Simulation of Pressure–Velocity Correlations by Green’s Function Based on Reynolds Stress Model

• Published in: Symmetry (Basel) Vol. 14; no. 7; p. 1352
• Main Authors: Zhang, Jian, Yang, Qingshan, Li, Qiusheng
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-07-2022
• Subjects: cavity flow; Civil engineering; Correlation; elliptic relaxation equation; Energy harvesting; Green's functions; Green’s function; Mathematical models; Methods; Pressure distribution; pressure–velocity correlation; Reynolds stress; Simulation; Temperature effects; Turbulence; Turbulence models; Urban areas; Velocity; Viscosity; Wind power; Wind turbines
• ISSN: 2073-8994; 2073-8994
• DOI: 10.3390/sym14071352

Cost-effective wind energy harvesting by wind turbines in urban areas needs to strengthen the required flow field properties, such as mean velocity, turbulence, and its distribution. This paper conducts a series of CFD simulations to investigate the characteristics and related mechanisms of flow within the cavity, considering the force–turbulence interactions at the RANS scales. The pressure–velocity correlation term is formulated and solved by the elliptic relaxation equation to compensate for the Reynolds stress overestimation. Numerical simulations of flow over an open cavity with the proposed model are compared with corresponding PIV data. The results show that the mean velocity and the fluctuation velocity along the streamwise direction exist a slightly favorable pressure gradient. While the fluctuation velocity and fluctuation pressure show different correlation characteristics along the streamwise direction. Moreover, the pressure–velocity fluctuation correlation becomes obvious near the upper corner of the cavity due to the favorable pressure gradient. Hence, the leading and trailing locations of the cavity are both obvious favorable regions and further emphasis should be put on both high-accurate simulation methods and practical applications.