B.Sc. Mechanical Engineering Thesis • Nov 2017 – Oct 2018

Heat Transfer Performance of Internally Finned Tubes Using Water and Air

Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET)

Thesis Abstract

Heat transfer performance of a smooth circular tube versus a tube with four longitudinal, equally spaced internal fins was experimentally investigated using water and air as working fluids. Nichrome wire wrapped uniformly around the tube outer diameter served as the heat flux source, while fully developed turbulent airflow and laminar water flow operated as heat sinks.

Wall temperature, bulk fluid temperature, and longitudinal pressure drops were logged for Reynolds numbers ranging from 7,000 to 12,000 (regular tube) and 3,000 to 4,000 (finned tube) in air, and 40 to 100 in water. Heat transfer coefficients and Darcy friction factors demonstrated substantial thermal augmentation attributable to the increased effective wetted perimeter and secondary flow swirl in the finned geometry.

Experimental Rig & Instrumentation

Experimental Setup Schematic

Schematic of Heat Transfer Loop

Fabricated Test Tube

Fabricated Nichrome-Wrapped Rig

Experimental Data Acquisition

Instrumentation & Thermocouples