Flow simulation through a pipe using Solidworks
Flow Simulation through a Pipe.
Aim: To create a flow to simulation through a pipe and analyze it.
Objective:
- Create flow simulation through a pipe by using Flow simulation feature in solidworks.
- Specify boundaries, properties of fluid, plots to be obtained.
- Make plots, cut sections for easy understanding of output.
- Examine the output given after running the simulation.
Theory:
Flow simulation:
Flow simulation is a form of computational fluid dynamics which digitally replicates flows in surface water or collection systems. Performing flow simulation allows for the prediction and analysis of how a flow might be impacted by complex geometry in an operational environment. Flow simulation is not limited to liquids and may be applied to gases as well. It is especially useful in trenchless applications to predict how a system will behave in low and high use situations, such as dry vs. storm weather simulations for drainage systems.
Flow simulation can be used to identify and develop solutions and methods, as well as predict the effect of changes to a system. At times, however, the observed flow may differ from simulated flows. In these cases the estimated flow simulation needs to be updated with measured data.
When a fluid is flowing through a closed channel such as a pipe or between two flat plates, either of two types of flow may occur depending on the velocity and viscosity of the fluid: laminar flow or turbulent flow.
Laminar flow:
In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids. In laminar flow, the motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection. It is also found that a flow in a pipe is laminar if the Reynolds Number (based on diameter of the pipe) is less than 2100.
Turbulent flow:
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. It is also found that a flow in a pipe is turbulent if the Reynolds Number (based on diameter of the pipe) is greater than 4000.
In this project both the flows are considered while performing the simulation.
Procedure performed during the preparation of project.
Creating a pipe through which the fluid is flowing
The output for studying is taken across three probes made at 95%, 90% and 85% of total length and situated at outlet of the pipe. The probes are shown by the colored lines.
Red – 95% (0.05m form the end of pipe)
Green – 90% (0.1m form the end of pipe)
Yellow 95% (0.15m form the end of pipe)
In flow simulation assigning the input data
Here the values specified are kept at default.
Assigning the boundary conditions for inlet, outlet and wall of the pipe.
At inlet, velocity should be specified. The velocity is calculated on the basis of values of Reynolds number given as 100, 1000, 10000.
Formula
After that, mesh is edited by selecting the manual option and by specifying the required values of 10 in X direction, 10 in Y direction and 50 in Z direction to achieve detailed results in reasonable time.
Next is to insert the plots in result section which we want to get as an output.
After setting up all as above, a new parametric study is to be created.
In structure two more design points are added having the change in velocity shown as above.
RESULTS
Case 1: @Re = 100
Cut plot velocity at 95%
Cut plot velocity at 90%
Cut plot velocity at 85%
Cut plot of pipe
Case 2: @Re = 1000
Cut plot velocity at 95%
Cut plot velocity at 90%
Cut plot velocity at 85%
Cut plot of pipe
Case 3: @Re = 10000
Cut plot velocity at 95%
Cut plot velocity at 90%
Cut plot velocity at 85%
Cut plot of pipe
Velocity plots for all cases (combined):
Velocity at 95%
Velocity at 90%
Velocity at 85%
Comparison of velocities
Conclusion: As studied above there is not much difference in the values of the velocities among the three cases. The difference in values can be seen in the velocity comparison plot. If the values of mesh are adjusted to a higher value then the smoothness in the cut plot is observed. The flow across the sections considered in the geometry are almost same.
Reference:
https://en.wikipedia.org/wiki/Turbulence
G-drive link for accessing the data of velocity comparison plot.
https://drive.google.com/file/d/1YGiq3z_ucGEiY7EhCCphM2cgsow8wszi/view?usp=sharing