摘要 :
Fuel usage negatively impacts the environment and is a significant portion of operational costs of moving freight globally. Reducing fuel consumption is key to lessening environmental impacts and maximizing freight efficiency, the...
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Fuel usage negatively impacts the environment and is a significant portion of operational costs of moving freight globally. Reducing fuel consumption is key to lessening environmental impacts and maximizing freight efficiency, thereby increasing the profit margin of logistic operators. In this paper, fuel economy improvements of a cab-over style 49T heavy duty Foton truck powered by a Cummins 12-liter engine are studied and systematically applied for the China market. Most fuel efficiency improvements are found within the vehicle design when compared to opportunities available at the engine level. Vehicle design (improved aerodynamics), component selection/matching (low rolling resistance tires), and powertrain electronic features integration (shift schedule/electronic trim) offer the largest opportunities for lowering fuel consumption. The powertrain features include Cummins adaptive torque modulation and transmission neutral coasting. 3D CFD (ANSYS Fluent) was used to carry out external truck aerodynamics study, and Cummins Vehicle Mission Simulation (VMS) was used to study and optimize the powertrain integration features. A system simulation model was developed on a baseline truck and calibrated via on-road testing. An energy study quantified the contribution of aerodynamic and rolling resistance losses. Low rolling resistance tires and improved aerodynamic features were applied along with electronic powertrain features to optimize the truck design based on the analysis. The optimized truck demonstrated approximately 20% better fuel economy than the baseline truck in the final testing. Coast-down testing and one-dimensional system simulation indicated that low rolling resistance tires, aerodynamic design, and powertrain integration features contributed 6%, 9%, and 5% of fuel economy improvement, respectively.
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This paper presents a numerical investigation of the performance and internal flow field characteristics of eight mixed flow turbines, which are designed for an automotive turbocharger. The geometric difference between the turbine...
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This paper presents a numerical investigation of the performance and internal flow field characteristics of eight mixed flow turbines, which are designed for an automotive turbocharger. The geometric difference between the turbines is the inlet blade angle, rotor inlet inclined angle, axial chord and number of blades. Commercial CFD software NUMECA, was used to compute the entropy, static pressure, relative velocity and rotor efficiency for each mixed flow turbine at the design condition. The difference in performance and internal flow field characteristics between the eight mixed flow turbines is discussed in detail based on the computational data.
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摘要 :
This paper presents a numerical investigation of the performance and internal flow field characteristics of eight mixed flow turbines, which are designed for an automotive turbocharger. The geometric difference between the turbine...
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This paper presents a numerical investigation of the performance and internal flow field characteristics of eight mixed flow turbines, which are designed for an automotive turbocharger. The geometric difference between the turbines is the inlet blade angle, rotor inlet inclined angle, axial chord and number of blades. Commercial CFD software NUMECA, was used to compute the entropy, static pressure, relative velocity and rotor efficiency for each mixed flow turbine at the design condition. The difference in performance and internal flow field characteristics between the eight mixed flow turbines is discussed in detail based on the computational data.
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In order to suppress the echo signal of target body and translation in Micro-Doppler signal processing, the influence is analyzed based on the feature of echo signal. The method of quadrature reception and translation compensation...
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In order to suppress the echo signal of target body and translation in Micro-Doppler signal processing, the influence is analyzed based on the feature of echo signal. The method of quadrature reception and translation compensation is proposed to suppress the interference of target body echo signal and translation. Theoretical analysis and simulation show that this method can effectively suppress the interference caused by the echo signal of target body and translation.
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摘要 :
In order to suppress the echo signal of target body and translation in Micro-Doppler signal processing, the influence is analyzed based on the feature of echo signal. The method of quadrature reception and translation compensation...
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In order to suppress the echo signal of target body and translation in Micro-Doppler signal processing, the influence is analyzed based on the feature of echo signal. The method of quadrature reception and translation compensation is proposed to suppress the interference of target body echo signal and translation. Theoretical analysis and simulation show that this method can effectively suppress the interference caused by the echo signal of target body and translation.
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Materials transportation is the basis of road and bridge construction, which is an important part of national infrastructure construction. Materials transportation processes of road and bridge projects have some deficiencies in pr...
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Materials transportation is the basis of road and bridge construction, which is an important part of national infrastructure construction. Materials transportation processes of road and bridge projects have some deficiencies in process management, information exchange, status monitoring and process optimization because of its organization and execution features. Aim to improve these deficiencies, a Mobile-Internet-based management platform for materials transportation of road and bridge project is proposed. Firstly, current materials transportation mode and its defects are elaborated and based on the analysis of its complexity and particularity, some detailed requirements for a management platform is presented; Secondly, based on the simplification of materials transportation mode, software structure of a management platform is designed and its main functional modules are designed and elaborated; Finally, this platform is implemented and transportation processes are tested, the result shows that this system can solve problems include nonstandard process, conflicting data source, low efficiency of communication, difficulty of real-time monitoring, data synchronization and data collection.
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In the construction of UHVDC power line in China, the national standard of reradiation interference protecting distance between UHVDC power line and receiving station of AM broadcasting needs to be renewed. In this paper, the wire...
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In the construction of UHVDC power line in China, the national standard of reradiation interference protecting distance between UHVDC power line and receiving station of AM broadcasting needs to be renewed. In this paper, the wire-surface simulation model is used to calculate the interference. In the model, steel tower is represented as surface model, ground wire is represented as wire model, and the whole model is excitated by vertical polarization plane wave. For the deficiency of traditional solution method of protecting distance calculation, a new method is proposed. It is recommended that the whole work frequency band of receiving station should be calculated to determine the space interval which has actual protecting distance. Then the interval is gradually narrowed with dichotomy method until the interval size is within allowable value. With the first-grade receiving station of AM broadcasting as example, the reradiation interference protecting distance from UHVDC power line and station is calculated.
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摘要 :
In the construction of UHVDC power line in China, the national standard of reradiation interference protecting distance between UHVDC power line and receiving station of AM broadcasting needs to be renewed. In this paper, the wire...
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In the construction of UHVDC power line in China, the national standard of reradiation interference protecting distance between UHVDC power line and receiving station of AM broadcasting needs to be renewed. In this paper, the wire-surface simulation model is used to calculate the interference. In the model, steel tower is represented as surface model, ground wire is represented as wire model, and the whole model is excitated by vertical polarization plane wave. For the deficiency of traditional solution method of protecting distance calculation, a new method is proposed. It is recommended that the whole work frequency band of receiving station should be calculated to determine the space interval which has actual protecting distance. Then the interval is gradually narrowed with dichotomy method until the interval size is within allowable value. With the first-grade receiving station of AM broadcasting as example, the reradiation interference protecting distance from UHVDC power line and station is calculated.
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Aiming at the problem of safety accidents that often occur during the assembly process of the inner suspension pole power transmission tower due to the overload of the tower ropes, a sensor for monitoring the force of the inner su...
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Aiming at the problem of safety accidents that often occur during the assembly process of the inner suspension pole power transmission tower due to the overload of the tower ropes, a sensor for monitoring the force of the inner suspension pole group tower ropes is designed. According to the construction characteristics of the inner suspension pole group tower and the force characteristics of the rope, the foil strain gauge and the single-chip STC12LE5616AD are selected to complete the collection and processing of the force data of the tower rope, and the low-power ZigBee technology is used to complete the wireless data transmission. The software system adopts the low power consumption working mode of automatic sleep and timing wake-up to complete the polling transmission of multi-point acquisition data. Determine the shape and structure of the sensor according to the tower rope connection fittings, and use ANSYS simulation calculation to determine that the metal housing of the sensor is made of 42CrMO material.
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摘要 :
Aiming at the problem of safety accidents that often occur during the assembly process of the inner suspension pole power transmission tower due to the overload of the tower ropes, a sensor for monitoring the force of the inner su...
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Aiming at the problem of safety accidents that often occur during the assembly process of the inner suspension pole power transmission tower due to the overload of the tower ropes, a sensor for monitoring the force of the inner suspension pole group tower ropes is designed. According to the construction characteristics of the inner suspension pole group tower and the force characteristics of the rope, the foil strain gauge and the single-chip STC12LE5616AD are selected to complete the collection and processing of the force data of the tower rope, and the low-power ZigBee technology is used to complete the wireless data transmission. The software system adopts the low power consumption working mode of automatic sleep and timing wake-up to complete the polling transmission of multi-point acquisition data. Determine the shape and structure of the sensor according to the tower rope connection fittings, and use ANSYS simulation calculation to determine that the metal housing of the sensor is made of 42CrMO material.
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