To improve the performance of gas-burning Engines, hydrogen fuel was added to the Engine intake mixture as a supplement, along with natural gas, due to its higher calorific value, wider ignition range, higher flame speed, faster combustion, and lower combustion temperature. A gas-burning Engine from the light-duty category was chosen as the base Engine. The Engine simulation process was done in GT-Power software and validation was done using the performance test results of the base Engine with gas fuel. Different percentages of the combination of natural gas and hydrogen fuels were applied to the simulation model by applying different combustion monitoring conditions and while checking Engine performance indicators such as torque, BSFC, volumetric efficiency, BMEP, in-cylinder pressure, and NOx emission, the best percentages for the fuel mixture is designated. The results show that adding hydrogen fuel to natural gas improves the performance characteristics of the Engine. Based on the obtained results, with hydrogen percentages equal to 10% to 20% in combination with gas, the performance indicators are improved, and for hydrogen amounts greater than 30% in the fuel composition, there will be no significant effect on improving Engine behavior.

The effects of using butanol– gasoline-blended fuels on performance, fuel consumption, and emission characteristics of a four-cylinder spark-ignition Engine were experimentally investigated. The butanol-blending fraction was varied from 10 to 50% by volume. The Engine speeds were tested at 2250 and 4250 rpm, while the throttle positions were set at 30% and 70%. The Engine performance, specific fuel consumption, and emission properties have been carried out and compared. The results show that, at high throttle position, the flame propagation speed of combustion process as using the butanol– gasoline blends decreases as increasing the butanol-blending fraction and this becomes more obvious with the increase of Engine speed. The Engine brake torque and power are improved, as the butanol-blending fraction is less than 30% at low open throttle position, while those are gradually decayed as increasing throttle opening level. A significant reduction is observed in specific fuel consumption, as the butanol-blending fraction is less than 30% for all the tests. The emissions of CO, HC, and CO2 in the case of using butanol– gasoline blends are much better than those in the case of using pure gasoline. However, NOx emission is worse than that of the pure gasoline for all the test blends.

Using ethanol in gasoline is considered one of the most significant goals in the 2030 agenda, which has been set a 15-year plan in order to achieve it since 2015. Appropriately, this project was planned for predicting the value of the most important Engine parameters such as the equivalence air-fuel ratio (φ), fuel consumption (ṁf), and brake thermal efficiency nb. th, and brake-specific fuel consumption (BSFC) by regression models. According to the protocol of this project, first, the determined percentages of ethanol were added (0, 20, 40, 60, and 80%) to gasoline at different Engine speeds (850, 1000, 2000, 3000, and 4000 rpm and the New European Driving Cycle test). After testing, calculating, mathematical programming, and fitting the regression models for the two SI-Engine (TU5 and EF7) with different properties of Engine design,12 regression equations have been determined for each of the ‘ (positive linear model), (ṁf) (negative linear model), nb.th (negative second-order polynomial model), and BSFC (positive second-order polynomial model), respectively. Clearly, these 48 regression equations with different line slopes will be able to predict the exact value of the ‘, (ṁf), nb.th, and BSFC for each concentration of ethanol at different Engine speeds in order to help automotive industries for trend predicting them in other similar Engines.

Strict emission regulations together with reducing fossil fuels resources lead to more attention on new combustion strategies and alternative fuels such as biodiesel which is renewable, environmentally friendly and more cost-effective than other fuels. In this study, CONVERGE CFD software coupling with chemical kinetics mechanism is used to numerically investigation of natural gas (NG)/biodiesel dual fuel Engine. The discussed biodiesel consists of 25% methyl decanoate (MD), 25% methyl-9-decanoate (MD9D) and 50% diesel. A comparative study of NG/diesel and NG/biodiesel fueled cases is performed to highlight the combustion characteristics of biodiesel. For all simulated cases, it is supposed that 5% of energy is supplied by high reactive fuel (i.e., Diesel or Biodiesel) and 95% is coming with low reactive fuel (i.e., Natural Gas). Results revealed that in full load condition, using biodiesel/NG led to 86% lower carbon monoxide (CO) and 91% unburned hydrocarbons (UHC). On the other hand, peak pressure and maximum in-cylinder temperature increased 5% and 83 K, respectively which led to 0.6% efficiency improvement. according to the results of different injection timing, when it was advanced from -4 to -20 crank angle degree after top dead center (CAD ATDC) for biodiesel/NG and diesel/NG, the indicated mean effective pressure (IMEP) and gross thermal efficiency (GTE) reached at their peaks 18.3 bar and 48.2% at -12 CAD ATDC, 18.05 bar and 47.7% at -8 CAD ATDC respectively.

Sound is one of the forms of mechanical energy and the two main characteristics of sound are intensity or power and frequency or wavelength of sound.their performance against the incoming sound wave, industrial silencers can be divided into two general groups of resonating and absorption silencers, the main difference between these silencers is the release of sound energy from the channeling system, which is one of the common examples of the use of resonating type silencers, their use in It is the internal combustion Engines that distinguish absorption silencers from the resonator type based on the fact that the main and visible part of the act of muting the sound is achieved by changing sound energy to heat energy.The goal of this article is to design a muffler based on the breaking of sound frequencies resulting from the movement of fluid in the exhaust output of vehicles, which leads to a reduction of at least 50 db of sound and gives the operator enough peace and concentration. In this article, after examining three types of mufflers, absorbent mufflers that use the properties of porous absorbent material to absorb passing sound and are the simplest form of mufflers, have been selected, analyzed and reviewed and are suitable for the OM457 Engine of Idem Industrial Company. It designed for maximum inlet exhaust temperature is 520 and for the maximum kW power is 315 with the maximum discharge relative pressure of 185 mbar for homogenization with the standard atmosphere.

Improving participation in voluntary activities in Iran is important because increasing productivity among young people, given the country's young population, contributes to community sustainability. Therefore, a better understanding of volunteer motivation in Iranian youth is needed. The Volunteer Functions Inventory (VFI) for assessing volunteer motivations has good psychometric properties and is adapted to several languages, but no validated Iranian translation yet exists. The purpose of this study was to investigate the psychometric characteristics of voluntary functions inventory in members of Iranian Red Crescent Society. Sample size was 595 members of Youth Organization of Iranian Red Crescent Society from 31 provinces and 175 cities of Iran that were selected by multi-stage cluster sampling method and responded to voluntary functions inventory. Data were collected using a demographic sample and voluntary functions inventory (VFI). Confirmatory factor analysis using principal components method was used for data analysis. The results of the present study showed that the voluntary functions inventory had validity and reliability. Also, the factor structure showed that 29 items and 6 factors well assess people's attitudes to volunteering, and the structure of this inventory was well-fitted and confirmed all goodness of fit models. The present study provides the use of the Iranian translation of the Voluntary Functions Inventory (6 scales and 29 items) to assess volunteer motivation among young Iranian volunteers.

The intake port of a CA4DD diesel Engine was investigated by a computational fluid dynamics (CFD) numerical simulation to enhance the intake swirl and improve the flow characteristics in the Engine. The uniform design method was applied to study the influence of guide vanes with different parameters on the intake process at various valve lifts. Nine guide vane models were established and compared to the base model using CATIA™ 3D CAD software. Numerical simulations were conduct with Xflow software based on the lattice Boltzmann method (LBM). The distributions of the streamlines, vorticity, velocity and turbulent intensity in each cylinder were simulated and analyzed. The results show that the influence of the guide vanes on the swirl ratio was greater than 37%, and the flow coefficient was less than 5% compared to the base model. Scheme 5, H7. 5-L50-θ20 (guide vane height of 7. 5 mm, length of 50 mm and angle of 20°), provided good performance. The flow characteristics of the optimal guide vane model were verified through a steady flow test. When the guide vane aspect ratio and angle were within the ranges of 3. 5-6. 9 and 12. 2°-20. 2°, respectively, the swirl ratio had the best effect at maximum valve lift. This study provides a theoretical basis for improving the performance of dual-intake diesel Engines.

Fuel reactivity controlled compression ignition (RCCI) Engines are promising approaches to achieve high efficiency and clean combustion. Using biogas as a primary fuel in the Engines causes better control of the combustion process due to its reactivity gradient with diesel fuel. In this study, biogas is inducted into the Engine through an inlet port, and diesel as a high reactivity fuel is injected into the Engine. At a constant Engine speed of 1300 rpm and a fixed amount of diesel mass, a broad range of indicated mean effective pressure from 5.6 to 13.5 is studied. Also, the effects of different compositions of biogas and biogas to diesel ratio on combustion characteristics and emission levels are studied. Results show that changes in the amount of CO2 in biogas composition lead to drastic changes in maximum pressure, temperature, and emission levels. In other words, increasing the amount of CO2 in biogas and also the ratio of biogas to diesel both significantly decrease maximum pressure, temperature, and NOx emission.

The main objective of this research is to study the effects of JP-4-biodiesel-diesel fuel blends and operating parameters on the emission characteristics of a CI Engine. The experimental tests were performed on a four-cylinder DI diesel Engine. The Mixture-RSM method was used to develop mathematical models based on experimental data. The results showed that with the increase of the biodiesel proportion in the fuel blend, the emission of hydrocarbon and carbon monoxide in the exhaust decreases due to oxygen contents in the molecular structure of biodiesel that leads to effective combustion. According to the results, HC and CO emissions boosted up significantly with the use of jet fuel JP-4 in fuel mixture due to the lower cetane index of jet fuel in comparison with diesel and biodiesel. Results also indicated that the NOx formation is highly related to biodiesel proportion in fuel mixture due to less compressibility and its higher cetane number. On the other hand, the results indicated that NOx emissions reduced by using JP-4 as a result of retarded combustion of jet fuel that reduces combustion temperature. According to the results, CO and HC emission decreased at higher Engine loads due to a more complete combustion condition. However, the NOx emission continuously intensifies at the higher levels of Engine load due to the arising temperature of combustion gas. Generally, the results indicated that the use of JP4 fuel can improve NOx emissions of the Engine but it does not have a desirable effect on other emission characteristics of the Engine.