**5. Observations from literature review**

Twisted tape installation mixes the flow of quantities well and is thus superior to any other installation in laminar flux, as heat resistance is not restricted from laminar flow [4] to a small area near the wall. But the performance of twisted tape

**Figure 3.** *Experimental DPHE setup with twisted tape.*

depends on the fluid parameters such as Prandtl number. Due to its flexible volume, the length of a twisted band **Figure 3(a)** and **(b)** is better than the length of a full band. Twisted tape can be used effectively to increase heat transfer when designing small heat exchanges **Figure 3** for laminar flow.

Turbulent flow [5] twist tape works well up to a certain level of Reynolds but not beyond the wide range of Reynolds. The twisted tape does not work in a turbulent flow compared to a wind turbine due to the drop in pressure drop. So the performance of hot rolled tape is not very good compared to the turbulent flow wire coil. It can therefore be proved that in a turbulent environment a wire spool is a good choice. However, short twisted tapestry offers better hydrothermal performance compared to long and twisted tapestry.
