Addition Of Alumina Nanoparticles Research Articles

Combustion Characteristics and Application Performance of JP-10/Nano-Sized Aluminum Gel-Fueled Scramjet

Using nano-sized energetic materials as fuel additives to hydrocarbon gel fuel has gained in popularity due to the advantages of higher energy density and shorter ignition delay times. Combustion characteristics and application performance of gel fuel containing 16% wt aluminum nanoparticles were investigated on a direct-connect scramjet platform with an inflow Mach number of 2, an inflow total temperature of 1700 K, and a fuel equivalence ratio ranging from 0.6 to 1.0. The gel fuel could be stably injected and atomized efficiently by a nitrogen-assisted injector. The combustion efficiency of JP-10+Al gel fuel was 4.27% higher than that of JP-10 gel fuel, while the addition of aluminum increased the density specific impulse by 6.34%, indicating that the addition of aluminum nanoparticles indeed presented a positive effect on combustion and engine performance. The wall deposition phenomenon of gel fuel was particularly slight as compared to that of slurry fuel cases. Unlike nanoaluminum-blended slurry fuel, nanoaluminum-blended gel fuel controlled the potential risk of increasing thermal load to the least degree within the scope of existing research, with wall heat flux increasing by 7.43% solely as a result of elevated airflow temperature, indicating its advantageous application prospect.

Influence of alumina nanoparticles additives into biofuel (water hyacinth)‐diesel mixture on diesel engine performance and emissions

AbstractThe using diesel and biodiesel blends as a fuel has been a recent field of study especially with nanoparticles additives. The addition of alumina nanoparticles to biodiesel was verified to reduce emissions, while engine performance was not given great attention to evaluate the effect of blending alumina nanoparticles with the diesel and biodiesel mixture on the performance characteristics of the diesel engine. Then performance and emission tests were carried out by using different fuel samples in a single cylinder diesel engine. The brake thermal efficiency for the alumina nanoparticles (50 ppm, 100 ppm) and biodiesel blends were lower than that of biofuel (D80B20) blends, it was decreased by 2.5 %, 6.05 % respectively as compared to the blend (D80B20). The rate of carbon monoxide emissions for the two biodiesel and alumina blends were lower than that of the biodiesel blend (D80B20) and the best reduction was for the blend (D80B20N50) and was 76.3 % as compared with the biodiesel blend (D80B20). Also, the nitrogen oxides emissions for all the blends with nanoparticles were lower than that of the blend D80B20 due to shortened ignition delay and less fuel was added during the combustion which lead to reduction in nitrogen oxides emissions.

ReaxFF simulations on the combustion of Al and n-butanol nanofluid

The renewable biofuel n-butanol is an alternative to gasoline and diesel in internal combustion engines. The addition of aluminum nanoparticles (ANPs) would improve the performance of these nanofluid fuels. The reactive dynamics simulation of the ignition and combustion process of ANP/n-butanol nanofluid fuel was carried out. The combustion mechanisms of n-butanol fuel with and without ANPs, as well as the aggregation of nanodroplets and the sintering degree of nanoparticles were explored. Simulation results show that the combustion of aluminum-based n-butanol fluid fuel undergoes a three-stage: chain expansion, micro-explosion, and steady reaction. In general, the addition of ANPs improves combustion completeness and reduces the ignition delay of n-butanol. The kinetic calculations show that the activation energy of n-butanol combustion is reduced by 39.9%. A new reaction mechanism was proposed from the results: n-butanol reacts with oxygen free radicals generated by Al rather than O2. On the other hand, n-butanol prevents the aggregation and sintering of aluminum nanoparticles. Therefore, the ANP additives and n-butanol nanofluid promote mutually in the combustion. This work is expected to guide the practical application of aluminum-based alcohol fuels.

Particle adhesion induced by calcium carbonate nanoparticles at 900 °C

Particle adhesion is a typical characteristic of particulate materials. The addition of poorly packed nanoparticles to microparticles may control their adhesiveness at high temperatures. Herein, we focused on calcium carbonate nanoparticles (CaCO3 NPs) to control particle adhesion at high temperatures. The CaCO3 NPs were added to stable and less-adhesive silica and kaolin microparticles. At 900 °C, the tensile strength of the kaolin powder bed increased 6.8 times with the addition of CaCO3 NPs, but that of SiO2 did not increase. We found that the addition of CaCO3 NPs to kaolin promoted sintering of particles at high temperatures, which was responsible for the increase in tensile strength. Size and amount of CaCO3 NPs are important factors to determine the particle adhesion. The addition of alumina nanoparticles (Al2O3 NPs) to the kaolin-CaCO3 NPs system successfully suppressed the increase in tensile strength at high temperatures caused by CaCO3 NPs.

The effects of ejector adiabatic absorber on heat and mass transfer of binary nanofluid with heat transfer additives

This paper presents experimental results on the study of the effects of ejector adiabatic absorber on heat and mass transfer of binary nanofluid with heat transfer additives (2-ethyl-1-hexanol and gum Arabic). In this case, H2O/lithium bromide-alumina nanofluid was suggested due to a growing interest in absorption heat transfer working fluid for solar energy application. An experimental setup — ejector test rig — was designed to study the absorption, heat, and mass transfer rate as a result of refrigerant vapour mass flow entrained by the ejector adiabatic absorber. The study was carried out at different solution mass flowrate (0.051 to 0.17 kg/s) with three prepared sample solutions, which include pure LiBr solution, LiBr-Alumina nanofluid without heat transfer additives, and LiBr-Alumina nanofluid with heat transfer additives. The absorption rate, mass transfer coefficient, heat transfer rate, and heat transfer coefficient for the three samples were reported. On the other hand, the percentage enhancements for all the parameters — at a suitable flow rate of 0.085 kg/s — due to the addition of alumina without and with heat transfer additives were recorded. The absorption rate enhancements were 25% and 96%, the enhancement rates of mass transfer coefficient recorded were 20% and 82%, the heat transfer rate enhancements were 85% and 183%, and the heat transfer coefficient enhancements obtained were 72% and 156% with addition of alumina nanoparticles only and alumina nanoparticles with heat transfer additives respectively. Material mass balance analysis suggests that mass inflow in the ejector equals to the mass outflow from the ejector, indicating a complete absorption of the entrained refrigerant vapour beyond which falling film absorption can occur due to concentration. This article also presents experimental evidence of the capability of ejector as strong adiabatic absorber, heat, and mass transfer component, which were earlier reported using numerical models.

Liquid fuel distribution in the combustion chamber by jet impingement on small cylindrical obstacles

Homogenization of lean air-fuel mixture decreases the flame-front temperature and reduces NOx and particulate matter. Impingement of diesel jet onto an arrangement of cylindrical obstacles as a structure close to Porous media, causes high fuel dispersion in the combustion chamber. The injected fuel impinges on the first cylindrical obstacle and splits into two smaller jets and with impingement on other obstacles causes multi-jets splitting in the combustion chamber and fast mixture formation. In this paper, the injection of diesel fuel into a constant pressure chamber is simulated using CFD software. First numerical results of jet length, jet width, jet distribution angle, and spray cone angle shape, were validated with experimental data. Then, effects of obstacles diameter (1, 2 mm), injection pressure (400, 800, 1200 bar), the distance between the nozzle and first obstacle (4–12 mm) for two arrangements of obstacles (one and three cylindrical) on jet length, jet width, jet distribution angle, spray cone angle shape, and jet fuel impingement with hot obstacles impingement, have been investigated. Two new arrangements of cylinders were suggested. First, was an arrangement of three and eight cylinders for the most fuel dispersion for homogeneous mixture formation and second was an arrangement for jet leaving shape similar to liquid leaving the shape of high porosity porous medium (PM). Finally, jet impingement of alumina nano-particles and diesel fuel blend on jet length, jet width, jet distribution angle have been studied. Results show that with increasing the distance between the cylindrical obstacles, the jet length for all geometrical structures increased by about 1 mm, and the largest change for the fuel distribution angle was related to the 8d1 structure with a 19 deg increase. Fuel spray considerably does not change obstacles’ temperature during the injection and the maximum wall film mass is related to an obstacle with a diameter of 1 mm. On the other hand, the addition of alumina nano-particles to diesel fuel decreases the jet length but increases the jet width.

Nucleate pool boiling enhancement with the application of a hybrid technique involving the addition of alumina nanoparticles to stirred water above heating surface

The nucleate boiling heat transfer coefficient (HTC) can be improved using either active or passive techniques. According to the present disclosure, both techniques are used in combination. In the passive technique, nanoparticles are added to water, whereas a rotating mixer is used in the active technique to improve the boiling HTC of pure water. This study uses hybrid techniques for HTC enhancement at nucleate pool boiling regime. Experiments were carried out using circular brass as a horizontal heating surface. Different concentrations of Al2O3 nanoparticles were tested. The rotation speed of the mixer varied at 0, 350, 600, and 800 rpm. This combined technique resulted in 58.8% enhancement in HTC at 280 kW/m2 heat flux and 0.03% nanoparticle concentration. By comparison, the HTC was enhanced by 23.6% when nanoparticles were added without a mixer, whereas the enhancement ratio was 27.1% when a mixer was used in the absence of nanoparticles under the same conditions.

Combustion characteristics of a single droplet of hydroprocessed vegetable oil blended with aluminum nanoparticles in a drop tube furnace

This study examines the burning characteristics and disruptive burning phenomena of single droplets of aluminum nanoparticles (n-Al) stably suspended in a biofuel (HVO). The biofuel used in the present work is a promising alternative fuel already tested in the aviation sector to reduce greenhouse gas and pollutant emissions. Experiments were conducted with two particle sizes (40nm and 70nm) and two particle concentrations (0.5 wt.% and 1.0 wt.%) to study its influence when added to the biofuel. The effect of size and concentration of the aluminum nanoparticles was studied at 1100 °C in a drop tube furnace. This experimental facility allows the study of combustion characteristics of falling droplets, ensuring there is no influence of the supporting fiber on the burning rate and disruptive burning phenomena occurrence. A CMOS high - speed camera coupled with a high magnification lens was used to evaluate the droplet size, burning rate, and micro-explosions. Based on this procedure, pure biofuel droplets were compared with those of biofuel blended with nanoparticles. The results suggest that the combustion characteristics of pure HVO can be enhanced with the addition of aluminum nanoparticles. Furthermore, by decreasing the particle size, a slight increase in the burning rate of nanofuels was noticed. Additionally, an increase in the particle concentration leads to a pronounced increase in the burning rate. The particle concentration also influences the delay and intensity of micro-explosions, disruptive burning phenomena detected at the end of the droplet lifetime.

Impact of porous complicated fin and sinusoidal-heated wall on thermogravitational convection of different nanofluids in a square domain

Porous fins due to high extended heat transfer surface are widely used in different engineering devices including heat exchangers, solar collectors, and chemical reactors. Location of these fins within the working area can be very manifold. Therefore, the present research deals with computational analysis of complicated porous fin influence on nanofluid flow and heat transfer within the heated/cooled cabinet where one vertical wall is kept at non-uniform sinusoidal temperature. The considered fin consists of the mounted porous part at the bottom adiabatic wall and inner porous zone. Investigation has been performed using the boundary-value problem for the partial differential equations formed on the basis of the conservation laws using the experimentally-based correlations for thermal properties of nanofluid. Employing the finite difference techniques the useful results have been obtained illustrating an impact of the inner porous part penetration, location of this part and nanoparticles concentration. It has been ascertained that vertical position and penetration of internal porous block can be efficacious characteristics for the heat transfer augmentation. Moreover, an addition of alumina nanoparticles suppresses the heat transfer and convective flow.

Designing a new heat sink containing nanofluid flow to cool a photovoltaic solar cell equipped with reflector

BackgroundToday, one of the concerns is to reduce the efficiency of photovoltaic solar cells as their temperature rises. Therefore, cooling photovoltaic is one of the challenges that will be addressed in this article. In this paper, the cooling of a photovoltaic cell by a newly designed heatsink is numerically investigated. MethodTwo nanofluids were used to cool the heatsink. The heatsink consists of an Aluminum cover and two main parts in which there are numerous channels with zigzag walls. Moreover, the two-phase mixture method was employed to simulate the nanofluids flow based on finite volume method. The performance of the heatsink and photovoltaic were studied for concentration of the nanoparticles at different Reynolds numbers. FindingsUsing nanofluids increases the heat transfer coefficient but also increases the required pumping power. By adding 2% alumina at the Reynolds number of 150, the heat transfer coefficient increases by 83%. Furthermore, Al2O3/H2O nanofluids has better thermal resistance and temperature uniformity than CuO/H2O nanofluids for heatsink and photovoltaic. The addition of alumina nanoparticles increases the thermal efficiency of photovoltaic while the addition of copper oxide nanoparticles reduces it. Moreover, by increasing the Reynolds number from 50 to 150, the thermal efficiency increased by 7%.

Investigation of surface strain by digital image correlation and charge trap characteristics of epoxy alumina nanocomposites

Epoxy alumina nanocomposites were fabricated through shear mixing of alumina nanoparticles in to epoxy resin under optimum process conditions for its potential application as insulator in transformer. The fundamental insight in to the influence of ageing of nanocomposite insulator due to its continuous exposure to UV irradiation and water in terms of their charge trap characteristics was explored. The surface potential decay and strain variation of nanocomposite samples were measured by using Electrostatic voltmeter and Digital Image Correlation technique (DIC), respectively. Diffusion of water into epoxy alumina nanocomposite is less compared with pure epoxy resin. It has been observed that surface potential decay rate and trap depth have shown increasing and decreasing trend, respectively, with the addition of alumina nanoparticles in to epoxy resin. The UV and water aged nanocomposites exhibited a decreasing trend of surface potential decay rate and the governing reasons could be due to surface damage causing increase in deep trap formation. The tensile strength and stiffness of the samples have increased with the addition of alumina nanoparticles in to the epoxy resin. It could be due to the better bonding of alumina particles with epoxy resin. The surface strain induced in to the sample during tensile loading and the surface potential decay rate of nanocomposite has shown a direct correlation, as observed in the present work.

Interfacial phase of nylon 6 strongly adsorbed on alumina particles

The interfacial phase structures of nylon 6 with alumina nanoparticles were investigated by X-ray diffraction measurements, infrared spectroscopy, and differential scanning calorimetry for composites with high weight fractions (30–70%) of alumina. The melting and crystallization temperatures were decreased by the addition of alumina nanoparticles. Changes in the infrared spectra of the composites suggested that the alumina nanoparticles strengthened the hydrogen bonds of nylon 6 at their interfaces. The composites were dispersed in formic acid, which is a good solvent of nylon 6, and the precipitates were collected by centrifugation. The infrared spectrum and the results of thermal gravimetric analysis suggested the presence of nylon 6 in the precipitate even after washing with formic acid. These results indicate the existence of an interfacial phase where nylon 6 is strongly adsorbed onto alumina nanoparticles, and its crystallization behavior and structure formed by the hydrogen bonds were affected by the interfacial interaction. Composites of nylon 6 and large amounts of alumina nanoparticles were prepared to investigate nylon 6 at its interface with alumina. DSC curves obtained by heating and cooling the slowly cooled samples indicate decreases in melting and crystallization temperatures. The melting enthalpy and XRD patterns show a decrease in the degree of crystallization with the addition of alumina. The IR spectra suggest that hydrogen bonds were enhanced at the interface.

Investigation on the electrical, thermal and mechanical properties of silicone rubber nanocomposites

Addition of alumina nano particles to silicone rubber (SR) has shown a significant improvement in electrical, mechanical and thermal properties of the SR nanocomposites. Static contact angle and water droplet-initiated corona inception voltage exhibited a marginal change on inclusion of nano alumina into SR matrix. Alumina filler improved the corona ageing resistance of the composites; however, a marginal reduction in the rate of hydrophobicity recovery is observed. Laser induced breakdown spectroscopy proved as an effective tool to rank the performance of the SR nano composites. Variation of crater depth with energy of laser pulse and number of laser pulses follows the exponential relation. Plasma temperature calculated by optical emission spectroscopy is in line with the amount of damage caused to the surface of the specimen by water droplet-initiated discharge. Dielectric response spectroscopic studies indicate that inclusion of nano fillers has resulted in lower interfacial polarization and lower imaginary permittivity. It is observed through dynamic mechanical analysis that the composites have higher storage modulus and the activation energy compared to base SR.

STUDY OF EFFECT Al2O3 NANOPARTICLES ON ELECTRICAL PROPERTIES OF EPOXY REINFORCEMENT BY CARBON FIBERS HYBRID COMPOSITES

In this paper was investigation the electrical properties of the epoxy "Hybrid Composites" as a function of a frequency. The composites constituents were epoxy using a matrix with reinforcement ratio (1:3) and volume fractions as (25% wt). The "Hybrid Composite" samples were prepared by addition alumina nanoparticles on the epoxy composites reinforced by carbon fibers with different volume fractions (0.1,0.3,0.5,0.7)w% by "Hand Lay-Up Molding". The experiments were performed to measure the electrical properties "Dielectric Constant, Dissipation Factor and Electrical Conductivity" in frequency range (10Hz-1MHz). The study showed that the reinforcement process resulted in an increase in the dielectric constant values of all manufactured models, and the addition of alumina nanoparticles leads to a decrease in the values of both the dielectric constant and the dielectric loss factor with increasing frequency and for all samples and for all values listed. Alternating electrical conductivity values increase significantly with increasing frequency and for all samples when alumina nanoparticles are added.

Influence of aluminum nanoparticles and binders on the laser initiation of cyclotrimethylenetrinitramine

Aluminum nanoparticles were added into cyclotrimethylenetrinitramine (RDX) to enhance the laser absorption and lower the initiation energy of pulse laser. Polyvinyl acetate (PVA), polyvinyl butyral (PVB), and fluororubber (F2314) were added into RDX as binders to prepare the RDX-based composite explosives with desirable mechanical behavior. The influence of aluminum nanoparticles and binders on the light absorption, thermal behavior, laser initiation energy and the electron temperature in aluminum plasma were investigated using reflectance spectroscopy, differential scanning calorimetry, laser initiation and laser-induced breakdown spectroscopy. Results showed that the addition of aluminum nanoparticles could prominently lower the laser initiation energy of the RDX-based explosives. The RDX doped with 2.0% aluminum nanoparticles could be reliably initiated with 1.5 J/cm2 laser energy (1064 nm, 8 ns). The laser initiation energy increased to 1.7, 2.4 and 2.9 J/cm2 with the additions of 0.5%, 1.0% and 2.0% F2314 binders, respectively. When the addition of PVA and PVB increased to 2.0%, the RDX-based explosives couldn’t be initiated by pulse laser. When the pulse laser radiated on the surface of the RDX-based composite explosives, the aluminum nanoparticles absorbed the laser energy and were heated to high temperature to initiate the explosives. The addition of binders can provide desirable mechanical behavior, but the laser initiation energy increased because the heat transmission from aluminum nanoparticles to RDX was hindered.

Poly(ionic liquid) iongel membranes for all solid-state rechargeable sodium battery

Sodium-ion is seen as one of the most promising alternative technologies to the current lithium-ion batteries. Sodium is cheap and widely available in comparison to lithium, however new electrode and polymer electrolyte materials need to be found to improve the performance and security of sodium batteries. In this work, we show a new iongel electrolyte with excellent properties for an all solid-state rechargeable sodium batteries. This iongel membrane is based on the poly(dimethyldiallylammonium) polyDADMA-TFSI poly(ionic liquid), N-Propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (C3mpyrFSI) and sodium bis (fluorosulfonyl)imide (NaFSI) the salt. PolyDADMA-TFSI can incorporate up to 50 wt% of C3mpyrFSI ionic liquid content in a self-standing membrane with high ionic conductivity. The increasing the NaFSI concentration in this electrolyte was beneficial for the sodium transference number but detrimental for the ionic conductivity of the membranes. The addition of alumina nanoparticles further improved the membrane mechanical robustness without affecting significantly the ionic conductivity. The iongel membranes presented a wide electrochemical window of 5 V thereby supporting sodium electrochemistry as demonstrated by excellent symmetric sodium cell cycling at 70 ᵒC for 60 cycles. Finally, the electrochemical performance of the optimum composition iongel was evaluated in sodium all solid-state battery using a sodium metal anode and NaFePO4 as the cathode material. The cells show good capacity retention with high coulombic efficiency (>97%) at C rates between C/20 and C/5 achieving 110 mAhg−1 at C/20.

Characterisation and corrosion study of electroless Nickel-Boron coating reinforced with alumina nanoparticles

Abstract This investigation deals with the study of 1 g/l alumina reinforced electroless Ni-B coatings on a low carbon steel substrate. Reinforced coatings were prepared from the as-received nano powders. The alumina nano particles were ultra-sonicated before being introduced into the coating bath. The reinforced coatings exhibited an improvement in hardness, and corrosion resistance. A significant increase of nearly 10%, was observed in case of the hardness of the reinforced coatings. Corrosion potential increased by about 6% with the addition of alumina nano particles. The agglomerated nano particles seem to embed in the nodular boundaries of the cauliflower like Ni-B morphology and in inter nodular porosities. This, in turn, improved the corrosion resistance by forming an intimate sacrificial layer on the vulnerable substrate material.

Effect of nanoparticle on emission and performance characteristics of a diesel engine fueled with cashew nut shell biodiesel

ABSTRACTHigh-rise in the air pollution levels due to combustion of the fossil fuel gives us the opportunity to discover environmentally friendly and clean fuels for the engines. Biodiesel originated from cashew nut shell oil through transesterification process can be blended or used as a neat fuel in unmodified engines. This work investigates the effect of alumina nanoparticles on emission and performance characteristics of cashew nut shell biodiesel. Neat cashew nut shell biodiesel prepared by conventional transesterification is termed as BD100 and biodiesel prepared by modified transesterification with the addition of alumina nanoparticles is termed as BD100A. Experimental results on unmodified diesel engine revealed that emission parameters such as CO, HC, NOx, and smoke were decreased by 5.3%, 7.4%, 10.23%, and 16.1% for BD100% and 8.8%, 10.1%, 12.4%, and 18.4% for B100A, respectively, compared to diesel fuel. At full load conditions, compared to diesel fuel, the BTE dropped by 1.1% and 2.3%, whereas the BSFC increased by 3.8% and 5.1% for B100A and B100 correspondingly.

The effect of alumina nanoparticles on the thermal properties of PMMA: a molecular dynamics simulation

ABSTRACTMetal oxides, as one of the most promising flame retardant additives, improve the fire retardant and the thermal stability properties of polymers. In the present study, molecular dynamics (MD) simulations based on the united atom model were applied to study the effect of alumina nanoparticles on the density, thermal conductivity, heat capacity, and thermal diffusivity of isotactic poly(methyl methacrylate) (is-PMMA). Thermal diffusivity of PMMA and PMMA/alumina nanocomposite were investigated through calculating thermal conductivity, density and heat capacity in the range of 300–700 K. Heat capacity can be calculated using fluctuations properties of energy. Thermal conductivity was calculated through the nonequilibrium molecular dynamics (NEMD) simulation by Fourier’s law approach. Our results show that the addition of alumina nanoparticles decreases the heat capacity and increases the glass transition temperature (Tg), thermal conductivity and thermal diffusivity of the PMMA. Therefore, the addition of alumina nanoparticles to PMMA improves the fire retardancy of the polymer. In addition, we illustrate the links between the intermolecular and bulk properties of PMMA in the presence of the alumina nanoparticles.

Numerical study of a regenerative counter flow evaporative cooler using alumina nanoparticles in wet channel

The use of Maisotsenko Cycle (M-Cycle) has enhanced the domain of evaporative cooling technologies to sub-wet bulb temperature cooling while ensuring moisture control. Several studies have demonstrated the use of cross-flow heat & mass exchanger (HMX) offers higher cooling capacity; however, it has lower cooling effectiveness and Energy Efficiency Ratio (EER). In contrast, a counter-flow (HMX) offers high cooling effectiveness with lower cooling capacity. In this paper, the performance of counter-flow HMX is enhanced by addition of alumina nanoparticles in feed water due to enhanced heat and mass transfer characteristics of nanofluids compared to original base fluid. Here, a mathematical model is formulated by incorporating the nanofluids in a selected control volume. The developed model is solved numerically on a discretized HMX length. Initially, the model is benchmarked against previously published results using water as base fluid. A comparison between HMX performance using water and alumina nanofluid is performed in terms of Performance Enhancement Ratio (PER). PER indicates 1–18% increase in cooling effectiveness, 18–43% increase in cooling capacity and 9–19% increase in EER by using alumina in water when working air temperature is increased from 20 °C to 45 °C. Similarly, an increase in PER is also observed by changing air velocity. Increase of 41% is observed in cooling capacity and 18% increase in EER is observed by changing particle volume fraction from 0 to 2%. This research identifies ways to reduce the carbon emissions of a building by increasing the energy efficiency of existing evaporative cooling technology using nanofluids.