NUMERICAL INVESTIGATION OF THERMAL AND HYDRAULIC PERFORMANCE A TWISTED TUBE MODIFIED BY USING “CUO/WATER” NANOFLUID


Thesis Type: Postgraduate

Institution Of The Thesis: Erciyes University, Mühendislik Fakültesi, Makina Mühendisliği, Turkey

Approval Date: 2020

Thesis Language: English

Student: Mohammed Ahmed Mousa AL-HAMEEDAWI

Supervisor: Veysel Özceyhan

Abstract:

In this study, several numerical simulations were constructed in order to enhance the heat transfer performance by exploiting smooth and twisted tubes with three different pitch lengths was (50mm, 100mm, 250mm). Water was selected as base fluid for analysis, and the (CuO-Water) nano-fluids effect was tested on the heat transfer through a circular tube in order to improve the thermal and hydraulic performances. The nano-fluid used was a single-phase of four different volume fractions: 1, 2, 3, and 4%. The analysis was experimented for Reynolds number values between 6000-40000. Constant uniform heat flux of 50,000 W/m2 was applied to the outer surface of the test tube. Besides; kepsilon standard turbulence model was adopted through the use of CFD (ANSYS) program. The inlet fluid temperature was taken as 293K and a constant hydraulic diameter of 26.9mm was considered. The optimum results (Nu = 443.76, h=12129.98 W/m2 , f = 0.1582, ∆p = 2782.85 Pa, PEC=2.39) obtained were at pitch length of 50 mm, Reynolds number of 35613 and volume fraction of 4% (CuO-Water) in base fluid. Finally, The results in terms of thermal and hydraulic performances showed decreasing Nusselt number, heat transfer coefficient, friction factor and pressure as the number of pitches length in twisted tube increased. In addition, the thermal and hydraulic characteristics increased too when increasing the value of CuO-water nano-fluid fraction.