ABSTRACT
This chapter discusses the relationships applicable to the most common geometrical situations are reported, independent of the specific method used to obtain them. The solution of conservation equations is obtained analytically only in the particular situation of laminar flows, with quite simple geometries. The single-phase-fluid heat transfer generally consists of two contributions: conduction through the fluid and heat transport associated to the motion of fluid particles between the wall layer and the bulkstream. Several relationships are available, referring to a great number of experimental tests performed because of the industrial relevance of this geometrical situation. A great number of studies have been dedicated recently to the heat transfer analysis of fluids flowing outside tubes, in parallel or in cross directions. The presence of grids and spacers is also of interest in the situation of single-phase flows of gas or liquid inside rod bundles. The fin type must be carefully selected owing to possible problems in the equipment cleaning.
