TO PIPE FLOW SIMULATION BY USING SOLIDWORKS
AIM :
To perform the flow simulation at inside the circular pipe by using dimensionless number like reynolds number and extracting datas from numerical model such as post processing.
FLOW OF CONTENT/METHODOLOGY :
OBJECTIVE :
1) To calculate inlet velocity of the fluid by using reynolds number.
2) Create a mathematical model with constrained dimensions by using solidworks modelling software.
3) Descritization the mathematical model.
4) Extracting datas from the numerical model (Post processing).
INTRODUCTION :
Computational fluid dynamics is a science that, with the help of digital computers, produces quantitative predictions of fluid flows phenomena based on Navier stroke equation is consists of conservation laws such as time dependent continuity equation for conservation of mass, three time dependent conservation of momentum equation and a time dependent conservation of energy equation.
Boundary layer formation:
The boundary layer in fluid mechanics, thin layer is forming when fluid flows over the surface. Due to shear stress between pipe interior surface and fluid layer. The entrance of fluid velocity is same along the radial direction, the boundary layer forms when the fluid flows throughs along the pipe. Due to viscosity, as the property of a fluid which offers resistance to the movement of one layer of fluid over another adjacent layer of the fluid. Our fluid is real, because which is possess the viscosity.
Develping region :
Inbetween the entrance and merge point is a developing region. The velocity gradient is changing over the length till boundary layer merge or velocity profile is varying. That region is called Hydrodynamic entrance region.
Fully developing region :
After the hydrodynamic entrance region, the fluid is achieved the fully developed profile or region and velocity gradient is remains same untill pipe end.
Inviscid region :
The irrotational flow region annotation is a inviscid flow region, there is no viscosity is there.
Dimensionless Number
A dimensionless number are those number which are obtained by dividing the inertia force by viscuous force or gravity force or pressure force or surface tension force or elastic force. As this is a ratio of one force to the other force, it will be a dimensionless number. These dimensionless numbers are also called non dimensional parameters. The followings are the important dimensionless numbers:
1) Reynold's Number
2) Froude's Number
3) Euler's Number
4) Weber's Number
5) Mach's Number
We are only looking at reynold's number, it is a important role for identifying the either the fluid flow condition is laminer or turbulent or transition.
Reynold's Number
It is defined as the ratio of inertia force of a flowing fluid and the viscous force of the fluid. The expression for reynold's number is obtained as
Reynold's Number,`Re = (rhotimesvtimesD)/mu`
= `(v*D)/nu` `because mu/rho = nu`
Where,
`rho =`density (kg/m^3)
v = Velocity (m/sec)
D = Diameter of pipe (m)
`nu =` Kinematic viscosity (m^2/sec)
`mu =`Dynamic viscosity (Ns/m^2)
Finding fluid flow condition by using reynolds number value
1) The reynolds number value is less than 2000, it is called laminer flow.
2) The reynold number value is greater than 4000, it is called turbulent flow.
3) The reynold number value in inbetween value of 2000 and 4000, it is called transitional flow.
ANALYTICAL CALCULATION :
Assume values :
Temperature at 298 K
Dynamic Viscosity = 0.7191*10^-6 N/m^2
Kinematic Viscosity = 0.7239*10^-6 m^2/sec
Density = 999 kg/^3
Reynold's number = 100
Reynold's Number,`Re = (rhotimesvtimesD)/mu`
= `(mu times Re)/(rho times A)`
= `(Re times nu)/(A)`
= `(100 times 0.7239*10^-6)/((pi/4) times (0.019)^2)`
`V = 0.0634062 m/sec`
Reynold's number = 1000
Reynold's Number,`Re = (rhotimesvtimesD)/mu`
= `(mu times Re)/(rho times A)`
= `(Re times nu)/(A)`
= `(1000 times 0.7239*10^-6)/((pi/4) times (0.019)^2)`
`V = 0.634062 m/sec`
Reynold's number = 10000
Reynold's Number,`Re = (rhotimesvtimesD)/mu`
= `(mu times Re)/(rho times A)`
= `(Re times nu)/(A)`
= `(10000 times 0.7239*10^-6)/((pi/4) times (0.019)^2)`
`V = 6.34062 m/sec`
CREATE THE FLUID FLOW DOMAIN
To create a pipe by using circle, extrude bose base and shell graphical user interface with appropriated dimensions. Moreover, to create a two dimensional line at 0.85, 0.90 and 0.95 total length of pipe. These lines are used to extracting the velocity profile for different reynolds number and also to plane at entrance of the pipe.
Pipe geometry dimensions
Outer diameter = 0.02 m
Inner diameter = 0.019 m
Length of the pipe = 1 m
ANALYSIS TYPE :
Unit system : SI
Analysis type : Internal flow
Working fluid : Water
Initialization parameters and values
DISCRITIZATION :
The process of discritize the mathematical domain is dividing into finite element to prepare for analysis is called meshing. Most of the case, Computational fluid dynamics calculating method is finite volumue method, in same time finite element method also been used.
Before doing an mesh, the domain has been completely closed. we use Led option, to cover the entrance and exit path.
Mesh Specifications :
Element type : Hexahedral
Number of element in x direction : 10
Number of element in y direction : 10
Number of element in z direction : 60
BOUNDARY CONDITIONS :
Inlet boundary condition :
We select the flow opening option for fix the inlet boundary condtion is velocity type. Provide the velocity and did not select the fully developed region. Because, developed region only formed till the merge point.
Outlet boundary condition
We select the pressure opening for fix the boundary condition is pressure type. The pressure value is already loaded at one atmospheric pressure in pascal, it's a referance pressure or Gauge pressure. By end of the solving the mathematical domain, we can easily identified the pressure along the pipe.
Wall boundary condition
We select the wall type option, velocity at wall surface is zero.
PARAMETRIC STUDY :
First of all, add the simulation parameter for velocity So it's called velocity dependent solution. Load the three velocity into calculation. Set the legend showing type in plot minimum and plot maximum and run the parametric test.
Add the wanted the results and run the calculation and extracting useful data from computational numerical domain.
POST PROCESSING
Velocity profile at 0.85 times of pipe length from inlet for Re 100, 1000 & 10000
Design point 1 sketch4 is a velocity profile for reynolds number 100
Design point 1 sketch4 is a velocity profile for reynolds number 1000
Design point 1 sketch4 is a velocity profile for reynolds number 10000
There is less inlet velocity, the velocity gradient is also infintesimal small. Next case, the inlet velocity is little bit high compare to previous one, so that the velocity gradient is bit varying along radial direction. Final case, the reynolds number is very high compare to previous both cases, the velocity gradient is highly varying along radial direction.
Velocity profile at 0.90 times of pipe length from inlet for Re 100, 1000 & 10000
Compare to previous one, there is no varying inbetween distance from 0.80 to 0.85 total length of the pipe.
Velocity profile at 0.95 times of pipe length from inlet for Re 100, 1000 & 10000
Compare to previous both two profiles, there is no varying inbetween distance from 0.80 to 0.95 total length of the pipe.
COMPARISION OF VELOCITY PROFILE FOR ALL CASES
Comparing the all cases in single plot, the three case velocity profile is coincidence at same path.
VELOCITY PLANE CONTOUR AT INLET
Velocity plane for reynolds number 100
Velocity plane for reynolds number 100
Velocity plane for reynolds number 100
VELOCITY CUT PLANE CONTOUR FOR REYNOLDS NUMBER 100
0.85 times length from the total length of the pipe
0.90 times length from the total length of the pipe
0.95 times length from the total length of the pipe
VELOCITY CUT PLANE CONTOUR FOR REYNOLDS NUMBER 1000
0.85 times length from the total length of the pipe
0.90 times length from the total length of the pipe
0.95 times length from the total length of the pipe
VELOCITY CUT PLANE CONTOUR FOR REYNOLDS NUMBER 10000
0.85 times length from the total length of the pipe
0.90 times length from the total length of the pipe
0.95 times length from the total length of the pipe
CONCLUSION :
1) Finally, we run the simulation for reynolds number 100, 1000 & 10000 and also data extracted from line probe and make it in plot.
2) Calculated velocity dependent solution from parametric study.
3) Comparing the obtained plot from all probe lines to single plot.
REFERANCES :
1) https://wiki.anton-paar.com/in-en/water/
2) https://en.wikipedia.org/wiki/Computational_fluid_dynamics