Publications
Impact of CuO+H2O nanofluid on the cooling towers performance with varying packing densities
Mar 19, 2025Journal Results in Engineering
DOI https://doi.org/10.1016/j.rineng.2025.104664
Issue 26
In this paper, the cooling tower (CT) performance has been experimentally investigated. Four types of packing with varying numbers of layers have been employed to investigate the impacts of packing density on the CT performance when using Copper Oxide (CuO) nanofluid as a working fluid. Three different concentrations (1, 3, and 5 %) of CuO+H2O nanofluid have been evaluated to assess the influence of nanoparticle concentration on the CT performance. The results show that adding more packing layers improves the thermal performance of the CT, regardless of the use of pure water or nanofluid. The effect is more pronounced when CuO+H2O nanofluid is employed. Furthermore, at a volume concentration of 5 % CuO+H2O nanofluid, the water temperature differential, cooling tower characteristic, and cooling efficiency increased by 15.3, 7, and 12.5 %, respectively, compared to pure water. However, the tower characteristic tends to increase for lower concentrations (3 %), but may decrease for higher concentrations (5 %). Nonetheless, the tower characteristic may ultimately increase for all concentration levels. Additionally, the impact of CuO+H2O nanofluid on temperature difference becomes more pronounced as the packing density increases. For example, the temperature differential of the water increases by around 7.5 % and 24.3 % for 7 and 20-layer packing, respectively. These findings suggest that utilizing CuO+H2O nanofluid as a circulating fluid in place of pure water can lead to improved thermal performance of CTs.
Parametric analysis for performance and emissions of gasoline direct injection engine using mathematical modelling
Oct 28, 2024Journal Engineering and Technology Journal
Issue 42
Volume 1
Bernoulli-Euler beam theory (BEBT) overestimates their critical buckling load. This paper has derived a cubic polynomial shear deformation beam buckling theory (CPSDBBT) from first principles using the Euler-Lagrange differential equation (ELDE). It develops closed-form solutions to differential equations using the finite sine transform method. The formulation considers transverse shear deformation and satisfies the transverse shear stress-free boundary conditions. The governing equation is developed from the energy functional, ∏, by applying the ELDE. The domain equation is obtained as an ordinary differential equation (ODE). The finite sine transformation of the ODE transforms the thick beam, which is considered an algebraic eigenvalue problem. The solution gives the buckling load Nxx at any buckling mode n. The critical buckling load Nxx cr occurs at the first buckling mode and is presented in depth ratios to span (h/l). It is found that and agrees with previous solutions using shear deformable theories. For / hl = 0 10 . , (a moderately thick beam), the Nxx cr is 2.50% lower than the value predicted using BEBT, confirming the overestimation by BEBT. The Nxx cr / hl = 0 10 . , agrees with previous solutions, implying the shear deformation has been adequately accounted for, and the BEBT overestimates the Nxx cr. The value of Nxx cr found agrees with previous values in the literature.
Effects of Nozzle Diameter and Holes Number on the Performance and Emissions of a Gasoline Direct Injection Engine
Mar 1, 2024Journal International Journal of Thermodynamics
DOI 10.5541/ijot.1272871
Issue 1
Volume 27
The goal of the current study is to estimate how a gasoline direct injection (GDI) engine's performance and emissions are affected by the fuel injector nozzle diameter and hole number of its injectors. A thermodynamic mathematical modelling has been created utilizing a software program written in the MATLAB language to simulate the two-zone combustion process of a four-stroke direct injection engine running on gasoline at (Rotation Engine Speed 3000 revolution per minute (rpm), 40 MPa injection pressure, compression ratio 9.5, and spark timing 145°). The first law of thermodynamics, equation of energy, mass conserving, equation of state, and mass fraction burned were all used in the creation of the software program. The study was carried out at five different nozzle diameters (0.250, 0.350, 0.450, 0.550, and 0.650 mm) and nozzle hole numbers (4,6,8,10,12). The results show that the GDI engine's performance and emissions are significantly influenced by variations in nozzle hole diameter and number. It was shown that engine power, heat transfer, cylinder pressure, and temperature increased with increasing nozzle hole diameter and number of nozzle holes and the maximum value was seen with nozzle hole diameter 0.650 mm and (12) holes. The lowest value for the nozzle hole diameter and number of holes was found to be 0.250 mm and 4 nozzle holes, which resulted in the lowest emissions of carbon monoxide CO and nitrogen monoxide NO. The study was also conducted for different operating conditions (Rotation Engine speed of 1000, 2000, 3000, 4000, 5000 rpm ,35 MPa injection pressure , compression ratio of 11.5 , and spark timing of 140° ) and the same nozzle diameters and nozzle holes number mentioned previously to estimate the maximum values for temperature, pressure, power , heat transfer and emissions . The results of the second part of the study showed that the highest of maximum values of temperature, pressure, and emissions were at of 1000 rpm, a nozzle diameter of 0.650 mm, and (12) holes. The highest values for maximum power at 4000 rpm, a nozzle diameter of 0.650 mm and (12) holes, while the highest maximum values for heat transfer are at 5000 rpm, a diameter of 0.65mm and (12) holes
MATHEMATICAL MODELING AND EVALUATION OF FUEL INJECTION PRESSURE EFFECTS ON THE PERFORMANCE AND EMISSIONS OF GASOLINE DIRECT INJECTION ENGINE
Dec 1, 2023Journal Journal of Engineering Science and Technology
Many parameters affect the performance of the gasoline direct injection (GDI) engine. Among these parameters, the fuel injection pressure plays a significant role in fuel supply and combustion quality. The present study aims to estimate how a GDI engine's performance and emissions are affected by the injection pressure with other parameters and help to determine the optimal injection pressure for efficient GDI engine operation. Thermodynamic mathematical modelling has been created utilizing MATLAB software. The thermodynamics first law, energy equation, conservation of mass, state equation, and mass fraction burned were all used to create the software program. Pressures used for fuel injection ranged from 5 to 45 MPa. According to the findings, nozzle injection pressure variations considerably impact the GDI engine's output and emission. It was shown that engine power, heat transfer, cylinder pressure, and temperature increased by injection pressure and maximum value with injection pressure 45 MPa. So, fuel injection systems must be designed to withstand high pressures to benefit from high-pressure fuel injection as much as possible. When fuel injection pressure variation with versus engine speed and nozzle holes number. Maximum engine power per cycle obtained when injection pressure 45 MPa and 3000 rpm with eight holes number. Carbon monoxide CO and Nitrogen monoxide NO emissions were found to be lowest for injection pressure 5 MPa.
Experimental Investigation on the Influence of Duct Material on the Heat Gain to Air Flow
Jul 23, 2019Journal Conference Paper
Publisher IEEE
DOI 10.1109/IEC47844.2019.8950606
Issue Pages 64 - 67
In this study, the influence of the duct material and insulation on the air heat gain is experimentally investigated. The objective of this study is to present the results of experimental evaluating of the heat gained by the air that flows through a square duct using several materials and insulations. The materials were galvanized steel duct without insulation, galvanized steel duct with 25 mm glass wool insulation and foam duct with a density of 50 kg/m3. Also, for each case, the air flow rate was varied to determine the amount of heat gain. The tabulate data has been drawn by sigma plot software version 10. The results showed that the rate of heat gain in a foam air duct is lower than galvanized iron with insulation and without insulation approximately by 56% and 69%, respectively. In addition, the heat transfer coefficient has a direct proportion with the air flow rate
نمذجة انتقال الحرارة في زعنفة حلقية مع معامل انتقال حرارة متغير
Jan 1, 2012Journal Journal of the Association of Arab Universities for Engineering Studies and Research2012.