scholarly journals Investigation on the Performance Enhancement and Emission Reduction of a Biodiesel Fueled Diesel Engine Based on an Improved Entire Diesel Engine Simulation Model

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 104
Author(s):  
Weigang Yu ◽  
Zhiqing Zhang ◽  
Bo Liu
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Simulation Model ◽  
Combustion Process ◽  
Injection Rate ◽  
Heat Transfer Model ◽  
Injection System ◽  
Biodiesel Fuel ◽  
Transfer Model ◽  
Load Characteristics

In order to improve the efficiency of the diesel engine and reduce emissions, an improved heat transfer model was developed in an AVL-BOOST environment which is a powerful and user-friendly software for engine steady-state and transient performance analysis. The improved heat transfer model considers the advantages of the Woschni1978 heat transfer model and Honhenberg heat transfer model. In addition, a five-component biodiesel skeletal mechanism containing 475 reactions and 134 species was developed to simulate the fuel spray process and combustion process since it contained methyl linolenate, methyl linoleate, methyl oleate, methyl stearate, and methyl palmitate, which are a majority component in most biodiesel. Finally, the propulsion and load characteristics of a diesel engine fueled with biodiesel fuel were investigated by the improved heat transfer model in term of power, brake specific fuel consumption (BSFC), soot and NOx emissions. Similarly, the effects of the fuel injection rate on the diesel engine’s characteristic fueled with biodiesel was studied. The result showed that the errors between experiment and simulation were less than 2%. Thus, the simulation model could predict the propulsion and load characteristics of the diesel engine. The nozzle diameter, injection pressure, and injection advance angle are significant to the injection system. Thus, it is very important to choose the injection rate reasonably.

scholarly journals Effect Analysis on the Performance Enhancement and Emission Reduction of Diesel Engine Fueled with Biodiesel Fuel Based on an Improved Model

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Weigang Yu ◽  
Zhiqing Zhang ◽  
Bo Liu
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Performance Enhancement ◽  
Combustion Process ◽  
Weight Coefficient ◽  
Injection Rate ◽  
Heat Transfer Model ◽  
Biodiesel Fuel ◽  
Transfer Model ◽  
Load Characteristics

To increase the efficiency and accuracy of computing, an improved combined weight coefficient is used to develop an improved heat transfer model in AVL-BOOST environment. Similarly, a five-component biodiesel skeletal mechanism is employed to investigate the combustion process of biodiesel fuel. Then, the AVL-BOOST model is validated by the experimental results under different conditions. Finally, the improved heat transfer model is employed to investigate the propulsion and load characteristics of diesel engine fueled with biodiesel fuel in terms of power, BSFC, soot, and NOx emission. The result shows that the errors between experiment and simulation are less than 2% and the simulation model can predict the propulsion and load characteristics of the diesel engine. In addition, the comprehensive characteristic of case 5 is the best. Moreover, the big inject orifice is not beneficial to the fuel atomization and more soot is produced. Thus, it is very important to choose the appropriate injection rate reasonably.

scholarly journals Effects of Injection Rate Profile on Combustion Process and Emissions in a Diesel Engine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Fuqiang Bai ◽  
Zuowei Zhang ◽  
Yongchen Du ◽  
Fan Zhang ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Combustion Process ◽  
Injection Rate ◽  
Injection System ◽  
Nox Emissions ◽  
Release Process ◽  
Common Rail Injection System ◽  
Soot Emissions ◽  
Rate Profile

When multi-injection is implemented in diesel engine via high pressure common rail injection system, changed interval between injection pulses can induce variation of injection rate profile for sequential injection pulse, though other control parameters are the same. Variations of injection rate shape which influence the air-fuel mixing and combustion process will be important for designing injection strategy. In this research, CFD numerical simulations using KIVA-3V were conducted for examining the effects of injection rate shape on diesel combustion and emissions. After the model was validated by experimental results, five different shapes (including rectangle, slope, triangle, trapezoid, and wedge) of injection rate profiles were investigated. Modeling results demonstrate that injection rate shape can have obvious influence on heat release process and heat release traces which cause different combustion process and emissions. It is observed that the baseline, rectangle (flat), shape of injection rate can have better balance between NOx and soot emissions than the other investigated shapes. As wedge shape brings about the lowest NOx emissions due to retarded heat release, it produces the highest soot emissions among the five shapes. Trapezoid shape has the lowest soot emissions, while its NOx is not the highest one. The highest NOx emissions were produced by triangle shape due to higher peak injection rate.

Computer Assisted Simulation Model for Cryoablation of Prostate Cancer Including the Possible Injury of Rectum

2010 ◽  
Author(s):  
Chih-Wei Chen ◽  
Hong-Sen Kou ◽  
Hsueh-Erh Liu ◽  
Cheng-Keng Chuang ◽  
Li-Jen Wang
Keyword(s):  
Prostate Cancer ◽  
Heat Transfer ◽  
Simulation Model ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Transient Temperature ◽  
Thermal Calculation ◽  
Computer Assisted ◽  
Transfer Model ◽  
Time Duration

This study is to establish a preliminary computer assisted simulation model for cryoablation of a prostate cancer. It is hoped that the results from this study can supply valuable data for the clinician to refer to before a real cryosurgery or cryotherapy. In order to reach the goal of real implementation, a radiologist and an urologist in a medical center in addition to the engineering specialist from the university participated in this interdisciplinary research program. Firstly, hundreds of the two-dimensional medical imaging photos for the patient are obtained from the magnetic resonance imaging (MRI) in the imaging department of hospital. Through the imaging reconstructive software, these photos are trimmed into building a three-dimensional solid modeling. In this step, the urethra, bladder, prostate and rectum are segmented separately into an engineering graphic solid model with high resolution. Secondly, the number of probes, the position of each probe, and the operating time duration of each probe are determined in advance according to the clinical experience from a surgeon. Meanwhile, these data are transferred into the software package of thermal calculation for numerical simulations. Thirdly, the energy equation in the commercial software is modified to behave bio-heat transfer model by the input of user subroutines. Moreover, the occurrence of phase change during some specified temperature range and the latent heat of fusion are also incorporated into bio-heat transfer model to simulate the clinical situation for cryoablation of prostate cancer. In the simulation model, the three-dimensional transient temperature distributions based on cryosurgery for prostate cancer have been demonstrated precisely. The cryoprobes with various freezing time are considered to observe the temperature distribution. In addition, the frozen rectum is displayed in a region enclosed by a critical isotherm of 0°C. The simulated results for cryosurgery of prostate cancer can be supplied for practicing physicians as reference to greatly improve the effectiveness of cryosurgery.

scholarly journals Establishing Boundary Conditions Considering Influence Factors of the Room Equipped with a Ceiling Radiant Cooling Panel

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1684 ◽  
Author(s):  
Sang-Hoon Park ◽  
Dong-Woo Kim ◽  
Goo-Sang Joe ◽  
Seong-Ryong Ryu ◽  
Myoung-Souk Yeo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Simulation Model ◽  
Influence Factors ◽  
Cooling Capacity ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Factors Affecting ◽  
Various Boundary Conditions ◽  
Radiant Cooling

The objective of this study is to establish boundary conditions to evaluate the cooling capacity of the Cooling Radiant Ceiling Panel (CRCP) considering the environment of a room equipped with the CRCP. The current study investigated the boundary conditions and derivation techniques from previous studies. Based on the results of the analysis, a heat transfer model was derived for a room fitted with CRCP. In addition, the heat transfer model was used to derive the factors affecting the cooling capacity of the CRCP and each factor was simulated and verified through this model. The effects of these factors on the capacity of the CRCP was established by using various boundary conditions. To verify the validity of the simulation model, the experimental results were compared with the cooling capacity for a specific case. As a result, it was established that even for the same panel, there was a variance in the cooling capacity of the CRCP based on the boundary conditions and that the influence of the surface exposed to the outdoors had more implications. Consequently, this study presents the influence factors to be considered when designing CRCP.

scholarly journals Investigation into the effect of different fuels on ignition delay of M-type diesel combustion process

2008 ◽  
Vol 12 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Dzevad Bibic ◽  
Ivan Filipovic ◽  
Ales Hribernik ◽  
Boran Pikula
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection System ◽  
Biodiesel Fuel ◽  
Injection Timing ◽  
Injection Angle ◽  
Start Of Injection

An ignition delay is a very complex process which depends on a great number of parameters. In practice, definition of the ignition delay is based on the use of correlation expressions. However, the correlation expressions have very often limited application field. This paper presents a new correlation which has been developed during the research project on the direct injection M-type diesel engine using both the diesel and biodiesel fuel, as well as different values of a static injection timing. A dynamic start of injection, as well as the ignition delay, is defined in two ways. The first approach is based on measurement of a needle lift, while the second is based on measurement of a fuel pressure before the injector. The latter approach requires calculation of pressure signals delay through the fuel injection system and the variation of a static advance injection angle changing. The start of a combustion and the end of the ignition delay is defined on the basis of measurements of an in-cylinder pressure and its point of separation from a skip-fire pressure trace. The developed correlation gives better prediction of the ignition delay definition for the M-type direct injection diesel engine in the case of diesel and biodiesel fuel use when compared with the classic expression by the other authors available in the literature.

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