Sandesh S. Chougule

Thermal Performance of Automobile Radiator Using Carbon Nanotube-Water Nanofluid—Experimental Study

In the present study, the convective heat transfer enhancement of carbon nanotube (CNT)-water nanofluid has been studied experimentally inside an automobile radiator. Heat removal rate of the coolant flowing through the automobile radiators is of great importance for the optimization of fuel consumption. In this study, four different concentrations of nanofluids in the range of 0.15–1 vol. % were prepared with the addition of CNT nanoparticles into water. The CNT nanocoolants are synthesized by functionalization (FCNT) and surface treatment (SCNT) method. The effects of various parameters, namely synthesis method, variation in pH values and nanoparticle concentration on the Nusselt number are examined through the experimental investigation. Results demonstrate that both nanocoolants exhibit enormous change Nusselt number compared with water. The results of functionalized CNT nanocoolant with 5.5 pH exhibits better performance compared to the nanocoolant with pH value of 6.5 and 9. The surface treated CNT nanocoolant exhibits the deterioration in heat transfer performance. In addition, Nusselt number found to increase with the increase in the nanoparticle concentration and nanofluid velocity.

Thermal Performance of Nanofluid Charged Heat Pipe With Phase Change Material for Electronics Cooling

The paper reports the thermal performance of a nanofluid (MCNT/water) charged heatpipe with phase change material (PCM) as energy storage material (ESM) for electroniccooling. The adiabatic section of heat pipe is covered by the PCM stored in a containermade of acrylic material. Here, paraffin is used as PCM. PCM can absorb and releasethermal energy depending upon the fluctuations in the heating load. Tests are conductedto obtain the temperature distributions in PCM during charge/discharge processes. Pres-ent study utilizes two different ESM (water and paraffin), different fan speeds and heatingpowers in the PCM cooling module. The cooling module with heat pipe and paraffin asESM found to save higher fan power consumption compared to the cooling module thatutilities only a heat pipe. [DOI: 10.1115/1.4028994]Keywords: heat pipe, nanofluid, phase change material, electronics cooling

Comparative Study on Heat Transfer Enhancement of Low Volume Concentration of Al2o3–Water and Carbon Nano-Tube–Water Nano-Fluids in Transition Regime Using Helical Screw Tape Inserts

This study reports the comparison of heat transfer and friction factor characteristics of helical screw inserts in Al2O3–water and carbon nano-tube–water nano-fluids through a straight pipe in transition regime with constant heat flux boundary condition. Experiments were carried out by using 0.15% volume concentration of Al2O3–water and carbon nano-tube–water nano-fluid with helical tape inserts of twist ratio, TR = 1.5, 2.5, and 3. The thermal performance of helical screw tape inserts with the carbon nano-tube–water nano-fluid is found -to be higher when compared to the Al2O3–water nano-fluid. In addition, the maximum enhancement in heat transfer was obtained for the carbon nano-tube–water nano-fluid with helical tape inserts of twist ratio 1.5. The increase in pressure drop of the Al2O3–water nano-fluid with helical screw tape inserts is found to be higher compared to the carbon nano-tube–water nano-fluid helical screw tape inserts at lower value of twist ratio.

Experimental Investigation of Heat Transfer Augmentation in Automobile Radiator With CNT/Water Nanofluid

The trend toward higher engine power leads to larger radiators in automobile sector and increased frontal areas, resulting increased fuel consumption. Heat transfer of coolant flow through the automobile radiators is of great importance for the optimization of fuel consumption. Compaq cooling system can be manufactured by introducing nanocoolant with in automobile radiator. In this paper, heat transfer of CNT based nanocoolant has experimentally compared to that of pure water in an automobile radiator. Four different concentrations of nanofluids in the range of 0.15–1 vol. % have been prepared by the addition of CNT nanoparticles into the water. The test liquid flows through the radiator consisted of vertical tubes with rectangle cross section and air makes a cross flow inside the tube bank with constant speed. The CNT nanocoolants are synthesized by functionalization CNT (FCNT) and surface treatment (SCNT) method. The effects of type of nanofluid, variation in pH and nanoparticle concentration on the Nusselt number are deeply investigated. Results demonstrate that both nanocoolant show enormous change Nusselt number in comparison with water. The results of functionalized CNT nanocoolant with 5.5 pH show better performance than 6.8 and 9 pH nanocoolant. The surface treated CNT nanocoolant show results deterioration in heat transfer performance. Furthermore, increasing the nanoparticle concentration and nanofluid velocity enhances the Nusselt number.© 2013 ASME

Model of heat conduction in hybrid nanofluid

A theoretical study model has been proposed for predicting the thermal conductivity of hybrid nanofluid. Present model takes an important step towards understanding the heat conduction in hybrid nanofluids. Effect of surface area and size of nanoparticles is considered. The model predictions are in good agreement with experimental data over a wide range of particle sizes, volume fractions and their thermal conductivity of individual nanoparticles of hybrid nanofluid.

Performance of Carbon Nanotubes–Water Nanofluid Charged Wickless Heat Pipe Flat Plate Solar Collectors Having Different Filling Ratio

An experimental study was carried out to investigate the thermal performance of solar heat pipe collector at outdoor test condition. The thermal performance of wickless heat pipe solar collector was investigated by using CNT–water nanofluid. Carbon nanotubes (CNT) nanoparticles with diameter 10–12 nm and 0.1–10 μm length were used in the present experimental investigation. The effects of various filling ratio (F.R.) (50%, 60%, and 70%) and coolant flow rate on thermal performance were discussed in this study.

A review of heat pipe with nanofluid for electronic cooling

A heat pipe is an important tool for effective cooling performance of the electronic devices. The main focus of this paper is to review applications of heat pipe in electronic system. Miniaturization of chips and increasing processing speed decreases the heat transfer surface area and generates very high heat fluxes resulting in large temperature rise in electronics devices. Therefore, for an effective cooling heat pipe is a better selection because of its high efficiency and reliability. A major part of this review paper is allocated to applications of different types of heat pipe and modern trends in heat pipe technology. Nanofluids are dilute suspensions of nanoparticles composite materials with the specific aim of increasing the thermal conductivity of heat transfer fluids. Authors also analyzed some of the applications of heat pipes with nanofluid for electronic cooling.

Heat Transfer Characteristics of CuO-Water Nanofluids Jet Impingement on a Hot Surface

In present study, an experimental investigation has been carried out to analyze the heat transfer characteristics of CuO-water nanofluids jets on a hot surface. A rectangular stainless steel foil (AISI-304, 0.15 mm thick) is used as a test surface is electrically heated to obtain the required initial temperature. The distribution of heat flux on the target surface is evaluated from the recorded thermal images during transient cooling. The effect of nanoparticle concentration and Reynolds number of the nanofluids jet impingement heat transfer characteristics is studied. Tests were performed for an initial surface temperature of 500°C, Reynolds number (5000≤Re≤13000), CuO-water nanofluids concentration (Φ= 0.15%, 0.6%) and nozzle to plate distance was l/d= 4.Copyright