Experimental Investigation on the Effect a Rotational Shaft on the Thermal Behavior of a Circular Tube under Constant Heat Flux

Active and passive methods are two main mechanisms of heat transfer improvement. The active use external forces to improve transfer. This investigation evaluates the thermal frictional behavior a circular tube containing rotational shaft. Constant flux was exerted tube. fluid inlet outlet temperature as well wall tubes were measured calculate hat coefficient. Re (Reynolds) number between 800-2000. Also, dimensionless speed (Rs) had values 1,1.5, 2, 2.5 3. Results revealed that shaft could increase Nu number. Up %18. results showed significantly pressure drop friction factor. maximum increment %78 achieved for It be more efficient at low numbers speeds. it found by Reynolds being in transient regime efficiency system would improve.