Purpose First, this paper aims to explore how CEO humility and relationship conflict in entrepreneurial teams affect the firm-level performance of new ventures. Second, it investigates the moderating effect of CEO political skills on the indirect association between CEO humility and entrepreneurial performance through relationship conflict in entrepreneurial teams. Design/methodology/approach A questionnaire survey was administered to CEOs and their entrepreneurial team members in 171 start-ups in Shanghai, China. The data obtained from the survey were subjected to multiple regression analysis using the SPSS PROCESS macro and confirmatory factor analysis using Mplus. Findings The findings are as follows. First, CEO humility can reduce relationship conflict in entrepreneurial teams. Second, CEO political skills moderate the link between CEO humility and relationship conflict in entrepreneurial teams. The weaker the CEO political skills, the stronger the effect of CEO humility on relationship conflict, and the stronger the CEO political skills, the weaker the effect of CEO humility on relationship conflict. Third, relationship conflict in entrepreneurial teams is negatively related to entrepreneurial performance. Finally, CEO political skills moderate the mediating effect of entrepreneurial team relationship conflict on the CEO humility – entrepreneurial performance link. Practical implications The findings of this study offer guidance for entrepreneurs seeking to improve firm performance. The findings suggest that entrepreneurs should adopt a humble leadership style that cultivates their strengths and minimizes their weaknesses. To improve the centripetal force and cohesion of the entrepreneurial team, they should focus on the team, affirm the contribution of subordinates and accept subordinates’ advice. Originality/value The study reveals that CEO humility has a positive effect on entrepreneurial performance, which enriches research on the effectiveness of humble leadership at the firm level. From the perspective of team relationship conflict, the study also explores the mechanism underlying the effect of CEO humility on entrepreneurial performance, opening the “black box” of CEO humility and entrepreneurial effectiveness. In addition, the study reveals the boundary conditions of the influence of CEO humility, enriching the theoretical literature on humble leadership, political skills and resource conservation.

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Compared to other air compressors, high-speed centrifugal compressors are considered a more suitable choice for a mid-to-high-power fuel cell system due to its high-pressure ratio. As the centrifugal compressor is the most intensive noise source in the fuel cell vehicle, its acoustic characteristics become a major concern in the passenger comfort experience. Unlike the turbocharger compressor, the centrifugal compressor in a fuel cell vehicle tends to operate at near-surge conditions, which leads to flow instabilities and increases the noise level. In this paper, the acoustic characteristics of a centrifugal compressor for a fuel cell vehicle were measured on a compressor test rig covering the full range of the compressor map. The experimental results show that the lowest sound pressure level at the compressor inlet occurs in the design operating area, while the highest level occurs near the mild-surge line. Experimental work was complemented by numerical simulations. Time-averaged flow fields were compared between the near-choke and mild-surge conditions and the detached eddy simulations (DES) were performed at mild-surge conditions. Sparsity-promoting dynamic mode decomposition (SPDMD) was employed as a post-processing method to extract the flow structures associated with corresponding noise features. It was observed that the rotating stall of the impeller inducer is the main cause of the narrow-band whoosh noise near the mild-surge line. The location, number, and speed of the stall cells were identified by SPDMD in rotational and stationary frames.

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The accurate prediction and analysis of electromagnetic excitation source is the pre-condition for the investigation of electromagnetic vibration and noise. In this work, an analytical model for electromagnetic (EM) force calculation of interior permanent magnet synchronous motors (IPMSMs) is proposed by coupling the 2-D model in polar coordinates and the Maxwell stress tensor method (MSTM). In the modeling, the boundary conditions for solving the air-gap magnetic field are firstly simplified based on the equivalent conversion of permanent magnets (PMs). Then, the magnetic field is acquired by solving the governing equation based on the simplified boundary conditions. Finally, the EM force is obtained according to the MSTM. The effectiveness is fully verified by finite element (FE) analysis that the analytical model can be applied not only for the calculation of radial EM force of IPMSMs with/without load but also for the calculation of tangential EM force. Besides, the tangential EM force is further analyzed by 2-D Fourier decomposition, and the relationship between tangential EM force and torque fluctuation is also clarified. The results show that the radial EM force harmonics and the tangential EM force harmonics have the same spatiotemporal characteristics no matter under no-load or load. Moreover, the high-frequency components of tangential EM force harmonics with low spatial orders, which have the highest contribution to vibration and noise, are comparable to those of radial EM force harmonics. Meanwhile, the torque fluctuation of IPMSMs with/without load only comes from the zero-order tangential EM force harmonics in space.