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In new energy vehicles, the electric motor, as the main power source, is developing toward high power density. However, its heat generation problem always affects the overall performance of the motor, so an efficient motor cooling system is especially important. In desert or water-scarce areas, liquid cooling cannot meet the needs of new energy vehicle motor cooling. When glycol or other liquid coolants are low or depleted, motor heat dissipation becomes less effective. Heat pipe is a heat dissipation technology with advantages such as fast thermal response and light weight. In this paper, by improving the heat pipe arrangement and reducing the overall mass of the heat dissipation system, a heat pipe optimization design based on a drive motor heat dissipation scheme is proposed, and the overall stability of the motor working under high temperature conditions is improved.

With the rapid development of the logistics and transportation industry, heavy-duty trucks play an increasingly important role in social life. However, due to the characteristics of large cargo loads, high center of mass and relatively narrow wheelbase, the driving stability of heavy trucks are poor, and it is easy to cause rollover accidents under high-speed driving conditions, large angle steering and emergency obstacle avoidance. To improve the roll stability of heavy trucks, it is necessary to design an active anti-rollover control system, through the analysis of the yaw rate and the load transfer rate of the vehicle, driving states can be estimated during the driving process. Under the intervention of the control system, the lateral transfer rate of heavy trucks can be reduced to correct the driving posture of the vehicle body and reduce the possibility of rollover accidents.

The turbine blade is a key component in the operation of the steam turbine hence the design and manufacturing level of the blade will directly affect the performance and efficiency of the turbine. CAD/CAM has been the foundation and important part of advanced manufacturing technology. It is important to study the steam turbine blade integrated CAD/CAM system to improve the design and manufacture of the blade. In this paper, the structure of CAD/CAM system for steam turbine blade is studied and the extensible framework structure including user layer, functional layer and system layer is proposed. Based on the control points of the turbine blade profile design method, and based on the expression between the three-dimensional parametric vector modeling method in UG-based platform, the use of UG/Open development tools and Visual C # developed a turbine blade CAD system.

As a traffic deceleration device, speed bumps are widely used to reduce the speed of vehicles and have a good effect. However, in special occasions such as hospital entrance, the bumps caused by ordinary speed bumps are likely to aggravate the pain of patients. In view of this situation, an intelligent speed bump is designed in this paper, which can adjust the height of the speed bump according to the speed of the passing vehicles. When a low-speed vehicle passes by, the elastic link slider module works, so that the upper surface of the speed bump can be elastically lowered to improve the ride comfort of low-speed vehicles. When a high-speed vehicle passes by, the centrifugal locking module will lock the elastic link slider module, and the upper surface of the speed bump will be locked, which plays a role in speed limit. In this paper, SolidWorks and ADAMS/car are used to analyze the process of vehicle passing through the intelligent speed bump.

The ride performance and stability of the vehicle will decrease while the vehicle passing a deceleration bump with relatively high speed. If the speed is too low, the road efficiency and ride comfort will be affected. It is essential to identify the proper speed taking into account all the factors. In this paper, the dynamic model of the vehicle passing through the deceleration bump is established. Three kinds of indicators vibration weighted acceleration RMS, maximum vertical vibration acceleration and wheel load impact coefficient, are used to comprehensively evaluate the ride comfort and safety. The highway model, vehicle model, and common trapezoidal cross-sections bump models are set up in Carsim. Parameters such as vertical acceleration and tire force at different vehicle speeds are obtained. Then use the spline interpolation method to fit the data, and comprehensively consider the three indicators to get the best speed.

The closed cabin temperature is anticipated to be cooled down when it is a bit hot inside the driving car. The traditional air-condition lowers the cabin temperature by frequently switching the status of the compressor, which increases the engine’s parasitic power and shortens the compressor’s service-life. The semiconductor auxiliary cooling system with the properties of no moving parts, high control precision and quick response has the potential to assist the on-board air-condition in modulating the cabin temperature with relative small ranges. Little temperature differences between the cabin and the outside environment means that the system energy consumption to ensure the occupant comfort is relatively low and the inefficiency could be made up by the renewable energy source.

Road traffic congestion sometimes happens at tunnel exit even without high traffic flow. One reason is that the deceleration process is imperceptible when the vehicle is driving to the tunnel exit with gradual upgrade slopes. Nowadays regulations are more concentrated in transport sectors, and control measures are applied to vehicles through the tunnel. This process is careless of vehicles’ specific characteristics and easily distract the driver attention. In this paper, a tunnel climbing acceleration reminder system is introduced. When the speed drop is detected and the analysis show this is due to the driver's unconscious behavior, the system will remind the driver to speed up. Based on the dynamic model and the tunnel properties, the relationship between the throttle opening degrees and the duration with the speed change is studied. Then, the engine braking is considered for the variation of speeds and slopes.

The heavy duty trucks have large engine power and drive continuously in mountainous area, so the heat dissipation of engine is very important. In the traditional cooling system with fixed transmission ratio fan, the cooling capacity is insufficient and the engine is easy to be over-heated when the engine is working in low speed and heavy load conditions. Owning to the bigger size of electric motor compared to the hydraulic motor, it is not suitably applied to the heavy duty trucks. Contrasted with the electric motor, the hydraulic drive cooling system is widely applied in heavy duty trucks due to smaller size, larger power, continuous speed modulation and flexible installation location. However, the low transmission efficiency of the pump-motor system results in high power consumption of the cooling system. In this paper, the mathematical and simulation model of hydraulic-driven fan cooling system is established for the specific engine.

The hydraulic retarder, an important auxiliary brake, has been widely used in heavy vehicles. Under the non-braking working condition, the air resistance torque in the working chamber, which is formed by the rotor of hydraulic retarder's stirring the air, causes pumping loss. This research designs a new type of hydraulic retarder, whose helium is charged into working chamber through closed loop gas system under non-braking working condition, can reduce the parasitic power loss of transmission system. First, under non-braking working condition, the resistance characteristics are analyzed on the base of hydraulic retarder pumping model; then, considering some parameters, such as the volume of chambers and the initial gas pressure, the working chamber gas charge model is established, and the transient gas charge characteristics are also analyzed under non-braking working condition.

In summer, when vehicle parks in direct sunlight, the closed cabin temperature would rise sharply, which affects the occupants step-in-car comfort Solar powered vehicle parking ventilation system adopts the solar energy to drive the original ventilator. Thus, the cabin temperature could be dramatically decreased and the riding comfort could be also improved. This research analyzed the modified crew cabin thermal transfer model. Then the performance of the solar powered ventilation system is analyzed and optimized combined with the power supply characteristics of the photovoltaic element. The storage and reuse of the solar power is achieved on condition that the cabin temperature could be steadily controlled. The research shows that, the internal temperature is mainly affected by the solar radiation intensity and the environment temperature.

The cabin air temperature increases quickly and can reach 80°C when the vehicle parks in the summer sunlight which has the bad influence on the occupants entering comfort. Some luxury vehicles, like Audi A8[1], reduce the internal temperature through operating air-condition in advance or using on-board battery to drive the cabin ventilator, which requires relatively complex control system and limits the system's operating time because of energy consumption. This research adopts the solar wing as the ventilation power supply and accomplishes the cabin real-time heat rejection by achieving the steady air circulation for both inside and outside environment. First, the static thermal transfer model of the crew cabin is established. Then, on the basis of the parameters of the prototype ventilation pipe, the ventilation model for the outside circulation is built.

The hydraulic retarder, which is an auxiliary brake device for enhancing traffic safety, has been widely used in kinds of heavy commercial vehicles. When the vehicle equipped with the retarder is traveling in non-braking state, the transmission loss would be caused because of the stirring air between working wheels of the rotor and the stator no matter if the retarder connects in parallel or in series with the transmission [1]. This paper introduces an elaborate hydraulic retarder air-friction reduction system (AFRS) which consists of a vacuum generating module and pneumatic control module. AFRS works to reduce the air friction by decreasing the gas density between working wheels when the retarder is in non-braking state. The pneumatic control model of hydraulic retarder is built first. Then various driving conditions are considered to verify the performance of the AFRS. The stability of the AFRS is analyzed based on the complete driveline model.