Design and Experiment Study of High Power Automobile Water Pump Based on CFD

A high power automobile cooling water pump is designed and developed based on the theory of centrifugal pump design and computational fluid dynamics (CFD). The structure of the automobile cooling water pump adopts a curved guide rib structure, so as to avoid the dry friction of the automobile cooling water seal of the pump. The structural elements and flow field of the automobile cooling water pump assembly are optimized by simulation analysis. The peak efficiency of the automobile cooling water pump assembly is more than 51%, the automobile cooling water pump performance has been significantly improved. The effective methods and means of product verification have been developed to ensure the high reliability and durability of the automobile cooling pump assembly

Design and Experiment Study of High Power Automobile Water Pump Based on CFD

A high power automobile cooling water pump is designed and developed based on the theory of centrifugal pump design and computational fluid dynamics (CFD). The structure of the automobile cooling water pump adopts a curved guide rib structure, so as to avoid the dry friction of the automobile cooling water seal of the pump. The structural elements and flow field of the automobile cooling water pump assembly are optimized by simulation analysis. The peak efficiency of the automobile cooling water pump assembly is more than 51%, the automobile cooling water pump performance has been significantly improved. The effective methods and means of product verification have been developed to ensure the high reliability and durability of the automobile cooling pump assembly

The design of underwater tactile force sensor with differential pressure structure and backpropagation neural network calibration

The underwater tactile force measurement was prone to cross-sensitivity, causing the difficulty in distinguishing tactile force signal with the underwater complex environment of water pressure influence. For this problem, an underwater tactile force sensor whose sensing core was based on Microelectromechanical Systems (MEMS) was designed with differential pressure typed structure. The hollow hemispherical flexible contacts located at the upper and lower end, and the hollow cylindrical shell in the middle part composed the structure of the capsule-shaped sensor. The upper flexible contact could sense the compound signal composed of water pressure and tactile force, at the same time, the lower flexible contact could measure the water pressure information. The deformation signal of the upper and lower flexible contacts could be transformed to the force sensor core’s upper and lower surfaces with silicon oil filled in the inner hollow part of the sensor. The tactile force signal could be obtained with water pressure eliminated through vector superposition method under the influence of static pressure of water. The structure and manufacture technology were introduced, and the Backpropagation (BP) neural network data regression algorithm was designed for the cross sensitivity. The experiments are conducted to demonstrate the effectiveness of the differential pressure structure in eliminating the influence of water static pressure. The results indicated that the BP neural network data regression algorithm successfully produced real tactile force signals, which is highly beneficial for the intelligent operation of underwater dexterous hand. Additionally, the sensor has an accuracy of 5%

Spatial distribution and ecological risks of neonicotinoid insecticides for an urban tidal stream of Guangzhou City, South China

Neonicotinoid insecticides (NEOs) are widely used in many urban regions. Studies on NEOs residues in urban tidal streams and the associated ecological risks are limited. In this study, the occurrence, spatiotemporal distribution, and ecological risks of seven selected NEOs in the Wuchong Stream in Guangzhou, China were investigated. Moreover, the correlation between typical urban factors and the ecological risk of NEOs was discussed. In the Wuchong Stream, the concentrations of NEOs in the water samples ranged from 0.97 to 175.92 ng. L-1 in the dry season and 3.15 to 312.92 ng. L-1 in the wet season.The most commonly used neonicotionoids were acetamiprid and imidacloprid in the Wuchong Sream basin. The concentrations of NEOs in the midstream were higher than that in the downstream and upstream. The results of the ecological risk indicated that NEOs were likely to biologically impair the urban stream ecosystem, especially in the dry season. For three typical aquatic organisms, the current concentrations of NEOs posed a significant threat to aquatic insects. Compared to other urban factors, residentidal district and farmland area were the main socioeconomic factors affecting the ecological risk of NEOs in the Wuchong Stream basin. Therefore, the correct and reasonable application of NEOs and continuous improvement of the applicant methods can reduce the environmental risks of urban streams