Experimental Investigation of Heat Transfer Enhancement with Nanofluid and Twisted Tape Inserts in a Circular Tube

Abstract

This paper presents an experimental study to investigate the heat transfer enhancement in a horizontal circular tube using three metal oxide (ZrO 2 (80 nm), γ Al 2 O 3 (20 nm), CuO (40 nm)distilled water) nanofluids and fitted with three types of twisted tape (typical twisted tape, twisted tape with V-cut and clockwise-counter clockwise twisted tape) with twist ratios (TR=4, 6, 8). The studied concentrations of nanofluids are (φ = 0, 0.01, 0.05, 0.1, 0.5, 1, 2, 3% by volume) under fully developed turbulent flow and uniform heat flux condition.The experimental test rig includes all the required instruments to study the heat transfer enhancement. All the tests were carried out with Reynolds number range (2490-20100) and uniform heat flux (2108-9280 W/m 2 ). The experimental study also includes preparation and measurement of properties of density, viscosity and specific heat of nanofluids. The pressure drop, wall temperature, flow rate, heat flux and temperature of nanofluids.For nanofluid, the maximum enhancement in the heat transfer (Nusselt number ratio) was (7.5), and the maximum thermal performance factor was (3.9) using (CuO)-distilled water nanofluid, clockwise-counter clockwise twisted tape with twist ratio (TR=4) at Reynolds number (2490) and concentration (φ=3%). The average Nusselt number and friction factor with Reynolds number, nanofluid concentration and twist ratio were correlated for each type of the used nanofluid. ‫دائري‬ ‫أنبوب‬ ‫داخل‬ ‫الملتويت‬ ‫األشرطت‬ ‫مع‬ ‫الذقت‬ ‫متناهيت‬ ‫الموائع‬ ‫باستخذام‬ ‫الحرارة‬ ‫انتقال‬ ‫لتحسين‬ ‫تجريبيت‬‫دراست‬ ‫الخالصت‬ ٍِ ‫أّىاع‬ ‫ىثالثخ‬ ‫اىجشَبُ‬ ‫و‬ ‫اىحشاسح‬ ‫الّزقبه‬ ‫ػَيُخ‬ ‫دساصخ‬ ‫إجشاء‬ ‫رٌ‬ ‫اىجحث,‬ ‫هزا‬ ‫فٍ‬ ‫اىَيزىَخ‬ ‫األششطخ‬ (typical, V-cut and clockwise-counter clockwise) ( ‫اىزىاء‬ ‫ّضت‬ ‫ثثالثخ‬ ‫رصُْؼهب‬ ‫رٌ‬ TR=4, 6, 8 ‫داخو‬ ,) ‫هٍ‬ ‫ٍؼذُّخ‬ ‫ألمبصُذ‬ ‫اىذقخ‬ ‫ٍزْبهُخ‬ ‫اىَىائغ‬ ٍِ ‫أّىاع‬ ‫ثالثخ‬ ‫ثبصزخذاً‬ ‫اىَْبرج‬ ‫مو‬ ‫اخزجبس‬ ‫رٌ‬ ‫أفقٍ.‬ ‫دائشٌ‬ ‫أّجىة‬ (ZrO 2 (80 nm), γ Al 2 O 3 (20 nm), and CuO (40 nm))-distilled water ‫وثزشامُز‬ (φ = 0, 0.01, 0.05, 0.1, 0.5, 1, 2, 3% by volume)

Computational Single and Multiphase Approaches to Investigate the Hydrothermal Behavior of Hybrid Nano-fluid in Plain and Wavy Tubes

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“…For Re 2 ×10 4 (22) For Re 2 ×10 4 (23) Petukov [52] equation for the turbulent region 4) (24) For 3000 < Re < 5×10 6 .…”

“…For expensive empirical investigations, the evaluation of hydrothermal properties of Nano-fluids significantly relies on their proper modeling. The appropriate simulation of Nano-fluids demands an excellent knowledge of the physical phenomena which causes augmentation in the thermal conductivity [5,6]. There are several mechanisms responsible for developing thermal conductivity.…”

Modeling and analysis of thermoelectric atmospheric water generation in the economic city of Iraq

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