Particle classification and drag coefficients of irregularly-shaped combustion residues with various size and shape

Impacts of Particle Shape, Skeletal Porosity and Density on the Settling Velocity of Gravel‐Size Coral Debris

“…Another approach to define the drag coefficient of nonspherical particles is to consider their actual projected areas. Especially for flow regimes with $${\mathrm{R}\mathrm{e}}_{p}$$ greater than 100, particles tend to settle with the largest projected area perpendicular to the direction of motion (Bagheri & Bonadonna, 2016; Knoll et al., 2019). Then, the drag coefficient, denoted as $${C}_{d,p}$$, is determined by substituting $${A=A}_{\mathrm{m}\mathrm{p}}=\pi {d}_{p}^{2}/4$$ and $$V=\pi {d}_{n}^{3}/6$$ into Equation 1, as follows: $$${C}_{d,p}=\frac{4(s-1)g{d}_{n}^{3}}{3{w}_{s}^{2}{d}_{p}^{2}}$$$ …”

“…Another approach to define the drag coefficient of nonspherical particles is to consider their actual projected areas. Especially for flow regimes with 𝐴𝐴 Re𝑝𝑝 greater than 100, particles tend to settle with the largest projected area perpendicular to the direction of motion (Bagheri & Bonadonna, 2016;Knoll et al, 2019). Then, the drag coefficient, denoted as 𝐴𝐴 𝐴𝐴𝑑𝑑𝑑𝑑𝑑 , is determined by substituting 1, as follows:…”

On the drag coefficient of flat and non‐flat solid particles of irregular shapes: An experimental validation study

“…To obtain the most accessible range of Re , water as the most commonly used fluid was selected as the liquid medium 19,31–35 . In addition, corn oil was selected as a secondary fluid since its density is less than the density of the particles (1175 kg/m 3 —see Appendix A), also offers good see‐through visibility and weak viscosity‐temperature dependency.…”

“…To obtain the most accessible range of Re, water as the most commonly used fluid was selected as the liquid medium. 19,[31][32][33][34][35] In addition, corn oil was selected as a secondary fluid since its density is less than the density of the particles (1175 kg/m 3 -see Appendix A), also offers good see-through visibility and weak viscosity-temperature dependency. To ensure the stability of rheological properties, all sets of experiments were conducted at atmospheric pressure and room temperatures (20-23 C).…”

“…In order to calculate the drag force, a coefficient of drag ( C D ) should be measured beforehand as a function of solid particle geometry, characteristics of the fluid, and density of the solid particle 6 . A large number of authors investigated the C D of solid particles with regular shapes such as spheres, 7,8 cylinders, 9,10 disks, 11,12 cones, 13 cubes, 12,14 cube octahedron, 6,12 and octahedron and tetrahedron, 6,11 several researchers looked into irregular particles to examine their C D as well experimentally 11,15–18 and numerically 19,20 . A comprehensive list of the correlations proposed to estimate the C D of irregularly shaped particles together with corresponding particles shape factors and the applicable range of Re has been presented in a previous publication by the authors 18 …”