LOCAL HEAT TRANSFER DISTRIBUTIONS NEAR A SHARP 180° TURN OF A TWO-PASS SMOOTH SQUARE CHANNEL USING A TRANSIENT LIQUID CRYSTAL IMAGE TECHNIQUE

Abstract

Local heat transfer distributions are presented near a sharp 180° turn of a two-pass smooth square channel using a transient technique and encapsulated liquid crystal coating. Detailed distributions of the local Nusselt numbers are given for three flow Reynolds numbers of 10,000, 25,000, and 50,000. Results show that the Nusselt numbers are much higher in the region immediately downstream of the turn compared with upstream values for all three Reynolds numbers. The regional averaged results are compared with published heat transfer data.