Al-Qadisiyah Journal for Engineering Sciences

Abstract The current study's objective is to use Diesel-RK simulation software to numerically assess the effects of employing waste plastic oil blends on the thermal characteristics of diesel engines. Each autonomous zone's governing equations are solved using the multi-zone combustion model. Six distinct volumetric mixes were used to analyze the engine's characteristics of waste plastic oil (10%, 20%, 30%, 50%, 70% and 100%) as a comparison to the standard diesel case. The data collected showed a slight decrease in pressure and heat release for all waste plastic oil blends compared to pure diesel fuel. The Sauter mean diameter of droplets increased by 0.91%, 1.85%, 2.68%, 4.35%,5.74% and 7.1% for 10%, 20%,30%, 50%, 70%, and 100\% waste plastic oil (WPO), respectively. The slightly lower cetane number of WPO compared to fossil diesel resulted in a longer ignition delay, resulting in a slightly later combustion start. Brake specific fuel consumption (BSFC) increased by 2.2%, 4.1%, 5.86%, 9.23%, 15.14%, and 15.960% for 10%, 20%,30%, 50%, 70%, and 100% WPO, respectively, because of differences in density, viscosity, and heat content, respectively. A significant drop in the Bosch Smoke Number (BSN) was observed with 30% and 50% WPO, reporting reductions by 2.86% and 4.55%, respectively. The lowest increase in particulate matter was 1.96% and 2.87% for 30% and 50% WPO biodiesel blends. A higher biodiesel content resulted in lower NOx emissions compared to diesel. The findings suggest that 30% WPO is the optimal blend recommended for use in a diesel engine without alteration, which aligns with the results from other studies.

Abstract The work aims to investigate the MHD Casson fluid flow over an exponentially long sheet via a thermally stratified permeable medium. All facets of chemical processes, Joule heating, and exponential heat sources are covered in this subject. By using the appropriate similarity conversions, the leading partial differential equations (PDEs) of the model are transformed into a set of nonlinear ordinary differential equations (ODEs). The description of the previous technique was made simpler by applying the Keller Box methodology. The results reveal that when the viscosity factor is increased, the velocity profile improves, but when the thermal profile improves, the opposite trending impact is evident. The temperature profile exhibits the opposite tendency, despite a decline in the number of observations of the Casson fluid constraint. Joule heating parameters allow for more precise measurements of the heat source's properties by raising the temperature. The concentration graph shows a reduction as the number of observations for the chemical reaction parameter increases. The validity of the problem is investigated by computing the Nusselt number for cumulative Prandtl number observations and comparing the results with the literature.

Abstract This paper proposes a numerical investigation of the behavior of the dual diesel-Liquefied Petroleum Gas (LPG) engine. Numerical analysis is performed with the aid of the simulation program Diesel-RK. Three volumetric LPG blends: 5 % LPG, 8 % LPG, and 10%LPG are inducted with air intake for a single cylinder,4-stroke, constant speed diesel engine with a fixed compression ratio of 15.5/1. No dramatic change in combustion pressure is seen for 5%,8%, and 10% LPG compared to the case of 0% LPG (diesel only). Diesel's maximum energy production is 32.53 (1/deg.) at 365 degrees BTDC, and this is lowered to 30.28 (1/deg.) at the same crank angle when using 10% LPG. Maximum temperature and pressure rise a little bit by 0.14 % and 0.41 % for 10 % LPG. Increasing the LPG injection rate reduces volumetric efficiency and mechanical efficiency slightly. The results found a slight increase in NOx and a considerable reduction is captured in Bosch smoke number (BSN) when LPG is used with diesel. The obtained is validated with the findings of other researchers.

Abstract The depletion rate of conventional petroleum fuels is very fast. Gasoline is used as conventional fuel in the SI engine. Emissions from this fuel cause environmental pollution because it produces harmful emissions for the environment such as CO₂, CO, HC, and NOx. Liquefied petroleum gas (LPG) has physical and chemical properties that make it a favorable fuel for IC engines. It can be used as a fuel alone or combined with gasoline with some minor engine modifications. The engine running on LPG showed improved performance - in terms of fuel economy, overall efficiency compared to petrol. In addition, it is noted that LPG emissions are greatly lower than petrol. This work reviews the research conducted by previous researchers on LPG-powered SI engines under several working conditions.

Abstract This research aims to investigate the literature review on the extraction of algae oil, production of algae methyl ester(AME) biodiesel and the effect of microalgae biodiesel on the performance, combustion and exhaust  emissions of diesel engine. The study dealt with researchers who published their reports between 2006 and 2020. Researches now concentrate on renewable energies, and biodiesel is one of those renewable energy sources. Biodiesel is a fuel similar to diesel and has many positive aspects such as quality, renewable energy, lower exhaust emissions and greater lubricity. In addition to the use of microalgae in the production of fuels, they are used in reducing CO₂ of the atmosphere which in turn results in better air quality to breathe and cleaner environment. Many researchers have paid attention to produce biodiesel derived from microalgae that represents one of the oldest living creatures on the globe. However, by comparing with diesel, it has some drawbacks like lower heat content, higher density, viscosity, and NOx emissions. Optimization strategies is still recommended to fight the side effects of using biodiesel instead of original diesel fuel.

Abstract The aim of the present study is to analyse the combustion characteristics, performance and emission parameters of a variable compression ratio (VCR) diesel engine experimentally and numerically using soybean methyl ester (SME) biodiesel. Initially the engine is fed with diesel to capture the basic data, and then SME was tested as 20 % blend (B20), as 40% blend (B40) and as pure bio-fuel (B100). The experimental investigations are followed by a computational combustion and emissions analysis of diesel engine which is done by using the CFD software (ANSYS FLUENT 13). The combustion, performance and emissions parameters are evaluated by operating the engine at four different compression ratios of 15, 16, 17.5 and 19 and varying the load from 0 kW to 4.4 kW with 1.1 kW step. It is observed that peak pressure is closer to TDC when SME blends is increased. SME blend has earlier combustion start because of the advancement in the injection timing, shorter delay time. Increasing mixing ratio of biodiesel is found to decrease BTE slightly and increases the BSFC. Remarkable decrease in UHC and CO emissions as the ratio of SME is increased due to the complete combustion of biodiesel with presence of more oxygen in the combustion chamber. The measured BSN for B20, B40, and B100 SME was less than that of diesel fuel by 20.44%, 35.78%, and 48.3% respectively. It is inferred from the combustion analysis that as the compression ratio increases from 15 to 19 a decrease in smoke intensity, UHC, and CO, but it increases the emission of NOx. Both turbulent kinetic energy and turbulent dissipation rate were decreased as the percentage of SME increased by 10.84% and 2.01% respectively. The increase in compression ratio from 15 to 19 caused an increase in the peak pressure, density, combustion velocity, turbulence, peak temperature, NOx and a decrease in soot emissions. It can be assessed that the B20 SME is best suited to implement it into diesel engine without any effects. It has been founded from the results that 19 compression ratio has shown good performance and low emissions as compared to other compression ratios. The results obtained from the experimental investigation have been compared with the results of CFD analysis and are found to be in good agreement with each other with just slight deviation.

Abstract This work examines the characteristics of combustion, performance and emissions of single cylinder diesel engine powered by diesel fuel and a different volume percentages of the caster methyl ester (CME). The selected biodiesel is studied numerically using the simulation program diesel-rk. The results reported that peak pressure is closer to the top dead center (TDC), as the percentage of CME. The brake specific fuel consumption (BSFC) is increased slightly as the blending of biodiesel is increased. All the selected biodiesel ratios are found to release higher NOx emission compared to diesel. Dramatic reduction in smoke levels 15.25 %, 35.3 %, 40.7 %, 45.71 %, 49.43 %, and 52.73 % with B10% CME, B20% CME, B30% CME, B50% CME, B70% CME and B100% CME respectively. B20% CME biodiesel was the best remarked ratio which gives slight variations in performance with a good reduction in the carbon emissions compared to diesel fuel. The results are compared with other researchers work and nice convergence is observed.

Abstract The use of gas turbine is increasing day by day for producing electricity and for various industrial applications. In this work a new approach of study for the effect of different cycle arrangements on the performance of simple gas turbine has been investigated. The new cycle arrangements include: reheat with heat exchanger, reheat with water injection, heat exchanger with water injection and reheat together with heat exchanger and water injection. All these arrangements are compared to the performance of gas turbine cycle with no modifications. A Matlab code was written to calculate the combustion characteristics and major performance parameters such as net work, fuel/air ratio, specific fuel consumption, and thermal efficiency ….etc. It’s observed that using reheat in addition to heat exchanger with water injection gives higher thermal efficiency, maximum increment was 28.6% in compare with normal basic cycle and lower fuel consumption, maximum reduction was 22.2 in compare with normal basic cycle.