Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Erciyes Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği, Türkiye
Tezin Onay Tarihi: 2017
Tezin Dili: İngilizce
Öğrenci: Natiq Abbas Fadhil AL-AMERI
Danışman: Veysel Özceyhan
Özet:
This study presents a quantitative investigation regarding the thermal performance of
inserting two types of nozzle; (a) Non-drilled nozzles, (b) Drilled nozzle with three
different pitch lengths (126, 180 and 315 mm) through a water-based TiO2 nanofluid
flowing into a horizontal tube. The considered nanofluid volume fractions are limited
from 0.2% to 2.0%. A uniform constant heat flux of 50 kW/m2was applied onto the
outer surface of the tube. The k-ω standard turbulent model was chosen to simulate
turbulent flow, and analyses were implemented for the Reynolds number ranging from
4000 to 14,000. The nanofluid flow was modeled using the mixture model as it is more
accurate than the single-phase model. The thermophysical properties of nanoparticles
and water are considered independent of temperature. The thermophysical properties of
the nanofluid were calculated with equations and empirical correlations based on the
literature. Thus, as the volume fraction of TiO2 in both the smooth tube and drilled
nozzle inserted tube rise, the heat transfer coefficient increases. While increasing pitch
length of the nozzles means decreasing the number of nozzles in the tube, yet when
using drilled nozzle, it’s higher than the non-drilled nozzle. As such, inserting more
nozzles into the tube fosters the heat transfer, but increases the pressure drop penalty.
The highest heat transfer coefficient for drilled nozzle is obtained as 72% which is
bigger than the non-drilled nozzle, and the heat transfer of non-drilled nozzle is higher
than the smooth tube about 54.5% for nanofluid flow through the smooth tube inserted
nozzle with a pitch length of 126 and volume fraction of 2.0%, and friction factor
increases approximately 5 times more than the smooth tube and less than the non-drilled
nozzle approximately 7%.