Introduction Readers of ElectronicsCooling know about the rapid pace of technological developments towards an increasingly higher level of miniaturization and, hence, an incredible increase of dissipation power densities. Thus, restating some very well known facts (such as, we have already attained a level of power density that is comparable to nuclear power stations) would not … [Read more...]
Estimating Natural Convection Heat Transfer for Arrays of Vertical Parallel Flat Plates
A simple formula to estimate the natural convection heat transfer coefficient on a flat plate was presented in a preceding column [1]. If, instead of a single plate, we wish to consider a closely spaced array of vertically oriented parallel flat plates, a different formula is required. The geometry to be considered appears in Figure 1 and is typical of that for a vertically … [Read more...]
Convection and radiation loss from a fin
In last issue's column, we discussed heat loss by convection and radiation from a printed circuit board in which heat spreads in a 2-D pattern. Here, we look at a slightly simpler situation, namely that of heat transfer by a fin into the ambient air. The situation is illustrated in Figure 1, where, for simplicity, the heat is shown flowing only out of the top surface of the … [Read more...]
Convection and radiation heat loss from a printed circuit board
In last issue's column, a method for calculating the thermal conductivity of a printed circuit board (PCB) was described. Now, we look at a more complicated heat transfer process, namely the loss of heat from the surface of a PCB to the ambient air. This situation is more challenging to describe mathematically since it involves the simultaneous processes of heat spreading by … [Read more...]
Convection and radiation
In last issue's calculation corner,a simple 1-dimensional conduction calculation was described. This time, we look at the other two basic heat transfer processes, namely convection and radiation. In actual applications with multiple heat sources with complicated geometries, the effect of each of these mechanisms on the heat transfer process can be quite difficult to calculate. … [Read more...]
