Numerical Study of Influencing Factors and the Possibility to Use Vibe Parameters in Crank-Angle Resolved HCCI Control Models

2011 ◽  
Author(s):  
Darko Kozarac ◽  
Momir Sjeric ◽  
Petar Ilincic lng
Keyword(s):  
Influencing Factors ◽  
Numerical Study ◽  
Control Models ◽  
Crank Angle

scholarly journals Study on the Effect of Second Injection Timing on the Engine Performances of a Gasoline/Hydrogen SI Engine with Split Hydrogen Direct Injecting

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5223
Author(s):  
Guanting Li ◽  
Xiumin Yu ◽  
Ping Sun ◽  
Decheng Li
Keyword(s):  
Numerical Study ◽  
Direct Injection ◽  
Mixture Distribution ◽  
Spark Ignition ◽  
Injection Timing ◽  
Si Engine ◽  
Excess Air ◽  
Crank Angle ◽  
Hc Emissions ◽  
Main Factor

Split hydrogen direct injection (SHDI) has been proved capable of better efficiency and fewer emissions. Therefore, to investigate SHDI deeply, a numerical study on the effect of second injection timing was presented at a gasoline/hydrogen spark ignition (SI) engine with SHDI. With an excess air ratio of 1.5, five different second injection timings achieved five kinds of hydrogen mixture distribution (HMD), which was the main factor affecting the engine performances. With SHDI, since the HMD is manageable, the engine can achieve better efficiency and fewer emissions. When the second injection timing was 105° crank angle (CA) before top dead center (BTDC), the Pmax was the highest and the position of the Pmax was the earliest. Compared with the single hydrogen direct injection (HDI), the NOX, CO and HC emissions with SHDI were reduced by 20%, 40% and 72% respectively.

scholarly journals Numerical Investigation of the Characteristics of the In-Cylinder Air Flow in a Compression-Ignition Engine for the Application of Emulsified Biofuels

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1517
Author(s):  
Mohd Fadzli Hamid ◽  
Mohamad Yusof Idroas ◽  
Mazlan Mohamed ◽  
Shukriwani Sa'ad ◽  
Teoh Yew Heng ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Guide Vane ◽  
Engine Performance ◽  
3D Analysis ◽  
Compression Ignition Engine ◽  
Ansys Fluent ◽  
Start Of Injection ◽  
Crank Angle ◽  
Start Of Combustion

This paper presents a numerical analysis of the application of emulsified biofuel (EB) to diesel engines. The study performs a numerical study of three different guide vane designs (GVD) that are incorporated with a shallow depth re-entrance combustion chamber (SCC) piston. The GVD variables were used in three GVD models with different vane heights, that is, 0.2, 0.4 and 0.6 times the radius of the intake runner (R) and these were named 0.20R, 0.40R and 0.60R. The SCC piston and GVD model were designed using SolidWorks 2017, while ANSYS Fluent version 15 was used to perform cold flow engine 3D analysis. The results of the numerical study showed that 0.60R is the optimum guide vane height, as the turbulence kinetic energy (TKE), swirl ratio (Rs), tumble ratio (RT) and cross tumble ratio (RCT) in the fuel injection region improved from the crank angle before the start of injection (SOI) and start of combustion (SOC). This is essential to break up the heavier-fuel molecules of EB so that they mix with the surrounding air, which eventually improves the engine performance.

Numerical and experimental study on knocking combustion in turbocharged direct-injection engines for a wide range of operating conditions

2021 ◽  
pp. 146808742110601
Author(s):  
Magnus Kircher ◽  
Emmeram Meindl ◽  
Christian Hasse
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Numerical Study ◽  
Direct Injection ◽  
Operating Conditions ◽  
Auto Ignition ◽  
Spark Timing ◽  
Crank Angle ◽  
Wide Range ◽  
The Mean

A combined experimental and numerical study is conducted on knocking combustion in turbocharged direct-injection spark-ignition engines. The experimental study is based on parameter variations in the intake-manifold temperature and pressure, as well as the air-fuel equivalence ratio. The transition between knocking and non-knocking operating conditions is studied by conducting a spark timing sweep for each operating parameter. By correlating combustion and global knock quantities, the global knock trends of the mean cycles are identified. Further insight is gained by a detailed analysis based on single cycles. The extensive experimental data is then used as an input to support numerical investigations. Based on 0D knock modeling, the global knock trends are investigated for all operation points. Taking into consideration the influence of nitric oxide on auto-ignition significantly improves the knock model prediction. Additionally, the origin of the observed cyclic variability of knock is investigated. The crank angle at knock onset in 1000 consecutive single cycles is determined using a multi-cycle 0D knock simulation based on detailed single-cycle experimental data. The overall trend is captured well by the simulation, while fluctuations are underpredicted. As one potential reason for the remaining differences of the 0D model predictions local phenomena are investigated. Therefore, 3D CFD simulations of selected operating points are performed to explore local inhomogeneities in the mixture fraction and temperature. The previously developed generalized Knock Integral Method (gKIM), which considers the detailed kinetics and turbulence-chemistry interaction of an ignition progress variable, is improved and applied. The determined influence of spark timing on the mean crank angle at knock onset agrees well with experimental data. In addition, spatially resolved information on the expected position of auto-ignition is analyzed to investigate causes of knocking combustion.

Numerical Study of Distribution Characteristics and Influencing Factors on Geo-Temperature Field of Groundwater Heat Pump

2011 ◽  
Vol 320 ◽  
pp. 536-541 ◽  
Author(s):  
Su Fen Li ◽  
Shi Yao Liu ◽  
Yan Shang ◽  
Guo Fu Du
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Influencing Factors ◽  
Heat Pump ◽  
Numerical Study ◽  
Distribution Characteristics ◽  
Soil Layers ◽  
Groundwater Heat Pump

A 3-D numerical model was developed to simulate the distribution characteristics and influencing factors on geo-temperature field of groundwater heat pump. Analyzing from different soil layers, different permeability, different porosity, different inter-well distances, and different aquifer thickness, temperature distribution characteristics and variations of pumping temperature were gotten. Base on those, permeability and different porosity produce little effect to the temperature of pumping, different inter-well distances and different aquifer thickness produce great effect to the temperature of pumping.

NUMERICAL STUDY ON THE PERFORMANCE IMPROVEMENT OF A ROTARY VANE EXPANDER FOR A CO2 HEAT PUMP CYCLE

2011 ◽  
Vol 19 (04) ◽  
pp. 311-319 ◽  
Author(s):  
HYUN JIN KIM ◽  
WOO YOUNG KIM ◽  
JONG MIN AHN ◽  
SUNG OUG CHO
Keyword(s):  
Numerical Simulation ◽  
Performance Improvement ◽  
Heat Pump ◽  
Numerical Study ◽  
Friction Loss ◽  
Inlet Temperature ◽  
Cylinder Wall ◽  
Operating Pressure ◽  
Expansion Process ◽  
Crank Angle

In order to recover friction loss in the expansion process and increase refrigeration effect in a CO2 heat pump cycle, a rotary vane expander has been designed. Numerical simulation has been carried out to estimate the performance of designed expander, and it has been found that vane jumping or vane recession from the cylinder wall occurs in a certain range of the crank angle. To improve the vane motion, a way of pressurizing the vane back chamber has been employed, and elimination of the vane jumping phenomenon has been confirmed by the numerical simulation. With the operating pressure conditions of 9 MPa/4.5 MPa and inlet temperature of 35°C, the expander efficiency has been calculated to be 42.72%, and improvement of COP of a CO2 heat pump cycle with this expander has been estimated to be about 12.82%.

Numerical study of the low-frequency atomic dynamics in a Lennard-Jones glass

1998 ◽  
Vol 77 (2) ◽  
pp. 473-484 ◽  
Author(s):  
M. Sampoli, P. Benassi, R. Dell'Anna,
Keyword(s):  
Numerical Study ◽  
Low Frequency ◽  
Lennard Jones
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