Estimation of Oil Supply Time during Engine Start-Up at Very Low Temperatures

2016 ◽  
Vol 9 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Bogdan R. Kucinschi ◽  
Teng-Hua Shieh
Keyword(s):  
Low Temperatures ◽  
Oil Supply ◽  
Start Up ◽  
Engine Start ◽  
Supply Time

scholarly journals Modelling of nozzle start-up for underexpanded jet generation

2021 ◽  
pp. 1-30
Author(s):  
Maria Alexandrovna Kiryushina ◽  
Tatiana Gennadyevna Elizarova
Keyword(s):  
Low Temperatures ◽  
Complex Geometry ◽  
Main Element ◽  
Pressure Gradients ◽  
Dynamic Algorithm ◽  
Underexpanded Jet ◽  
Open Platform ◽  
High Speeds ◽  
Start Up ◽  
Flow Pressure

A numerical simulation of hydrogen jet in the micronozzle is carried out, which is used as the main element in the experimental installation to study the properties of rarefied gases at high speeds and low temperatures. The features of the transient jet flow - pressure gradients, velocities and the complex geometry of the problem are uniformly described within the framework of the quasi-gas dynamic algorithm included in the open platform OpenFOAM.

Optimization of a Common Rail Diesel Engine Start-up Process

2004 ◽  
Author(s):  
Fuyuan Yang ◽  
Jingyong Zhang ◽  
Qiang Han ◽  
Minggao Ouyang
Keyword(s):  
Diesel Engine ◽  
Common Rail ◽  
Start Up ◽  
Engine Start

Modeling Viscous Isothermal Piston Skirts EHL in Very Low Initial Engine Start Up Speeds

2011 ◽  
Author(s):  
Syed Adnan Qasim ◽  
M. Afzaal Malik
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
High Viscosity ◽  
Solution Technique ◽  
Engine Operation ◽  
Low Speed ◽  
Start Up ◽  
Speed Optimization ◽  
Piston Skirts ◽  
Engine Start

In the normal low-speed engine operation, elastohydrodynamic lubrication (EHL) of piston skirts and lubricant rheology reduce friction and prevent wear. In a few initial start up cycles, a very low engine speed and absence of EHL cause adhesive wear. This study models hydrodynamic and EHL of piston skirts in the initial very low cold engine start up speed by using a high viscosity lubricant. The 2-D Reynolds equation is solved and inverse solution technique is used to calculate the pressures and film thickness profiles in the hydrodynamic and EHL regimes, respectively. The work is extended to investigate the effects of three very low initial engine start up speeds on the transverse eccentricities of piston skirts, film thickness profiles and pressure fields in the hydrodynamic and EHL regimes. Despite using a viscous lubricant, thin EHL film profiles are generated at low start up speeds. This study suggests very low speed optimization in the cold initial engine start up conditions to prevent piston wear under isothermal conditions.

scholarly journals Parametric Investigation of Dual-Mass Flywheel Based on Driveline Start-Up Torsional Vibration Control

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Liupeng He ◽  
Changgao Xia ◽  
Sida Chen ◽  
Jiwei Guo ◽  
Yi Liu
Keyword(s):  
Torsional Vibration ◽  
Torsion Angle ◽  
Torsional Stiffness ◽  
Rotary Inertia ◽  
Research Model ◽  
Attenuation Effect ◽  
Start Up ◽  
Design Requirements ◽  
Simulation Results ◽  
Engine Start

This paper is aimed to investigate the influence of dual-mass flywheel (DMF) kinetic parameters on driveline torsional vibration in engine start-up process, which prescribes the design requirements under start-up condition for DMF matching. On the basis of driveline excitation analysis during engine start-up, the analytical model of DMF driveline torsional vibration system is built and simulated. The vehicle start-up test is conducted and compared with the simulation results. On account of the partial nonstationary characteristic of driveline during start-up, the start-up process is separated into 3 phases for discussing the influence of DMF rotary inertia ratio, hysteresis torque, and nonlinear torsional stiffness on attenuation effect. The test and simulation results show that the DMF undergoes severe oscillation when driveline passes through resonance zone, and the research model is verified to be valid. The DMF design requirements under start-up condition are obtained: the appropriate rotary inertia ratio (the 1st flywheel rotary inertia-to-the 2nd flywheel rotary inertia ratio) is 0.7∼1.1; the interval of DMF small torsion angle should be designed as being with small damping, while large damping is demanded in the interval of large torsion angle; DMF should be equipped with low torsional stiffness when working in start-up process.

Decision Strategy for Fault Troubleshooting Using Bayesian Influence Diagram

2013 ◽  
Vol 385-386 ◽  
pp. 541-545
Author(s):  
Yu Sha Wang ◽  
Ying Ping Huang ◽  
Ren Jie Zhang
Keyword(s):  
Bayesian Network ◽  
Influence Diagram ◽  
Effective Solution ◽  
Decision Strategy ◽  
Fault Probability ◽  
Component Failure ◽  
Start Up ◽  
Faulty Component ◽  
Engine Start

Using Bayesian Network is currently an effective solution to automotive fault diagnosis. However, Bayesian Networks can only be used to reason and calculate probability of component failure. During a fault troubleshooting process, apart from fault probability, diagnostic engineers also need consider the utilities of repair actions to make a sensible repair decision. The paper extends a Bayesian Network to a Bayesian influence diagram, which integrates the influences of both probability and utility. An automobile engine start-up failure is used as a case study to establish troubleshooting decision influence diagram. The diagram combines failure causes, decision actions with their utilities and is able to reason and calculate the expected utilities of each action. Troubleshooters choose faulty component with the highest utility to repair. The method ensures the most sensible repair action is selected in each troubleshooting step.

Particularities of Blading Free Resonance Design for Heavy Duty Gas Turbines With Circumferential Rotor Grooves

2014 ◽  
Author(s):  
Igor Putchkov ◽  
Alexander Arkhipov ◽  
Valery Moskovskikh ◽  
Harald Kissel ◽  
Alexander Laqua
Keyword(s):  
Steady State ◽  
Gas Turbines ◽  
Natural Frequencies ◽  
Contact Spot ◽  
Heavy Duty ◽  
Blade Root ◽  
Lateral Contact ◽  
Start Up ◽  
Blade Frequency ◽  
Engine Start

Blades for heavy duty engines with circumferential rotor grooves are designed such that radial contact is made between the blade teeth and rotor groove at steady state operation conditions. However, sometimes circumferential contact arises between neighboring blade shanks, which is often caused by blade root /rotor thermal expansion. In this case, the radial fixation will give the lower limit of blade frequency band, and the circumferential will give the upper one. The Blade frequency difference between these two fixations might reach about 200–500 Hz depending on blade airfoil and root sizes. When some excitation source (e.g., vane passing frequencies caused by up-stream and down-stream vane counts) has a frequency level situated between blade frequencies caused by radial and circumferential contact, such a case is the subject of the proposed approach. In order to assess how strongly the blade might be fixed under different conditions and how long it might be in resonance during engine start-up and subsequent loading, a 3D elastic-plastic transient analysis and corresponding frequency calculation of blade/rotor assembly is used. At engine start-up the circumferential (lateral) contact between neighboring blade roots is insignificant, and the radial contact between the rotor and the blade is dominant. The lateral contact spot between neighboring blade attachments during start-up appears due to different rates of blade/rotor heating. Further heating leads to an increase of the lateral contact spot areas. The closing of these contact surfaces starts from the outer root edge and spreads toward the inner one, leading to an increase of assembly natural frequencies. Engine loading and further heating lead to the appearance of a circumferential gap between the surfaces, causing the lateral contact to disappear during steady state. The blade root coupling switches again to the usual radial contact state, with the corresponding reduction of natural frequencies. Because the described phenomenon might occur for some time during every start-up and shut-down (from several minutes to couple of hours), it becomes even more severe from a dynamics standpoint if some natural frequency of coupled system crosses the exciting frequency. Examples of assembly frequency tuning are presented.

The Modeling and Simulation of Super-Capacitor in Diesel Engine Starting Process

2012 ◽  
Vol 229-231 ◽  
pp. 1967-1970
Author(s):  
Zhen Min Cui ◽  
Ru Wang
Keyword(s):  
Diesel Engine ◽  
System Modeling ◽  
Super Capacitor ◽  
Power Characteristics ◽  
Modeling Simulation ◽  
Auxiliary Power ◽  
Start Up ◽  
Instantaneous Discharge ◽  
Starting Process ◽  
Engine Start

Diesel engine; Super-capacitor; Starter system; Modeling; Simulation Abstract. In order to improve the start-up performance of the diesel engine and the working conditions of batteries, make efficient use of the high instantaneous discharge power characteristics of the super-capacitor as a diesel engine start-up auxiliary power. Taking the YC6J180 types of Yuchai diesel engine as illustration, diesel engine starting process was modeled and simulated by Matlab/Simulink software, and compared with the simulation model of diesel engine starting system added the super-capacitor. The simulation results show that the diesel engine starter system added the super-capacitor as the auxiliary power, the starting performance is improved significantly, meanwhile improve the battery state, and extend its service life.

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