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For high torque-density permanent magnet synchronous in-wheel motor, service life and electromagnetic performance are related directly to winding temperature. The purpose of this paper is to investigate the equivalent stator slot model to calculate the temperature of winding accurately.

This paper analyzes the the law of heat flux transfer in slot, which points the main influence factors of equivalent stator slot model. Thermal network model is used to investigate the drawbacks of conventional equivalent model. Based on the law of heat transfer in stator slot, a new layered winding model is put forward. According to winding type and property of impregnations, detailed method and equivalent principle of the new model are presented. The accuracy of this new method has been verified experimentally.

An accurate equivalent stator slot model should be built according to the low of heat transfer. According to theory analysis, the drawbacks of conventional equivalent stator slot model are pointed: it cannot reflect the temperature gradient of winding; the maximum and the average temperature of winding are much higher than actual value. For the new layered model, equivalent principle is related to winding type and property of impregnations, which makes the new model widely used.

This paper presents a new layered model, and shows detailed method, which is more meaningful for designers. The new layered model takes winding type and property of impregnations into account, which makes the new model widely used. It is verified experimentally that layered model is applicable to not only steady-state temperature field but also transient temperature field.

It is significant to know the real-time indexes about the turbulence flow of the ocean system, which has a deep influence on ocean productivity, distribution of the ocean populations and transmission of the ocean energy, especially the measurement of turbulence flow velocity. So, it is particularly urgent to provide a high-sensitivity, low-cost and reliable fluid flow sensor for industry and consumer product application. This paper aims to design a micro fluid flow sensor with a cross beam membrane structure. The designed sensor can detect the fluid flow velocity and has a low kinetic energy dissipation rate.

In this paper, a micro fluid flow sensor with a cross beam membrane structure is designed to measure the ocean turbulence flow velocity. The design, simulation, fabrication and measurement of the designed sensor are discussed. By testing the simply packaged sensor in the fluid flow and analyzing the experiments data, the results show that the designed sensor has favorable performance.

The paper describes the tests of the designed sensor, and the experimental results show that the designed sensor can measure the fluid flow velocity and has a sensitivity of 11.12 mV/V/(m/s)2 and a low kinetic energy dissipation rate in the range of 10-6-10-4 W/kg.

This paper provides a micro-electro-mechanical systems fluid flow sensor used to measure ocean turbulence flow velocity.

The numerous spoil grounds brought about by mega transportation infrastructure projects which can be influenced by the ecological environment. To achieve better management of spoil grounds, this paper aims to assess their comprehensive risk levels and categorize them into different categories based on ecological environmental risks.

Based on analysis of the environmental characteristics of spoil grounds, this paper first comprehensively identified the ecological environmental risk factors and developed a risk assessment index system to quantitatively describe the comprehensive risk levels. Second, this paper proposed a comprehensive model to determine the risk assessment and categorization of spoil ground group in mega projects integrating improved projection pursuit clustering (PPC) method and K-means clustering algorithm. Finally, a case study of a spoil ground group (includes 50 spoil grounds) in a mega infrastructure project in western China is presented to demonstrate and validate the proposed method.

The results show that our proposed comprehensive model can efficiently assess and categorize the spoil grounds in the group based on their comprehensive ecological environmental risk. In addition, during the process of risk assessment and categorization of spoil grounds, it is necessary to distinguish between sensitive factors and nonsensitive factors. The differences between different categories of spoil grounds can be recognized based on nonsensitive factors, and high-risk spoil grounds which need to be focused more on can be identified according to sensitive factors.

This paper develops a comprehensive model of risk assessment and categorization of a group of spoil grounds based on their ecological environmental risks, which can provide a reference for the management of spoil grounds in mega projects.

This paper aims to improve performance prediction and to acquire more detailed flow structures so as to analyze the turbulence in complex rotor-stator flow.

Hydraulic retarder as typical fluid machinery was numerically investigated by using hybrid Reynolds-averaged Navier–Stokes (RANS)/large eddy simulation (LES) models CIDDES Algebraic Wall-Modeled Large Eddy Simulation (LES) (WMLES) S-Ω and dynamic hybrid RANS/LES (DHRL). The prediction results were compared and analyzed with a RANS model shear stress transport (SST) k-omega which was a recommended choice in engineering.

The numerical results were verified by experiment and indicated that the predicted values for three hybrid turbulence models were more accurate. Then, the transient flow field was further analyzed visually in terms of turbulence statistics, Reynolds number, pressure-streamline, vortex structure and eddy viscosity ratio. The results indicated that HRL approaches could capture unsteady flow phenomena.

This study achieves both in performance prediction improvement and better flow mechanism understanding. The computational fluid dynamics (CFD) could be used instead of flow visualization to a certain extent. The improved CFD method, the fine computational grid and the reasonable simulation settings jointly enhance the application of CFD in the rotor-stator flow.

The improvement was quite encouraging compared with the reported literatures, contributing to the CFD playing a more important role in the flow machinery. DHRL provided the detailed explanation of flow transport between rotor and stator, which was not reported before. Through it, the flow mechanism can be better understood.

The profound impact of the COVID-19 pandemic on the film industry has underscored the growing significance of online movies. However, there is limited research available on the factors that influence the viewership of online films. Therefore, this study aims to use the signaling theory to investigate how signals of varying qualities affect online movie viewership, considering both signal transmission costs and prices.

This study uses a sample of 1,071 online movies released on the iQiyi from July 2020 to July 2022. It uses OLS regression and instrumental variable method to examine the impact of various quality indicators on the viewership of online movies, as well as the moderating effect of price.

After conducting a thorough analysis of this study, it can be deduced that the varying impacts on online movie viewership are attributed to disparities in signal transmission costs. Specifically, star influence and rating exhibit a positive effect on the viewership of online movies, whereas the number of raters has a detrimental impact. Furthermore, there exists an “inverted U-shaped” relationship between the number of reviews and online movie viewership. Additionally, within the consumer decision-making process, both price-cost and price-quality relationships coexist. This is evident as prices negatively affect online movie viewership but positively moderate the relationship between rating, number of reviews and online movie viewership.

The research findings of this study offer valuable insights for online film producers to effectively leverage quality signals and pricing, thereby capturing market attention and enhancing film profitability.