scholarly journals Distortion Optimization of Engine Cylinder Liner Using Spectrum Characterization and Parametric Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Zhaohui Yang ◽  
Baotong Li ◽  
Tianxiang Yu
Keyword(s):  
Spectrum Analysis ◽  
Parametric Analysis ◽  
Cylinder Liner ◽  
Engine Operation ◽  
Practical Procedure ◽  
Operation Conditions ◽  
Powertrain System ◽  
Optimization Simulation ◽  
Structural Configurations ◽  
Critical Components

In an automotive powertrain system, the cylinder liner is one of the most critical components which possesses the intricate structural configurations coupled with complex pattern of various operational loads. This paper attempts to develop a concrete and practical procedure for the optimization of cylinder liner distortion for achieving future requirements regarding exhaust emissions, fuel economy, and oil consumptions. First, numerical calculation based on finite element method (FEM) and computational fluid dynamics (CFD) is performed to capture the mechanism of cylinder liner distortion under actual engine operation conditions. Then, a spectrum analysis approach is developed to describe the distribution characteristic of operational loads (thermal and mechanical) around the circumference of a distorted cylinder bore profile; the FFT procedure provides an efficient way to implement this calculation. With this approach, a relationship between the dominant order of distortion and special operational load is obtained; the design features which are critically relative to cylinder liner distortion are also identified through spectrum analysis. After characterizing the variation tendency of each dominant order of distortion through parametric analysis, a new design scheme is established to implement the distortion optimization. Simulation results indicate that a much better solution is obtained by using the proposed scheme.

scholarly journals Power efficiency estimation based health monitoring and fault detection of modular and reconfigurable robot

2021 ◽  
Author(s):  
Jing Yaun
Keyword(s):  
Fault Detection ◽  
Health Monitoring ◽  
Power Efficiency ◽  
Joint Torque ◽  
Robot System ◽  
Operation Conditions ◽  
Efficiency Estimation ◽  
Joint Torque Sensor ◽  
Reconfigurable Robot ◽  
Critical Components

Power efficiency degradation of machines often provides intrinsic indication of problems associated with their operation conditions. Inspired by this observation, in this thesis work, a simple yet effective power efficiency estimation base health monitoring and fault detection technique is proposed for modular and reconfigurable robot with joint torque sensor. The design of the Ryerson modular and reconfigurable robot system is first introduced, which aims to achieve modularity and compactness of the robot modules. Critical components, such as the joint motor, motor driver, harmonic drive, sensors, and joint brake, have been selected according to the requirement. Power efficiency coefficients of each joint module are obtained using sensor measurements and used directly for health monitoring and fault detection. The proposed method has been experimentally tested on the developed modular and reconfigurable robot with joint torque sensing and a distributed control system. Experimental results have demonstrated the effectiveness of the proposed method.

Estimation of the Occurrence of Micro-Explosion for the Diesel-Biofuel Multi-Components Droplets

2012 ◽  
Author(s):  
Cai Shen ◽  
Chia-fon F. Lee ◽  
Way L. Cheng
Keyword(s):  
Surface Energy ◽  
Minimal Surface ◽  
Weber Number ◽  
Numerical Study ◽  
Engine Operation ◽  
Fuel Droplets ◽  
Fuel Blends ◽  
Operation Conditions ◽  
Simulation Results ◽  
Breakup Model

A numerical study of micro-explosion in multi-component bio-fuel droplets is presented. The onset of micro-explosion is characterized by the normalized onset radius (NOR). Bubble expansion is described by a modified Rayleigh equation. The final breakup is modeled from a surface energy approach by determining the minimal surface energy (MSE). After the breakup, the Sauter mean radius (SMR) for initially small size droplets can be estimated from a look-up table generated from the current breakup model. There exists an optimal droplet size for the onset of micro-explosion. The MSE approach reaches the same conclusion as previous model determining atomization by aerodynamic disturbances. The SMR of secondary droplets can be estimated by the possible void fraction, ε, at breakup and the corresponding surface Weber number, Wes, at the minimal surface energy ratio (MSER). Biodiesel can enhance micro-explosion in the fuel blends of ethanol and diesel (which is represented by a single composition tetradecane). The simulation results show that the secondary atomization of bio-fuel and diesel blends can be achieved by micro-explosion under typical diesel engine operation conditions.

A Study on Cylinder Bore Deformation of a Diesel Engine With Dry Liner Structure

2001 ◽  
Author(s):  
Shigeto Yamamoto ◽  
Hiroshi Sakita ◽  
Masaaki Takiguchi ◽  
Shinichi Sasaki
Keyword(s):  
Thermal Expansion ◽  
Diesel Engine ◽  
Room Temperature ◽  
Engine Speed ◽  
Cylinder Liner ◽  
Cylinder Block ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Actual Operation ◽  
Cylinder Bore

Abstract The deformation of the cylinder liner of a diesel engine in actual operation have been measured by the means of a rotary piston, and the deformation has been compared with those measured statically at room temperature. As a result, it is found that the deformation of the liner in engine operation is hardly affected by the deformation at room temperature, but it follows the deformation of the cylinder block where the liner is inserted. It is also found as follows: The deformation of the liner upper portion varies according to the head bolts and the engine load, while the effect of the cylinder pressure is insignificant. The deformation at the middle of the liner changes mainly by the thermal expansion in the thrust direction, while the deformation at the lower portion is not affected by the engine speed or the load.

scholarly journals Spectrum Analysis and Optimization of the Axial Magnetic Gear with Halbach Permanent Magnet Arrays

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2003
Author(s):  
Fang Hu ◽  
Yilan Zhou ◽  
Hesong Cui ◽  
Xiao Liu
Keyword(s):  
Permanent Magnet ◽  
Axial Force ◽  
Spectrum Analysis ◽  
Parametric Analysis ◽  
Air Gap ◽  
Torque Density ◽  
Output Torque ◽  
Magnetic Gear ◽  
The Difference ◽  
Force Calculation

In order to study the contribution of each harmonic to the output torque and axial torque of the axial magnetic gear with Halbach permanent magnet arrays (HAMG), torque and axial force calculation formulas of the HAMG are proposed based on the air-gap flux density distribution of the HAMG. Because of the difference of the air-gap flux densities at different radii, two simplified torque and axial force calculation formulas are proposed and compared. To improve the torque capability of the HAMG, parametric analysis of eight dimensional parameters is firstly conducted. By parametric analysis, six parameters such as the inner radius have been found to have obvious impact on the output torque and output torque density of the HAMG. The optimization using Maxwell software is then executed for maximizing the output torque density of the HAMG. The output torque density of the optimized HAMG is improved from 78.1 kNm/m3 to 93.3 kNm/m3 with an increase of 19%. Furthermore, spectrum analysis is also presented to illustrate the significant output torque improvement based on the torque calculation formulas.

Engine Performance and Emissions Formation for RME and Conventional Diesel Oil: A Comparative Study

2009 ◽  
Author(s):  
Junfeng Yang ◽  
Monica Johansson ◽  
Valeri Golovitchev
Keyword(s):  
Diesel Engine ◽  
Comparative Study ◽  
Soot Formation ◽  
Engine Performance ◽  
Oxidation Mechanism ◽  
Diesel Oil ◽  
Engine Operation ◽  
Operation Conditions ◽  
Performance And Emissions ◽  
Engine Performance And Emissions

A comparative study on engine performance and emissions (NOx, soot) formation has been carried out for the Volvo D12C diesel engine fueled by Rapeseed Methyl Ester, RME and conventional diesel oil. The combustion models, used in this paper, are the modifications of those described in [1–2]. After the compilation of liquid properties of RME specified as methyl oleate, C19H36O2, making up 60% of RME. The oxidation mechanism has been compiled based on methyl butanoate ester, mb, C5H10O2 oxidation model [3] supplemented by the sub-mechanisms for two proposed fuel constituent components, methyl decanoate, md, C11H22O2, n-heptane, C7H16, and soot and NOx formations reduced and “tuned” by using the sensitivity analysis. A special global reaction was introduced to “crack” the main fuel into constituent components, md, mb and propyne, C3H4, to reproduce accurately the proposed RME chemical formula. The sub-mechanisms were collected in the general one consisting of 99 species participating in 411 reactions. The combustion mechanism was validated using shock-tube ignition-delay data at diesel engine conditions and flame propagation speeds at atmospheric conditions. The engine simulations were carried out for Volvo D12C engine fueled both RME and conventional diesel oil. The numerical results illustrate that in the case of RME, nearly 100% combustion efficiency was predicted when the cumulative heat release, was compared with the RME LHV, 37.2 kJ/g.. To minimize NOx emissions, the effects of 20–30% EGR levels depending on the engine loads and different injection strategies were analyses. To confirm the optimal engine operation conditions, a special technique based on the time-transient parametric φ-T maps [4] has been used.

Optimization of TWC Design for Various Engine Operation Conditions

2019 ◽  
Author(s):  
Yuki Toya ◽  
Hiroki Nakayama ◽  
Hiroyuki Hara ◽  
Makoto Nagata
Keyword(s):  
Engine Operation ◽  
Operation Conditions
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