Effects of different poses and wind speeds on wind-induced vibration characteristics of a dish solar concentrator system

In order to improve the accuracy of numerical simulation, a new heat transfer model is developed by using a modular approach in the Anstalt für Verbrennungskraftmaschinen (AVL)-Boost software. The improved heat transfer model mainly considers the effects of the swirl and boiling heat transfer inside the engine. In addition, a chemical kinetics mechanism including 475 reactions and 134 species is employed to predict the combustion of diesel engines fueled with biodiesel. The result shows that the boiling heat transfer will occur, especially in the high-temperature area. Analysis shows that the improved model is reliable and its precision is increased. Finally, the perturbation method is employed to investigate the relatively important inputs as the complex nonlinear function with a lot of output data and input data produced by the improved model. The relative effects of different parameters such as EGR, injection mass, injection timing, compression ratio, inlet air pressure, fuel injection pressure, exhaust pressure and inlet air temperature on performance and emission characteristics are compared. The eight parameters are investigated on four outputs of brake power, Brake Specific Fuel Consumption (BSFC), NOx and HC. The injected fuel mass plays an important role in emissions and performance. The EGR, compression ratio and inlet air pressure have a great effect on the HC and NOx emission.

Section: Discussionmentioning

confidence: 99%

Effects of Swirl and Boiling Heat Transfer on the Performance Enhancement and Emission Reduction for a Medium Diesel Engine Fueled with Biodiesel

Tan

Chen

et al. 2021

“…With the increasing energy crisis [46][47][48][49][50] and environmental pollution [51][52][53][54][55][56], the development of a diesel engine is also facing challenges. Nowadays, looking for clean energy and improving the engine to reduce the harm exhaust have become the research focus [57][58][59][60].…”

Section: Discussionmentioning

confidence: 99%

Effects of Different Diesel-Ethanol Dual Fuel Ratio on Performance and Emission Characteristics of Diesel Engine

Zhang

Tian

et al. 2021

In this paper, a four-stroke engine diesel was employed to investigate the effects of different fuel mixture ratios of diesel and ethanol on engine performance and emission characteristics in terms of cylinder temperature, heat release rate, brake power, brake thermal efficiency, brake specific fuel consumption, and cylinder pressure. The corresponding simulation model of diesel engine was developed by AVL-Fire coupled CHEMKIN code, and an improved chemical kinetics mechanism containing 34 reactions and 19 species was employed to simulate the fuel spray process and combustion process. The simulation model was validated by experimental results under 100% and 50% load conditions and used to simulate the combustion process of diesel engine fueled with pure diesel and diesel–ethanol blends with 10%, 20%, and 30% ethanol by volume, respectively. The results showed that the increase of ethanol content in the blended fuel had a certain negative impact on the performance characteristic of diesel engine and significantly improved the emission characteristic of the engine. With the ethanol proportion in the blended fuel increased to 10%, 20%, and 30%, the brake thermal efficiency of the engine increased by 2.24%, 4.33%, and 6.37% respectively. However, the brake-specific fuel consumption increased by 1.56%, 3.49%, and 5.74% and the power decreased by 1.58%, 3.46%, and 5.54% respectively. In addition, with the ethanol proportion in the blended fuel increased to 10%, 20%, and 30%, the carbon monoxide emission decreased by 34.69%, 47.60%, and 56.58%, and the soot emission decreased by 7.83%, 15.24%, and 22.52% respectively. Finally, based on the combining fuzzy and grey correlation theory, nitrogen oxide emission has the highest correlation with engine power and brake-specific fuel consumption. The values reach 0.9103 and 0.8945 respectively. It shows that nitrogen oxide emission and cylinder pressure have a significant relationship on engine power and brake-specific fuel consumption.

“…Nowadays, with the rapid developments of the economy and industrial automation, the shortage of resources (such as non-renewable energy, oil [53], and coal [54]) and environmental pollution (air pollution [55] and human health [56]) are becoming more and more serious [57]. How to effectively control energy shortage [58][59][60][61][62][63] and engine emission reduction [64][65][66][67][68][69][70][71][72][73][74] are the main areas of interest for researchers today. In this paper, an improved model was developed using AVL-BOOST software and employed to investigate the effects of methanol-diesel with different methanol ratios (DM0, DM10, DM20, DM30, and DM40) on engine combustion and emission characteristics at different speeds.…”

Section: Discussionmentioning

confidence: 99%

Effects of Different Mixture Ratios of Methanol-Diesel on the Performance Enhancement and Emission Reduction for a Diesel Engine

Zhang

Tian

et al. 2021

To improve the combustion and emission characteristics of diesel engines, methanol-diesel fuels with different mixing ratios (DM0, DM10, DM20, DM30, and DM40) were used to investigate the effects of methanol addition on the combustion and emission of a four-stroke diesel engine in terms of cylinder pressure, brake power, brake-specific fuel consumption, and nitrogen oxides, soot, and carbon monoxide emissions. Firstly, an improved entire diesel engine model was developed using AVL-BOOST software and validated by the experimental results. The results showed that the increase of methanol content in the fuel mixture had a negative impact on the performance characteristic of the diesel engine, but significantly improved the emission characteristic of the diesel engine. With the methanol ratio in the mixed fuel increased to 10%, 20%, 30%, and 40%, the cylinder pressure of the engine increased by 0.89%, 1.48%, 2.29%, and 3.17%, respectively. However, the power decreased by 3.76%, 6.74%, 11.35%, and 15.45%, the torque decreased by 3.76%, 6.74%, 11.35%, and 15.45%, respectively, and the brake specific fuel consumption increased by 3.77%, 6.92%, 12.33%, and 17.61%, respectively. In addition, with the methanol ratio in the mixed fuel increased to 10%, 20%, 30%, and 40%, the carbon monoxide emission decreased by 21.32%, 39.04%, 49.81%, and 56.59% and the soot emission decreased by 0.25%, 8.69%, 16.81%, and 25.28%, respectively. Therefore, the addition of methanol to the fuel can improve the combustion and emission characteristics of the engine.