Scholarlink

<p>The motion of hydrophobic objects inside viscous fluids with a complex hydrodynamic behavior plays a major role in reducing the drag force and, consequently, in energy consumption. Herein, the free-falling behavior of spherical hydrophobic and hydrophilic particles inside a static fluid is examined experimentally. The effects of physical parameters, including particle size and diameter, particle density, fluid viscosity, rotational velocity, surface type, and contact angle, were examined on the hydrodynamic behavior of the spherical particles. Spherical particles exhibit varying densities at sizes of 4, 5, and 6&#xa0;mm, and a high-speed camera was used to capture and analyze this phenomenon. To study the effects of fluid viscosity and surface type, two fluids with viscosities of 0.012 and 0.014&#xa0;Pa.s and hydrophilic and hydrophobic surfaces were utilized. The results revealed that the use of the hydrophobic surface increased the terminal velocity and reduced the drag coefficient. Moreover, by increasing the contact angle, the increase in the terminal velocity and the reduction in the drag coefficient are enhanced. However, by increasing the particle diameter, particle density, and rotational velocity, and by reducing fluid viscosity, the terminal velocity was increased; as a result, the duration to reach this terminal velocity was reduced.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Experimental Investigation of Terminal Velocity and Drag Coefficient Reduction for Hydrophobic and Hydrophilic Spherical Particles in a Viscous Fluid

  • 期刊论文

  • 发表日期：

    2026年5月27日

查看全文
  • H. Dehgan,
  • M. H. Nobakhti,
  • E. Esmaeilzadeh,
  • M. Khayat,
  • A. R. Khosroshahi

摘要

The motion of hydrophobic objects inside viscous fluids with a complex hydrodynamic behavior plays a major role in reducing the drag force and, consequently, in energy consumption. Herein, the free-falling behavior of spherical hydrophobic and hydrophilic particles inside a static fluid is examined experimentally. The effects of physical parameters, including particle size and diameter, particle density, fluid viscosity, rotational velocity, surface type, and contact angle, were examined on the hydrodynamic behavior of the spherical particles. Spherical particles exhibit varying densities at sizes of 4, 5, and 6 mm, and a high-speed camera was used to capture and analyze this phenomenon. To study the effects of fluid viscosity and surface type, two fluids with viscosities of 0.012 and 0.014 Pa.s and hydrophilic and hydrophobic surfaces were utilized. The results revealed that the use of the hydrophobic surface increased the terminal velocity and reduced the drag coefficient. Moreover, by increasing the contact angle, the increase in the terminal velocity and the reduction in the drag coefficient are enhanced. However, by increasing the particle diameter, particle density, and rotational velocity, and by reducing fluid viscosity, the terminal velocity was increased; as a result, the duration to reach this terminal velocity was reduced.