Numerical investigation of the concentric annulus flow around a cylindrical body with contrasted effecting factors

• Published in: Journal of hydrodynamics. Series B 2015-04, Vol.27 (2), p.273-285
• Main Author: 张雪兰 孙西欢 李永业 郗夏楠 郭飞 郑利剑
• Format: Article
• Language: English
• Subjects: concentric annulus; contrasted effecting factors; Engineering; Engineering Fluid Dynamics; hydraulic characteristics; Hydrology/Water Resources; Numerical and Computational Physics; numerical investigation; Simulation; turbulent flow; 圆柱体; 影响因素; 数值模拟; 环形空间; 环流; 管道直径; 速度比; 阻力系数
• ISSN: 1001-6058; 1878-0342
• DOI: 10.1016/S1001-6058(15)60482-6

This paper studies the wall-bounded flow around a cylindrical at a high Reynolds numbers body in a determined computational domain, with simulations of the 3-D, turbulent concentric annulus flow in a straight pipe. Numerical results show that a reversing zone, appearing as a tongue zone with nested velocities higher than the surrounding area, exists behind the cylindrical body. The annulus space is a region of high velocity and low pressure. The zero velocity, of combined the X- velocity and the Y- velocity, exists in the cross sections and no vortex shedding is formed behind the attaching cylinders. Among all investigated effecting factors, the diameters of the attaching and the main cylinders affect the wake feature behind the cylindrical body while the main cylinder length does not affect the distribution tendency of the flow field. The diameters of the main cylinder and the pipe affect the pressure values and the distribution tendencies on the main cylinder surface. Obviously, the increase of the pipe diameter reduces the drag coefficient of the cylindrical body and the increase of the diameter of the main cylinder increases the drag coefficient greatly. The numerical investigation of the concentric annulus flow provides foundations for further improvements of the intricate flow studies.