scholarly journals Knock Control in Shockless Explosion Combustion by Extension of Excitation Time

2018 ◽  
pp. 151-166 ◽  
Author(s):  
Lisa Zander ◽  
Giordana Tornow ◽  
Rupert Klein ◽  
Neda Djordjevic
Keyword(s):  
Excitation Time ◽  
Knock Control

A simulation study of excitation contour of a linear trap with spatial harmonics

2021 ◽  
pp. 146906672110201
Author(s):  
NV Konenkov
Keyword(s):  
Ion Trap ◽  
Theoretical Description ◽  
Resonance Peak ◽  
Linear Ion Trap ◽  
Linear Trap ◽  
Ion Fragmentation ◽  
Excitation Time ◽  
Detailed Simulation ◽  
Trajectory Method ◽  
Ion Cloud

The process of nonlinear resonant excitation of ion oscillations in a linear trap is studied. There is still no detailed simulation of the resonance peak in the literature. We propose to use the excitation contour to describe the collective ion resonance. The excitation contour is a resonant mass peak obtained by the trajectory method with the Gaussian distribution of the initial coordinates and velocities. The following factors are considered: excitation time, low order hexapole and octopole harmonics with amplitudes A3 and A4, the depth of the initial ion cloud position. These multipoles are used for selective ion ejection from linear ion trap. All these factors affect the ion yield and the shape of the contours. Obtained data can be useful for control of such processes as ion fragmentation, ion isolation, ion activation, and ion ejection. Simulated resonance peaks are important for the theoretical description of the ion collective nonlinear resonances.

Optimizing knock thresholds for improved knock control

2013 ◽  
Vol 15 (1) ◽  
pp. 123-132 ◽  
Author(s):  
James C Peyton Jones ◽  
Jill M Spelina ◽  
Jesse Frey
Keyword(s):  
Knock Control

Study On Energy Dissipation Mechanism of an Impact Damper System

2022 ◽  
Author(s):  
Vinayaravi R ◽  
Jayaraj Kochupillai ◽  
Kumaresan D ◽  
Asraff A. K
Keyword(s):  
Energy Dissipation ◽  
Numerical Simulations ◽  
Fundamental Frequency ◽  
Low Frequency ◽  
High Amplitude ◽  
Lagrangian Multiplier ◽  
Impact Damper ◽  
Contact Algorithm ◽  
Dissipation Of Energy ◽  
Excitation Time

Abstract The objective of this paper is to investigate how higher damping is achieved by energy dissipation as high-frequency vibration due to the addition of impact mass. In an impact damper system, collision between primary and impact masses cause an exchange of momentum resulting in dissipation of energy. A numerical model is developed to study the dynamic behaviour of an impact damper system using a MDOF system with Augmented Lagrangian Multiplier contact algorithm. Mathematical modelling and numerical simulations are carried out using ANSYS FEA package. Studies are carried out for various mass ratios subjecting the system to low-frequency high amplitude excitation. Time responses obtained from numerical simulations at fundamental mode when the system is excited in the vicinity of its fundamental frequency are validated by comparing with experimental results. Magnification factor evaluated from numerical simulation results is comparable with those obtained from experimental data. The transient response obtained from numerical simulations is used to study the behaviour of first three modes of the system excited in vicinity of its fundamental frequency. It is inferred that dissipation of energy is a main reason for achieving higher damping for an impact damper system in addition to being transformed to heat, sound, and/or those required to deform a body.

Performance Assessment of Knock Control Systems Subject to Disturbances

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
James Peyton Peyton Jones ◽  
Jesse Frey
Keyword(s):  
Performance Assessment ◽  
Control Systems ◽  
Knock Control

Crosscorrelation migration of microseismic source locations with hybrid imaging condition

Geophysics ◽  
2021 ◽  
pp. 1-49
Author(s):  
Shaojiang Wu ◽  
Yibo Wang ◽  
Fei Xie ◽  
Xu Chang
Keyword(s):  
Cross Correlation ◽  
Hybrid Imaging ◽  
Hydraulic Fractures ◽  
Imaging Condition ◽  
Time Scanning ◽  
Comparison Results ◽  
Excitation Time ◽  
Seismic Location ◽  
Location Methods ◽  
Selection Of

Locating microseismic sources is critical to monitor the hydraulic fractures that occur during fluid extraction/injection in unconventional oil or gas exploration. Waveform-based seismic location methods can reliably and automatically image weak microseismic source locations without phase picking. Among them, the cross-correlation migration (CCM) method can avoid excitation time scanning by generating virtual gathers. We propose a CCM location method based on the hybrid imaging condition (HIC). There are four main steps in the implementation of this method: 1) selection of receivers with good azimuthal coverage; 2) generation of virtual gathers by correlating the reference receiver with the rest of the receivers; 3) summation of back-projections in the virtual gathers; and 4) multiplication of all summations. The CCM-HIC method was tested on synthetic and field datasets, and the results were compared with those obtained by conventional summation imaging condition (SIC) and multiplication imaging condition (MIC). The comparison results demonstrate that the CCM-HIC is sufficiently robust to obtain better stability and higher spatial resolution image of source location, despite the presence of strong noise.

A fuzzy logic map-based knock control for spark ignition engines

2020 ◽  
Vol 280 ◽  
pp. 116036
Author(s):  
Benjamí n Pla ◽  
Pau Bares ◽  
Irina Jiménez ◽  
Carlos Guardiola ◽  
Yahui Zhang ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Knock Control

Remote-Excitation Time-Dependent Surface Catalysis Reaction Using Plasmonic Waveguide on Sites of Single-Crystalline Crossed Nanowires

Plasmonics ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 249-254 ◽  
Author(s):  
Peng Song ◽  
Yuanzuo Li ◽  
Yongqing Li ◽  
Meiyu Zhao ◽  
Liwei Liu ◽  
...  
Keyword(s):  
Plasmonic Waveguide ◽  
Time Dependent ◽  
Single Crystalline ◽  
Surface Catalysis ◽  
Excitation Time

scholarly journals Knock Intensity Distribution and a Stochastic Control Framework for Knock Control

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Mateos Kassa ◽  
Carrie Hall ◽  
Michael Pamminger ◽  
Thomas Wallner
Keyword(s):  
Lognormal Distribution ◽  
Control Strategies ◽  
Fuel Efficiency ◽  
Probabilistic Approach ◽  
Engine Performance ◽  
Operating Conditions ◽  
Control Approach ◽  
Spark Timing ◽  
Almost All ◽  
Knock Control

Abstract One of the main factors limiting the efficiency of spark-ignited (SI) engines is the occurrence of engine knock. In high temperature and high pressure in-cylinder conditions, the fuel–air mixture auto-ignites creating pressure shock waves in the cylinder. Knock can significantly damage the engine and hinder its performance; as such, conservative knock control strategies are generally implemented which avoid such operating conditions at the cost of lower thermal efficiencies. Significant improvements in the performance of conventional knock controllers are possible if the properties of the knock process are better characterized and exploited in knock controller designs. One of the methods undertaken to better characterize knocking instances is to employ a probabilistic approach, in which the likelihood of knock is derived from the statistical distribution of knock intensity (KI). In this paper, it is shown that KI values at a fixed operating point for single fuel and dual fuel engines are accurately described using a mixed lognormal distribution. The fitting accuracy is compared against those for a randomly generated mixed-lognormally distributed dataset, and shown to exceed a 95% accuracy threshold for almost all of the operating points tested. Additionally, this paper discusses a stochastic knock control approach that leverages the mixed lognormal distribution to adjust spark timing based on KI measurements. This more informed knock control strategy would allow for improvements in engine performance and fuel efficiency by minimizing knock occurrences.

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