Flow over a cylinder Flow Simulation using SolidWorks
AIM:
In this project we Simulate the flow over a cylinder and then calculate the Reynolds number. Then increase the Reynolds number by a factor of 20%, 40%, and 100% then run the transient flow simulation.we Create animations for pressure-velocity for all the three Reynolds number.
INTRODUCTION:
1.Reynolds number
Reynolds number is a dimensionless value which is applied in fluid mechanics to represent whether the fluid flow in a duct or pat a body is steady or turbulent. This value is obtained by comparing the inertial force with the viscous force.
The Reynolds number id denoted by Re.
Reynolds number is given by,
Reynolds Number = Inertial Force / Viscous Force
The Reynolds number formula is expressed by,
Where,
ρ = density of the fluid,
V = velocity of the fluid,
μ = viscosity of fluid,
L = length or diameter of the fluid.
Reynolds number formula can be used in the problems to calculate the Velocity (V), density (ρ), Viscosity (μ) and diameter (L) of the liquid.
The Kind of flow is based on the value of Re
- If Re < 2000, the flow is called Laminar
- If Re > 4000, the flow is called turbulent
- If 2000 < Re < 4000, the flow is called transition.
2.simulation parameters:
Initially the velocity of air is 10m/s flowing over the cylinder .we calculate the reynolds number on the basis of initial velocity.
The different parameter are :
diameter = 15mm
length of cylinder =50mm
initial velocity = 10m/s
dynamic viscosity of air = 1.81*10^-5 kg/ms
density of air = 1.225 kg/m3
Calculate the baseline case Reynolds number.
- Re = rho*U_inlet*D/mu
where,
- D = cylinder diameter
- mu = dynamic viscosity
- rho = density
Re =10151.94
At baseline Re= 10151.14 , v =10m/s
At 20% Re, Re =12182.328, v=12m/s
At 40% Re, Re =14212.716, v=14m/s
At 100% Re, Re =20303.88, v=20m/s
Results:
case1:
Re=10151.94 and velocity= 10m/s
Sumulation of velocity distribution:
Simulation of pressure distribution:
Animation of velocity at 10m/s:
Animation of pressure at 10 m/s :
case2:
Re=12182.328 and velocity= 12m/s
Sumulation of velocity distribution:
Sumulation of pressure distribution:
Animation of pressure at 12m/s:
Animation of velocity at 12m/s:
case3:
Re=14212.716and velocity= 14m/s
Sumulation of velocity distribution:
Sumulation of pressure distribution:
Animation of pressure at 14m/s:
Animation of velocity at 14m/s: