Environmental Assessment of a Diesel Engine Fueled with Various Biodiesel Blends: Polynomial Regression and Grey Wolf Optimization

Abstract

A series of tests were carried out to assess the environmental effects of biodiesel blends made of different vegetable oil, such as corn, sunflower, and palm, on exhaust and noise diesel engine emissions. Biodiesel blends with 20% vegetable oil biodiesel and 80% diesel fuel by volume were developed. The tests were conducted in a stationary diesel engine test bed consisting of a single-cylinder, four-stroke, and direct injection engine at variable engine speed. A prediction framework in terms of polynomial regression (PR) was first adopted to determine the correlation between the independent variables (engine speed, fuel type) and the dependent variables (exhaust emissions, noise level, and brake thermal efficiency). After that, a regression model was optimized by the grey wolf optimization (GWO) algorithm to update the current positions of the population in the discrete searching space, resulting in the optimal engine speed and fuel type for lower exhaust and noise emissions and maximizing engine performance. The following conclusions were drawn from the experimental and optimization results: in general, the emissions of unburned hydrocarbon (UHC), carbon dioxide (CO2), and carbon monoxide (CO) from all the different types of biodiesel blends were lower than those of diesel fuel. In contrast, the concentration of nitrogen oxides (NOx) emitted by all the types of biodiesel blends increased. The noise level produced by all the forms of biodiesel, especially palm biodiesel fuel, was lowered when compared to pure diesel. All the tested fuels had a high noise level in the middle frequency band, at 75% engine load, and high engine speeds. On average, the proposed PR-GWO model exhibited remarkable predictive reliability, with a high square of correlation coefficient (R2) of 0.9823 and a low root mean square error (RMSE) of 0.0177. Finally, the proposed model achieved superior outcomes, which may be utilized to predict and maximize engine performance and minimize exhaust and noise emissions.

Assessment of Road Noise Pollution in Urban Residential Areas—A Case Study in Piteşti, Romania

“…Although new vehicles models are becoming quieter, the increasing traffic volume of road traffic increases the noise emitted. Many of the city's central streets have reached traffic saturation, almost daily congested and with slower speeds throughout the day [18][19][20][21][22].…”

“…Of the four possible sources of environmental noise-road traffic, rail traffic, air traffic and industrial activity, the only cause for exceeding limit values in Pitesti may be road traffic, as there is no industry in residential areas, the only railway line is far of residential areas and the airport does not exist [21]. Therefore, as the only source of noise that exceeds the limit levels set by European legislation [2,26] is road traffic, the reduction of ambient noise can only be achieved by reducing road noise, both at the source (emitted noise) and at the receiver (mixed noise-perceived by the inhabitants).…”

Using renewable alternative fuels and studying their impact on the performance and emissions of compression ignition engines

“…Also, most of the researchers in this field agreed that when using biodiesel mixtures, there is a decrease in the braking thermal efficiency compared to normal diesel, and the reason is the characteristics of biodiesel that characterize it. Alahmer et al 21 in their study of a diesel engine with the use of biodiesel mixtures, they confirmed a decrease in the braking thermal efficiency. The reason for the decrease is due to the high viscosity, high density, and low calorific value compared to normal diesel…”

Maximization of CO2 Capture Capacity Using Recent RUNge Kutta Optimizer and Fuzzy Model

“…The purpose of this is to emulate the behavior of specific organisms (particles/agents/solutions) in order to achieve the optimal goal (position/location/target) based on the interaction relationship between these organisms. Formulating the mathematical equations that imitate these relationships frequently results in an optimization method [48].…”