**3. Channel flows**

*Inverse Heat Conduction and Heat Exchangers*

**6**

**Figure 1.**

*Different types of vortex generators used for enhancement of heat transfer. (a) Center-cleared twisted tape [4]. (b) Spring tape insert [9]. (c) Twisted tape [10]. (d) Swirl generator [12]. (e) Twisted tape with clearance at* 

*the center [13]. (f) Wavy tape with angular cuts [14]. (g) Full-length twisted tape [16].*
