Investigating wake characteristics for wind turbines situated in complex terrains holds substantial importance for the sustainable advancement of wind energy. In this study, a multiscale simulation framework is established for wake simulations, combining the mesoscale WRF and microscale LES, which incorporates turbulent inflow. The findings reveal that inlet turbulence accelerates the recovery process of the wake, particularly at a distance of 10D downstream from the turbine, where the wake deficit area influenced by inlet turbulence is notably smaller than that affected by the terrain. Moreover, neither inlet turbulence nor terrain conditions alter the wake's mean velocity, but they elevate the turbulence intensity (TI) values in the turbine's near-wake region. Specifically, in the absence of inlet turbulence, the wake turbulence intensity remains at approximately 2% within the 2D to 4D downstream range. The wake TI is significantly higher when inlet turbulence is considered, with a maximum value of 16%. Finally, the power increases by approximately 5.90% with terrain conditions, decreasing by about 13.69% with inlet turbulence. These results indicate that terrain conditions enhance turbine power generation, whereas inlet turbulence significantly reduces it. This high-fidelity numerical framework holds promise as an effective instrument for wind farm siting.
Composite reinforcements are attracting attention in the reinforced concrete (RC) field for their high corrosion resistance, low thermal conductivity, and low electromagnetic interference behavior. However, compared to metallic reinforcements, composites are less ductile and may lead to brittle failure. Three-point flexural tests provide information on the mechanical behavior of metal- and composite-reinforced concrete beams with distinct crack patterns. The structural conditions and failure mechanisms can be defined based on stress change and crack propagation. This study employs finite element analysis (FEA) to simulate the mechanical responses of composite- and metal-reinforced concrete beans under three-point flexural tests and predict the crack propagation in the beams. Machine learning-based algorithms are trained using FEA data to assess the spatial–temporal conditions of the RC beams. The findings indicate that composite rebars provide better reinforcement than metallic rebars in terms of stress fields (30.27% less stress in composite rebars) and crack propagation (fewer cracks in composite RC beams), with the initiation of shear cracks and maximum von Mises stress in rebars being correlated. The findings highlight the effectiveness of the Random Forest Regression (RFR) algorithm (R2=0.96) in assessing RC beam conditions under flexural loads, offering insights for efficient industry applications.
A kind of three-dimensional EFD-BPM scheme and its stability were presented in this paper. And a calculation result of optical field distribution at the fully coupled distance was also given.
The aim of salary system reform is to found a competitively incentive mechanism which conforms to the requirement of socialist market economy and internal law of higher education.This mechanism will stimulate the whole teachers' enthusiasm and creativity in work.The benefit and vigor of school management will also be increased.So,during the reform,carrying out the post performance salary system is an important content to promote the distribution system of universities.The post performance salary system will guarantee the salary based on the related post and the salary changing with post.The workers' salary will be contacted with post responsibility and job performance directly and the workers' enthusiasm of work will be transferred effectively.
Synthetic mechanism of sulfonated aliphatic series superplasticizer was analyzed in this paper, and the synthetic method and performance was summarized. It is suggested that we should pay attention to the research of introduce acid groups to graft and improve aliphatic series condensation compound in future, increase microwave method and pyrogen free method to synthesize aliphatic series superplasticizer, and try to use acetophenone as the material. The effect of water reducing ratio of SAF sulfonated aliphatic series superplasticizer by changing the sequence of feeding material, the type of sulfonating agent and the pH value of solution were contrast in the test.
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