HEAT TRANSFER ENHANCEMENT USING GROOVES
Heat transfer enhancement using ribs or fins are commonly employed practices in a number of applications
including turbine cooling, heat exchangers etc. The ribs or fins enhance surface area for heat transfer and
increase flow unsteadiness and turbulence that enhance heat transfer coefficient. In the present paper, grooves
are used as turbulence enhancement devices, and an experimental study is conducted that investigates different angled grooves and combination of grooves-ribs as turbulence promoters to enhance heat transfer from the wall. The grooves are angled at 45° to the mainstream flow direction and 7 total combinations are studied. The
geometries studied are 1) V groove with the V facing upstream flow, 2) V groove with the V facing downstream
flow, 3) angled groove with smaller pitch, 4) angled groove with larger pitch, 5) combination of angled groove
with 45° angled rib, 6) combination of angled groove with transverse rib and finally 7) combination of V groove
and V rib facing upstream flow. Experiments are conducted for a Reynolds number range of 13000-55000.
Detailed and averaged heat transfer coefficient values are obtained for all the geometries. Pressure drop and
friction factor are calculated from the inlet to the exit of the grooved channel. Overall performance is calculated
from the averaged heat transfer data and friction factor. Performance of different geometries are compared and it
is found that the combination of V groove and V rib performed the best..