The analysis of convective heat transfer problems pivots on the accurate knowledge of the heat transfer coefficient, h. The heat transfer coefficient is affected by many parameters which have been defined differently by various investigators. for natural convection cases, the temperature distribution is the governing parameter, while for forced convection problems, the fluid … [Read more...]