Averaged Nusselt Number Correlations of Cylinders in Cross Flows
Note 1: averaged Nusselt number correlations for the circular cylinder flows can be found in chapter 10-5. Correlations for other noncircular cylinders in cross flow can also be found in this chapter (see Table 10-3).
Note 2: Heat transfer between a tube bank (tube bundle) and cross flow is given in many HT textbooks (for example: see chapter 7 of “Introduction to Heat Transfer” by Incropera & DeWitt. The configuration is important for many practical applications, for example, the multiple pass heat exchanger in a condenser unit. The use of tube bank can not only save the operating space but also can enhance heat transfer. The wake flows behind each row of tubes are highly turbulent and can greatly enhance the convective heat transfer. In general, one can find an averaged convection coefficient using empirical correlation.
Note 3: Because of its compactness, pressure drop across a tube bank can be also significant and warrants careful design consideration.