Experimental development of tubseide heat transfer correlations for laminar flow with and without inserts.

• Main Author: Guido, Joseph D.
• Other Authors: Marto, P.J.
• Language: en_US
• Published: Monterey, California. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/23668

Approved for public release; distribution is unlimited === An experimental study of laminar flow heat transfer of an ethylene glycol/water mixture in an electrically heated horizontal tube using wire mesh (HEATEX) and twisted tape inserts was investigated. Twelve thermocouples, inserted in the tube wall at four longitudinal locations, enabled a mean inside experimental heat-transfer coefficient to be accurately measured. A constant wall heat flux boundary condition was placed on the wall by wrapping six 200 W flexible heater tapes tightly around the tube. The ethylene glycol/water mixture provided a coolant Reynolds number between 200-5000 and a Prandtl number between 30-140. Two smooth inside diameters and a roped tube profile were tested with and without the inserts. Heattransfer correlations for tubes without inserts were developed and compared with theory for both thermally and hydrodynamically developing flow. Correlations were also developed for the two types of inserts.