Sense and nonsense of heat transfer correlations applied to electronics cooling

Generations of mechanical engineers have been educated to use the correlations that fill the textbooks Russell is mentioning because: "For convenience of engineering applications, correlation equations are developed over the entire range of dimensions and for any Pr-number". Unfortunately, for a thermal designer, real-life is more like hell than paradise, and hence it is high time to address the question: "How convenient are these correlations in real-life?" When it comes to thermal management of electronic systems, the answer is that correlations are not only completely useless but also dangerous because their use by nonexperts gives a false sense of safety. This paper tells why.