Impact of addition oxy-hydrogen gas (HHO) on vehicle engines performance and emissions

The electrolysis process of water produces oxy-hydrogen (HHO) gas that can be used as an energy source to solve the shortage problem of fossil fuel and reduces the exhaust emissions of greenhouse gases from vehicles engines. In this study, HHO dry cell generator was designed, fabricated and tested experimentally to investigate its performance. The hybrid internal combustion engines using HHO gas is considered one of the most important studied applications. The vehicle engines performance and gas emissions are investigated for two different engines; 150CC with carburetor and 1300CC with Electronic Control Unit (ECU). The results recorded the consumption of the fuel is reduced by 14.8% for 150CC engine and 16.3% for 1300CC engine. HHO gas reduced the emission gases by 33% and 24.5% reduction in CO and 27.4% and 21% reduction in HC for 150CC and 1300CC engines respectively. HHO gas can be efficient used as a secondary fuel for vehicle engines

Double diffusive mixed convection study in a vertical annulus at different aspect ratio and Richardson number

The present study has been considered in heat, mass transfer and the reversal flow occurrence inside the annulus of concentric vertical cylinders numerically. Both the thermal buoyancy and the buoyancy due to different concentrations are of equal magnitude and direction. The forced flow direction effect is investigated. The problem is considered a laminar flow and steady state. The influencing parameters are identified for the problem are Richardson number, Lewis number, and length to gap ratio and Radius ratio. The dimensionless gap is kept constant at unity. The Richardson number is varied from 0.1 to 10, dimensionless length from 5 to 25, the dimensionless radius ratio from 1.5 to 11 and the lewis number from 0.1 to 10. The dimensionless temperature and concentration distributions are illustrated at various range of parameters. In addition, the average values concerning Nusselt as well as Sherwood numbers are correlated. The reverse flow is examined at both aiding and opposing flows. The reverse flow existence is affected by the Richardson number and the length to gap ratio. The value concerning thermal Grashof number is stable at 104. Keywords: Double diffusion, Reverse flow, Vertical cylinder, Annulus ga

The influence of thermal properties of delafossite nanofluid CuAlO2 on the turbulent natural convection inside a cavity

In the present work, an enhancement for the free turbulent convection in a rectangular cavity is examined by using a novel Delafossite Nanofluid. Delafossite CuAlO2 nanoparticles prepared using Al2O3 as dominant at four different weight concentrations of the doping copper 0, 1, 3 and 5% using an easily scalable co- precipitation chemical approach. Al2O3 nanofluid was prepared at three volume concentration 1, 3 and 5%, while the Delafossite CuAl2O3 at 5%. The microstructure of as prepared delafossite CuAlO2 nanoparticles were dedicated by different common methods showed a mean particle size of 28 nm. Thermal properties of water-based nanofluid increased with increasing of a Cu loading level in CuAl2O3. The nanofluid viscosity increases with the augmentation of the nanoparticles and also with increasing the copper content in the delafossite structure. An experimental setup was designed to investigate the influence of the CuAlO2 delafossite nanofluid on both heat transfer and flow structure. A cavity was fabricated with two opposite copper plates. One plate was considered as a heat source subjected to constant heat flux while the other with lower temperature and the rest of sides are considered insulated. The Rayleigh number varied from 7.3 × 107 to 2.21 × 108. The effect of Rayleigh number, volume fraction and the type of nanoparticle were examined experimentally and numerically. The maximum augmentation in the average Nusselt number reaches 51% at Ra = 2.21 × 108 for ϕ = 5% for CuAlO2 for Cu = 5%wt comparing to Al2O3. Keywords: Turbulent, Natural convection, Delafossite nanoflui