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Technical Paper

Investigation on the Deformation of Injector Components and Its Influence on the Injection Process

2020-04-14
2020-01-1398
The deformation of injector components cannot be disregarded as the pressure of the system increases. Deformation directly affects the characteristics of needle movement and injection quantity. In this study, structural deformation of the nozzle, the needle and the control plunger under different pressures is calculated by a simulation model. The value of the deformation of injector components is calculated and the maximum deformation location is also determined. Furthermore, the calculated results indicates that the deformation of the control plunger increases the control chamber volume and the cross-section area between the needle and the needle seat. A MATLAB model is established to The influence of structural deformation on needle movement characteristics and injection quantity is investigate by a numerical model. The results show that the characteristic points of needle movement are delayed and injection quantity increases due to the deformation.
Technical Paper

Response Decoupling Method in Mount Design with Emphasis on Transient Load Conditions

2019-01-18
2018-01-5046
This research examined the focused design, elastic design, energy decoupling, and torque roll axis (TRA) decoupling methods for mount optimization design. Requiring some assumptions, these methods are invalid for some load conditions and constraints. The linearity assumption is advantageous and simplifies both design and optimization analysis, facilitating engineering applications. However, the linearity is rarely seen in real-world applications, and there is no practical method to directly measure the reaction forces in the three locally orthogonal directions, preventing validation of existing methods by experimental results. For nonlinear system identification, there are additional challenges such as unobservable internal variables and the uncertainty of measured data.
Technical Paper

The Application of Solid Selective Catalytic Reduction on Heavy-Duty Diesel Engine

2017-10-08
2017-01-2364
Urea SCR technology is the most promising technique to reduce NOx emissions from heavy duty diesel engines. 32.5wt% aqueous urea solution is widely used as ammonia storage species for the urea SCR process. The thermolysis and hydrolysis of urea produces reducing agent ammonia and reduces NOx emissions to nitrogen and water. However, the application of urea SCR technology has many challenges at low temperature conditions, such as deposits formation in the exhaust pipe, lack deNOx performance at low temperature and freezing below -12°C. For preventing deposits formation, aqueous urea solution is hardly injected into exhaust gas stream at temperature below 200°C. The aqueous urea solution used as reducing agent precursor is the main obstacle for achieving high deNOx performances at low temperature conditions. This paper presents a solid SCR technology for control NOx emissions from heavy duty diesel engines.
Technical Paper

Research on Temperature Stability of an Independent Energy Supply Device with Organic Rankine Cycles Based on Hydraulic Retarder

2017-09-22
2017-01-7003
Hydraulic retarder, as an auxiliary braking device, is widely used in commercial vehicles. Nowadays, the hydraulic retarder’s internal oil is mainly cooled by the coolant circuit directly. It not only aggravates the load of engine cooling system, but also makes the abundant heat energy not be recycled properly. In this study, an independent energy supply device with organic Rankine cycles is applied to solve the problems above. In the structure of this energy supply device, the evaporator’s inlet and outlet is connected in parallel with the oil outlet and inlet of the retarder respectively. A part of oil enters the evaporator to transfer heat with the organic fluid, and the rest of oil enters the oil-water heat exchanger to be cooled by the coolant circuit. According to the different braking conditions of the retarder, the oil temperature in the inlet of the hydraulic retarder can be kept within the proper range through adjusting the oil flow rate into the evaporator properly.
Technical Paper

A Uniform Hardware-in-the-Loop Test Rig for Modular and Integrated Testing of Commercial Vehicle Electronic Braking System

2016-09-27
2016-01-8042
This paper describes a uniform Hardware-In-the-Loop (HiL) test rig for the different types of Electronic Braking System (EBS). It is applied to both modular testing and integrated testing. This test rig includes a vehicle dynamic model, a real-time simulation platform, an actual brake circuit and the EBS system under test. Firstly, the vehicle dynamic model is a highly parameterized commercial vehicle model. So it can simulate different types of commercial vehicle by different parameter configurations. Secondly, multi-types of brake circuit are modeled using brake components simulation library. So, it can test the EBS control unit independently without the influence of any real electro-pneumatic components. And a software EBS controller is also modeled. So it can test the algorithm of EBS offline. Thirdly, all real electro-pneumatic components without real gas inputted are connected to the real-time test platform through independent program-controlled relay-switches.
Technical Paper

Diesel Engine Coordinated Control for AT Upshift Process

2016-09-27
2016-01-8080
The ever-growing number of interacting electronic vehicle control systems requires new control algorithms to manage the increasing system complexity. As a result, torque-based control architecture has been popular for its easy extension as the torque demand variable is the only interface between the engine control algorithms and other vehicle control systems. Under the torque-based control architecture, the engine and AT coordinated control for upshift process is investigated. Based on the dynamics analysis, quantitative relationship between the turbine torque of HTC and output shaft torque of AT has been obtained. Then the coordinated control strategy has been developed to smooth the torque trajectory of AT output shaft. The designed control strategy is tested on a powertrain simulation model in MATLAB/Simulink and a test bench. Through simulation, the shift time range in which the engine coordinated control strategy is effective is acquired.
Technical Paper

Design Approach and Dimensionless Analysis of a Differential Driving Hydraulic Free Piston Engine

2016-09-27
2016-01-8091
A new method for driving the hydraulic free piston engine is proposed. This method achieves the compression stroke automatically rather than special recovery system. Principle of hydraulic differential drive free-piston engine is analyzed and the control strategy of this novel hydraulic driving engine is also introduced. Then energy balance method is used to design the main parameters of the novel engine. High pressure and secondary high pressure of the hydraulic system are constrained by the combustion parameters and therefore parameters are analyzed. In order to verify the effectiveness of energy balance method, the mathematical model is established based on the piston force analysis and engine working principle. The transient results of dynamics are obtained through simulation. In addition, the effectiveness of the simulation is proofed by dimensionless analysis. It indicates that energy balance method realizes the basic performance of hydraulic free piston engine.
Technical Paper

NVH Improvement of Vehicle Powertrain

2012-09-24
2012-01-2007
This paper provides an investigation to improve vehicle powertrain NVH performance via modification of excitation and radiation system of powertrain. First of all, considering different excitation mechanisms of the powertrain, the excitation forces are analyzed. The FEM/BEM coupled analysis and the acoustic transfer vector (ATV) calculation as well as panel contribution analysis are applied to investigating the acoustic characteristics of the powertrain. Then a hybrid approach which couples the transmission gear profile modification for attenuating gear system excitation and the transmission housing modification for reducing transmission housing noise radiation is proposed to improve powertrain NVH performance. Experiment validation is conducted in order to assess the modified results. The assessment shows that this hybrid approach can effectively predict and reduce powertrain noise and vibration.
Technical Paper

EGR and Swirl Distribution Analysis Using Coupled 1D-3D CFD Simulation for a Turbocharged Heavy Duty Diesel Engine

2011-09-13
2011-01-2222
A new diesel engine, called the 6.7L Power Stroke® V-8 Turbo Diesel and code named "Scorpion" was designed and developed by Ford Motor Company for the full-size pickup truck and light commercial vehicle markets. A high pressure Exhaust Gas Recirculation (EGR) layout in combination with a Variable Geometry Turbine (VGT) is used to deliver cooled EGR for in-cylinder NOx reduction. The cylinder-to-cylinder variation of EGR and swirl ratio is tightly controlled by the careful design of the EGR mixer and intake system flow path to reduce variability of cylinder-out PM and NOx emissions. 3D-CFD studies were used to quickly screen several EGR mixer designs based on mixing efficiency and pressure drop considerations. To optimize the intake system, 1D-3D co-simulation methodology with AVL-FIRE and AVL-BOOST has been used to assess the cylinder-to-cylinder EGR distribution and dynamic swirl.
Technical Paper

Rigidity and Strength Analysis and Structure Optimization of one Electric Tractor's Frame Based on FEA

2007-10-30
2007-01-4288
In this paper, the finite element model for static analysis of an electric tractor's frame is presented firstly, and the rigidity and strength of one electric tractor's frame is calculated. Based upon the analysis results, the topology and shape of this electric tractor's frame is optimized. As to the topology optimization, the optimization goal under multiple load cases is defined and the frame is optimized by two steps-one is to determine the position of the transverse rails using solid elements which can simulate the material-filling space, another is to obtain the shape of the frame in which shell elements are applied as to increase the calculation efficiency. After the topology optimization the frame's stiffness is improved significantly but there still is local stress concentration. So the shape of the stress concentration area is optimized using control points method, and the greatest stress is reduced below the strength limits.
Technical Paper

Automotive Electrical System in the New Millennium

1999-11-15
1999-01-3747
The automotive industry is investigating the change of electrical system voltage in a vehicle from the present 14 volt (12V battery) to 42 volt (36V battery) to integrate new electrical and electronic features. These new features require more amperes, thicker wires, large power devices, and eventually higher cost. The existing 14V system is very difficult to sustain so much content because of constraints of performance, efficiency, cost, packaging space, and manufacture-ability. This paper discusses foreseeable needs moving to a higher voltage, and reasons of 42V selection. It explores benefits and drawbacks when the voltage is changed from 14V to 42V in the areas of wire harness, power electronics, smart switching, power supply, etc. Finally, two typical 42/14V dual voltage architectures are presented for a likely 42V transition scenario.
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