Cylinder

 

cylinder

cylinder

Table of Contents

• 1. introduction
  • 1.1. influence of Reynolds number
  • 1.2. lift and drag coefficient
• 2. numerical modelling of a cylinder
  • 2.1. validation
• 3. ref

1 introduction

drag and lift force change periodically with time

• the contribution of the friction drag to the total drag forces is less than 2-3 %
• if the blockage ratio is less than 6%, then blockage effect is negiable

1.1 influence of Reynolds number

for flow around a circular cylinder

• Re < 40, steady symmetric
• Re > 40, unsteady, asymmetric, alternative vortex shedding

1.2 lift and drag coefficient

• T_v : vortex shedding period
• C_D : drag coefficient
• C_L : lift coefficient

\[ C_D = \frac{F_D}{\frac{1}{2} \rho D U^2} \]

\[ C_L = \frac{F_L}{\frac{1}{2} \rho D U^2} \]

2 numerical modelling of a cylinder

 

2.1 validation

• Parameters for validation: lift/drag coefficient, St number

3 ref

1. flow around circular cylinders, a comprehensive guide through flow phenomena, experiments, applications, mathematical models, and computer

simulations M.M. Zdravkovich oxford Uni. press

Author: kaiming

Created: 2019-05-25 六 04:23

Emacs 25.2.2 (Org mode 8.2.10)

Validate