M.Sc Tezi Görüntüleme

Student:	Mete AVCI
Supervisor:	Asst. Prof. Dr. Habip ASAN
Department:	Mechanical Engineering
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University, Turkey

Title of the Thesis:	EXPERIMENTAL INVESTIGATION OF FLOW AND HEAT TRANSFER IN CONCENTRIC-SQUARE ANNULAR DUCT WITH ARTIFICIALLY ROUGHENED INNER SURFACE
Level:	M.Sc
Acceptance Date:	18/8/2003
Number of Pages:	80
Registration Number:	i1395

Summary:

SUMMARY

In this study, flow and heat transfer were experimentally investigated in concentric square annular duct with artificially roughened inner surface. The experiments were performed for hydrodynamically fully developed and thermally developing flow at constant heat flux boundary condition of inner duct and insulation boundary condition of outer duct. The pitches of roughness are fixed as 1cm, 2cm and 3cm, respectively. Experiments were carried out for Reynolds number ranging 20074 to 72443 and the fluid used was air at atmospheric conditions. By using the experimental results local heat transfer coefficient, average Nusselt number, local surface temperature, velocity profile and friction factor values were calculated and presented as a function of Reynolds number and duct length.

In order to determine the performance of duct types having several pitches of roughness and to estimate unavoidable errors in experimental results, entropy and uncertainty analyses have been performed.

Comparing with smooth duct, an enhancement of up to %70, %60 and %40 in heat transfer was obtained for 1cm, 2cm and 3cm roughness pitches, respectively. However , the friction factor increased up to %105, %100 and %95 for 1cm, 2cm and 3cm roughness pitches, respectively.

Keywords: Concentric-Square Annular Duct, Artificial Roughness, Heat Transfer Enhancement, Constant Heat Flux, Performance Analyses, Uncertainty Analyses.