The influence of width-to-pitch ratio t/p and width-to-height ratio t/e of ribs upon heat transfer and total pressure loss of rectangular grid-ribbed channel was studied experimentally.Two groups of experimental models were used.The first group was consisted of two ribbed plates with ribs at 45° and -45° to the axis of the channel

respectively

named as 45/45 model.The second group of experimental models was consisted of two plates with rib angle at 45° and

-60° and named as 45/60 model.For these models

t/e varies among 0.25

0.3

0.5

and t/p varies among 0.25

0.33

0.5.The Reynolds numbers varied from 0.5×105 to 1.5×105.The results showed that the models with t/p=0.5 and t/e=0.3 got the best heat transfer enhancement

but also caused highest total pressure drop.The 45/45 model and 45/60 model have similar heat transfer performance

while the latter caused much higher total pressure loss than the former.