Currently, most automotive industries use fossil fuels, like diesel fuel, which are harmful for the environment and are known as the main reason for global warming. To reduce the adverse effects of these fuels, scholars have investigated and suggested green fuels like biodiesel. However, further studies should be conducted to improve the functionality of biodiesel fuel in diesel engines. In the current study, three completely distinct biodiesel fuels (namely, B1 with 96 % lauric oil, B2 with 88 % oleic oil, and B3 with 89.5 % ricinoleic oil) were numerically evaluated to carefully investigate the effects of the number of carbon atoms, the OH bond, and viscosity on the performance of a CI engine. First, the predicted in-cylinder pressure, the rate of heat released, and NO emissions were compared to experimental results and an appropriate accord was obtained. For the mentioned biodiesels, the parameters of engine speed, injection angle, piston bowl center depth, and compression ratio were investigated by CFD code under different engine speeds. It was found that changing the piston bowl center depth (PBCD) value from 0.0042 to 0.009 m increased NO and the indicated power by 4% and 3%, respectively, for B1, B2, and B3 biofuels. In addition, when the engine was fueled by Corylus avellana biodiesel, the change in compression ratio from 16 to 24 increased peak pressure and torque by around 77 % and 17 %, respectively. The results showed that the cylinder fueled by high viscosity biodiesel has lower air-fuel mixing. A fuel that has more oxygen atoms in its chemical structure can produce higher NO emissions. Moreover, the injection angle of 150° led to increased fuel consumption rate and indicated power compared to the injection angle of 160°. It was determined that the compression ratio has significant effects on emission and combustion characteristics.

当前，大多数汽车工业使用化石燃料，例如柴油，它们对环境有害，被认为是全球变暖的主要原因。为了减少这些燃料的不利影响，学者们已经研究并提出了绿色燃料，例如生物柴油。但是，应进行进一步的研究以改善柴油发动机中生物柴油的功能。在当前的研究中，对三种完全不同的生物柴油燃料（分别为B1和96％月桂油，B2和88％的油酸以及B3和89.5％的蓖麻油）进行了数值评估，以仔细研究碳原子数的影响， OH键和粘度对CI发动机性能的影响。首先，将预测的缸内压力，释放的热量和NO排放与实验结果进行比较，并获得适当的一致性。对于上述生物柴油，通过CFD代码研究了不同发动机转速下发动机转速，喷射角，活塞碗中心深度和压缩比的参数。发现将B1，B2和B3生物燃料的活塞碗中心深度（PBCD）值从0.0042更改为0.009 m，分别将NO和指示功率分别提高4％和3％。此外，当发动机由榛子生物柴油供油时，压缩比从16变为24时，峰值压力和扭矩分别增加了约77％和17％。结果表明，高粘度生物柴油为气缸提供了较低的空燃比。化学结构中具有更多氧原子的燃料会产生更高的NO排放量。此外，与160°的喷射角相比，150°的喷射角可提高燃油消耗率和指示功率。已确定压缩比对排放和燃烧特性具有显着影响。