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In order to predict the thermal fatigue life of the internal combustion engine exhaust manifold effectively, it was necessary to accurately obtain the unsteady heat transfer process between hot streams and exhaust manifold all the time. This paper began with the establishment of unsteady coupled heat transfer model by using serial coupling method of CFD and FEA numerical simulations, then the bidirectional thermal coupling analysis between fluid and structure was realized, as a result, the difficulty that the transient thermal boundary conditions were applied to the solid boundary was solved. What's more, the specific coupling mode, the physical quantities delivery method on the coupling interface and the surface mesh match were studied. On this basis, the differences between strong coupling method and portioned treatment for solving steady thermal stress numerical analysis were compared, and a more convenient and rapid method for solving static thermal stress was found.

The performance of an organic Rankine cycle (ORC) that recovers heat from the exhaust of a heavy-duty diesel engine was simulated. The work was an extension of a prior study that simulated the performance of an experimental ORC system developed and tested at Oak Ridge National laboratory (ORNL). The experimental data were used to set model parameters and validate the results of that simulation. For the current study the model was adapted to consider a 15 liter turbocharged engine versus the original 1.9 liter light-duty automotive turbodiesel studied by ORNL. Exhaust flow rate and temperature data for the heavy-duty engine were obtained from Southwest Research Institute (SwRI) for a range of steady-state engine speeds and loads without EGR. Because of the considerably higher exhaust gas flow rates of the heavy-duty engine, relative to the engine tested by ORNL, a different heat exchanger type was considered in order to keep exhaust pressure drop within practical bounds.

With the rapidly developing automotive industry and stricter environmental protection laws and regulations, lightweight materials, advanced manufacturing processes and structural optimization methods are widely used in body design. Therefore, in order to evaluate and improve the pedestrian protection during a collision, this paper presents an impact simulation modeling and structural optimization method for a sport utility vehicle engine hood made of carbon fiber reinforced plastic (CFRP). Head injury criterion (HIC) was used to evaluate the performance of the hood in this regard. The inner panel and the outer panel of CFRP hood were discretized by shell elements in LS_DYNA. The Mat54-55 card was used to define the mechanical properties of the CFRP hood. In order to reduce the computational costs, just the parts contacted with the hood were modeled. The simulations were done in the prescribed 30 impact points.

The thermal management system is essential for the safe and long-term operation of the power battery. The temperature difference between the individual cells exceeds the acceleration of the battery performance, which leads to battery out of use and affects the performance of the vehicle. Compared with the low heat transfer coefficient of the air-cooling system, the complex structure of the liquid-cooling system and the large quality of phase change material system, the heat pipe has high thermal conductivity, strong isothermal performance and light weight, it’s an efficient cooling element that can be used for thermal management. In this study, the flat plate heat pipe(FPHP) is used to manage the temperature of the battery, through experiments, the optimized placement of the flat heat pipe is obtained.

Magnetorheological fluid (MRF) is used as the transmission medium of the hydraulic retarder. The rheological properties are regulated by changing the magnetic field to achieve accurate control of the retarder's braking torque. Under the action of the external magnetic field, the flow structure and performance of the MRF retarder will be changed in a short time. The apparent viscosity coefficient increases by several orders of magnitude, the fluidity deteriorates and the heat generated by the brake cannot be transferred through the liquid circulation, which will affect the braking torque of the retarder. Changing the surface area of the stator also has an influence on the braking torque of the retarder and the wall heat dissipation. In this study, the relationship between the braking torque of the MRF retarder and the stator surface area of the retarder was analyzed.

In order to avoid the braking recession on heavy commercial vehicles caused by the long-distance continuous braking of the main brake, the hydraulic retarder is widely used as an important brake auxiliary device in various heavy commercial vehicles to improve the vehicle safety. However, the hydraulic retarder not only has the advantages of large braking torque and good stability, but also has the disadvantages of poor retarding ability at low rotating speed, braking lag and difficulty in accurately controlling the braking torque. This paper introduces a new type of hydraulic retarder. The new retarder replaces the oil in the retarder with magnetorheological fluid and applies a magnetic field in the retarder arrangement space, so that slows down the vehicle by using the rheological properties of the magnetorheological fluid under the magnetic field.

Operating level of a metal-belt CVT mainly rest with the ECU. Conventional control strategies which were obtained from tests or PID controller can not correspond to the driver’s intention or provide various driving environments. It is considered that control targets of metal-belt CVT could be distinguished by a speed ratio, line pressure and starting element till now. Running performance of automobile with a CVT mainly depends on the speed ratio control. An adapted fuzzy logic ratio control algorithm is suggested and optimized. A throttle position and its changing rate will be inputs of the FLC to meet the driver’s intention and make the intelligent control come true. A fuzzy logic line pressure control algorithm is also suggested and optimized corresponding to the complicated high line pressure control.

Hydraulic retarder is one of main auxiliary braking devices of the vehicle. When the vehicle is braking, a great pressure from high-speed fluid is received by hydraulic retarder blades. It is difficult to predict rational hydraulic retarder strength, owing to the complexity of the internal flow of oil. An optimal calculation way of hydraulic retarder strength is proposed based on CFD and FEA, concluding a reasonable result. The 3-D model of hydraulic retarder is built in the general CAD software. The model of fluid passage is extracted, according to the condition when the whole flow passage is filled with oil, and imported to CFD software. The inner flow field of hydraulic retarder is analyzed and the hydraulic surface pressure distribution of the hydraulic retarder blade is obtained at the highest rotary speed of turbine wheel.

In this paper a new pressure control method of a modified accumulator-type Electro-hydraulic Braking System (EHB) is proposed. The system is composed of a hydraulic motor pump, an accumulator, an integrated master cylinder, a pedal feel simulator, valves and pipelines. Two pressurizing modes are switched between by-motor and by-accumulator to adapt different pressure boost demands. A differentiator filtering raw sensor signal and calculating pedal speed is designed. By using the pedal feel simulator, the relationship between wheel pressures and brake force is decoupled. The relationships among pedal displacement, pedal force and wheel pressure are calibrated by experiments. A model-based PI controller with predictor is designed to lower the influences caused by delay. Moreover, a self-tuning regulator is introduced to deal with the parameter’s time-varying caused by temperature, brake pads wearing and delay variation.

In this research, the Mg2Si1-xSnx thermoelectric material is used in the exhaust temperature difference power-generating system, and the material's heat transfer characteristic and power-generating characteristic were analyzed. Firstly, steady heat transfer model from vehicle exhaust to cooling water was established. Then the impact of Sn/Si ratio to the thermoelectric characteristic parameter was analyzed. Finally, considering the influence of varying thermal conductivity to the heat transfer process along the material's heat transfer direction, when the cold end temperature of thermoelectric materials was controlled by cooling water respectively boiling at 343K and 373K, the thermoelectric conversion efficiency and power output of Mg2Si1-xSnx thermoelectric materials with different x value were evaluated based on simulation calculation.

This paper combines fluid software STAR-CCM+ and finite element software ABAQUS to solve the temperature field of this Gasoline engine exhaust manifold based on loose coupling method. Through the simulation of car parking cooling - full load condition at full speed, we estimate thermal fatigue life of the exhaust manifold with the plastic strain increment as the evaluation parameters. It can guide the direction of optimal design of the exhaust manifold. Here we also revealed how the bolt force affects the manifold elastic and plastic behavior.

In these years, the advantages of using phase change material (PCM) in the thermal management of electric power battery has been wide spread. Because of the thermal conductivity of most phase change material (eg.wax) is low, many researchers choose to add high conductivity materials (such as black lead). However, the solid-liquid change material has large mass, poor flow-ability and corrosively. Therefore, it still stays on experiential stage. In this paper, the Thermal characteristics of power battery firstly be invested and the requirements of thermal management system also be discussed. Then a new PCM thermal management has been designed which uses pure water as liquid phase change material, adopts PCM with a reflux device for thermal management.

The development of the vehicle quantity and the transportation system accompanies the rise of traffic accidents. Statistics shows that nearly 35-45% traffic accidents are due to drivers’ fatigue. If the driver’s fatigue status could be judged in advance and reminded accurately, the driving safety could be further improved. In this research, the blink frequency and eyes movement information are monitored and the statistical method was used to assess the status of the driving fatigue. The main tasks include locating the edge of the human eyes, obtaining the distance between the upper and lower eyelids for calculating the frequency of the driver's blink. The velocity and position of eyes movement are calculated by detecting the pupils’ movement. The normal eyes movement model is established and the corresponding database is updated constantly by monitoring the driver blink frequency and eyes movement during a certain period of time.

Overloading of trucks can easily cause damage to roads, bridges and other transportation facilities, and accelerate the fatigue loss of the vehicles themselves, and accidents are prone to occur under overload conditions. In recent years, various countries have formulated a series of management methods and governance measures for truck overloading. However, the detection method for overload behavior is not efficient and accurate enough. At present, the method of dynamic load identification is not perfect. No matter whether it is the dynamic weight measurement method of reconstructing the road surface or the non-contact dynamic weight measurement method, little attention is paid to the difference of different vehicles. Especially for different vehicles, there should be different load limits, and the current devices are not smart enough.

This paper introduces two new types of basic components (an Electro-Hydraulic Tube and a Hydraulic Tube) which when connected in an appropriate manner can control flow and pressure for many applications; in addition, one of the devices is readily interfacable to a microprocessor for external control. Some background information about the basic concept and the operation of the two components is introduced. Some of the experimental characteristics will be illustrated and several basic circuit examples will be presented to show how the concept can be implemented. The Electro-Hydraulic Integrated Block (EHIB) and Circuit (EHIC) will be introduced followed by a discussion of the advantages and potential of the EHIC concept.

The development of high precision flow divider/combiner valves has received considerable attention by the authors over the past decade. Several different valve designs for division and combination of flow have been designed which display small flow dividing/combining error (1-2%) when compared to conventional designs (2-10%). Recent studies have improved upon the design in order to reduce cost, weight and complexity of the valve. This paper will present the latest of the authors research into the development of a high precision, autoregulated flow divider/combiner valve with an integral shuttle valve. The autoregulator extends the operating range of the integrated flow divider/combiner valve (for errors less than 2 %) to 10-50 lpm compared to 30-50 lpm for the unregulated valve.

A flow divider valve is a device which allows a single stream of fluid to be split into two paths according to a predetermined ratio and independent of variations or differences in the load pressures. A flow combiner valve combines two paths of fluid into one stream such that the ratio of the flow rates coming into the valve remains independent of any variation or difference between the inlet pressures. This paper describes the design, operation and performance of an integrated flow divider/combiner valve. This design maintains the small flow dividing/combining error of high precision valves (less than 1.5% at rated flow) but incorporates the shuttle valve into the main spool system. This new design reduces the weight of the valve by 20% reducing the cost by approximately 10%. The new structure simplifies the construction of high precision valves and reduces a source of flow dividing/combining error (leakage).

The articulated steering system is widely used in engineering vehicles due to its high mobility and low steering radius. The design parameters have a vital impact on the selection of the steering system assemblies, such as the operation stroke, pressure, and force of the hydraulic cylinders during the steering process, which will affect the system weight. The system energy consumption is also relevant to the geometry parameters. According to the kinetic analysis of the steering system and dynamic analysis of the steering process, the kinetic model of an engineering vehicle steering system is built, and the length and pressure variation of the cylinder is calculated and validated by the field test. The influence of the factors is analyzed based on the established model. To lower the system weight, needed pressure, and force, the multi-objective particle swarm optimization method is initiated to optimize the geometry parameter of the articulated steering system.

In order to make full use of engine exhaust heat, the thermoelectric module been used to contribute to thermoelectric power generation in the automotive. At present, the thermoelectric generators (TEGs) have been developing with continuously advances in thermoelectric technology. And almost all of the existing thermoelectric technologies are adding a gas tank to the vehicle exhaust system which increases the exhaust back pressure and occupying excessive space of the vehicle chassis. In this study, a new TEG integrated with a front silencer muffler (FMTEG) is proposed. The muffler is reshaped as the heat exchanger which has a hexagon cross-section. The water tank and clamping mechanism have been redesigned for the new heat exchanger. The FMTEG system’s dimensions are small that can well meet the installation requirements and has a good compatibility with the vehicle exhaust system.

Recent research has shown that butanol, instead of ethanol, has the potential of introducing a more suitable blend in diesel engines. This is because butanol has properties similar to current transportation fuels in comparison to ethanol. However, the main downside is the high cost of the butanol production process. Acetone-butanol-ethanol (ABE) is an intermediate product of the fermentation process of butanol production. By eliminating the separation and purification processes, using ABE directly in diesel blends has the potential of greatly decreasing the overall cost for fuel production. This could lead to a vast commercial use of ABE-diesel blends on the market. Much research has been done in the past five years concerning spray and combustion processes of both neat ABE and ABE-diesel mixtures. Additionally, different compositions of ABE mixtures had been characterized with a similar experimental approach.