Fluid Engineering

1. TITLE
A COMPARATIVE STUDY OF
COMPUTATIONAL FLUID DYNAMICS
SIMULATION OF LAMINAR FLOW IN
PIPE

2. Roll.No. Name PRN No.
3 Pruthviraj Chavan 12320135
5 Aarti Gurav 12320190
11 Tushar Khade 12320227
13 Saniya Pathan 12320193
18 Atharva Suryavanshi 12320169
23 Yuvrajsingh Pardeshi 12320168
DIV - C, BATCH - 3, GROUP -4

3. TABLE OF CONTENT
 Introduction
 What Is Laminar Flow?
 Boundary layer For Laminar Flow
 Explanation Reynolds Numbers For Laminar &
Turbulent Flow
 CFD Simulation
 Results
 Conclusion

4. INTRODUCTION
 Laminar flow is a fundamental concept in fluid dynamics, describing the
movement of a fluid in orderly layers without turbulence.
 It occurs when a fluid, such as air or water, flows smoothly in parallel paths,
with each layer sliding past the adjacent layer in a predictable manner.
This flow pattern is typically observed at lower velocities or in fluids with higher
viscosity.
Laminar flow has applications in various fields, from engineering and physics to
biology and industry, influencing designs in pipes, aircraft wings, blood vessels,
and more.
Understanding laminar flow helps optimize systems and designs for efficient
and controlled fluid movement.

5. What is Laminar Flow?
 Laminar flow refers to the smooth, orderly
movement of fluid (liquid or gas) in parallel layers
without turbulence.
In this type of flow, the fluid moves in a regular
manner, with each layer of the fluid flowing in a
continuous path without disrupting adjacent layers.
It's characterized by its predictable and steady
motion, commonly observed in situations with low
fluid velocity or high viscosity.

6. Boundary Layer For Laminar Flow
• No-slip condition: The no-slip condition still holds for internal
flows. At the pipe or channel wall, the water velocity is zero
due to viscosity, and it gradually increases moving away from
the wall.
• Velocity profile: The velocity profile in the boundary layer
depends on whether the flow is laminar or turbulent. In laminar
flow, the velocity profile is typically parabolic, similar to what
you would find in external laminar boundary layers. In
turbulent flow, the velocity profile is flatter and more uniform
across the pipe or channel.

7. • Laminar and Turbulent Transition: The transition from laminar to turbulent flow
in internal flows is influenced by the Reynolds number (Re), similar to external
flows. For water flow in pipes, the transition from laminar to turbulent flow often
occurs at a lower Reynolds number compared to external flows.
• Boundary Layer Thickness: Boundary layer thickness is the perpendicular
distance from the solid surface at which the velocity of the fluid becomes equal to
0.99 times the free stream velocity of the fluid approaching toward the solid
surface.

8. Explanation Reynolds numbers for laminar
& turbulent flow
The Reynolds Number (Re) Is A Dimensionless
Parameter Used To Predict The Type Of Flow In A Fluid
System. It's Defined As The Ratio Of Inertial Forces To
Viscous Forces Within The Fluid.
For Laminar Flow:
Low Reynolds Numbers (Typically Below 2,300 For
Internal Flows) Indicate Laminar Flow.
In Laminar Flow, Viscous Forces Dominate Over Inertial
Forces, Resulting In Smooth, Orderly Fluid Motion With
Well-defined Layers That Move Parallel To Each Other.

9. For Turbulent Flow:
Higher Reynolds Numbers (Usually Above 4,000 For Internal Flows) Indicate
Turbulent Flow.
Turbulent Flow Occurs When Inertial Forces Are Predominant Over Viscous Forces,
Leading To Chaotic, Irregular Fluid Movement Characterized By Eddies, Mixing, And
Fluctuations In Velocity And Pressure.
There's A Transitional Range Between These Two Regimes Where Flow Behavior
Can Be Both Laminar And Turbulent, And This Transition Range Typically Falls
Between Reynolds Numbers Of 2,300 To 4,000 For Internal Flows.
Understanding Reynolds Numbers Helps In Predicting The Type Of Flow Within A
System And Is Crucial For Designing And Analyzing Fluid Flow In Various
Engineering Applications.

10. Calculations:
Let’s take
V= inlet velocity
Pipe ID (D) =100 mm
Pipe OD (D1)=106 mm,
For laminar flow through pipe, Reynolds No. Re < 4000.
Let’s take Re =100
Dynamic Viscosity of Fluid(water)=0.001003 Kg/m.s
We know,

11. Using this formula we get inlet velocity V=0.001005 m/s
Now, Length of pipe
Entrance length of laminar Flow Le=Re*0.7*D
= 100*0.7*0.1
= 0.7m
So , Let’s take length of pipe =1.5m=1500mm

12. CFD Simulation
Simulating laminar flow in a pipe using ANSYS or any other
computational fluid dynamics (CFD) software doesn't involve a
physical experimental setup, as it's a virtual simulation. Instead,
you will set up and define the simulation parameters within the
software. Here's an overview of how you can set up a CFD
simulation for laminar flow in a pipe using ANSYS:
1.Geometry Modeling:
Start by creating or importing the 3D geometry of the pipe and
the surrounding domain.
Inner diameter=100 mm
Outer diameter=106 mm
Length= 1500mm

13. 2.Mesh Generation:
Create A Mesh That Discretizes The Geometry Into Smaller Elements. For A
Laminar Flow Simulation, It's Essential To Have A Fine Mesh Near The Pipe
Walls And The Regions Of Interest.
3.Setup
General-pressure based
Model- Viscous-laminar
Material- liguid-water
4.Boundary Conditions:
Define The Boundary Conditions For The Simulation.
Inlet velocity=0.001005m/s
Outlet pressure=1atm
Gauge pressure= 0

14. 5.Initialization:
 Standard initialization
Computing from inlet
6.Run The calculations
Number of literations-1000
 Execute The Simulation Using ANSYS. The Software Will Solve The Fluid Flow
Equations Iteratively To Compute The Flow Field Within The Pipe.

15. 7.Data Analysis:
 After the simulation is complete, analyze the results to extract the desired information
about the laminar flow within the pipe. ANSYS provides various tools for post-
processing, visualization, and data extraction.
 In summary, simulating laminar flow in a pipe with ANSYS involves setting up the
computational model, defining boundary conditions, running the simulation, and
analyzing the results. It's a virtual representation of the flow behavior within the pipe
and does not require a physical experimental setup.
Fig 1 flow at inlet (velocity) Fig 2 flow at outlet (velocity) Fig 3 Change in static pressure from inlet to outlet

16. VELOCITY PROFILE (PARABOLIC)

17. RESULTS
The computational simulation of laminar flow in pipes using ANSYS has
provided valuable insights into the behavior of fluids under controlled
conditions. The analysis of the simulation results has produced several key
findings:
1. Velocity Distribution:
 The velocity distribution within the pipe exhibits the classic parabolic profile
associated with laminar flow. As expected, the center of the pipe
experiences the highest velocity, gradually decreasing toward the pipe walls.

18. 2. Pressure Distribution:
The Pressure Distribution Along The Pipe Length
Conforms To The Pressure Drop Characteristics Of
Laminar Flow. The Simulation Results Reaffirm The
Gradual Increase In Pressure Drop As The Flow Rate
Rises Within The Laminar Flow Regime.
3. Stability and Predictability:
 The Laminar Flow Behavior Observed In The Simulation
Emphasizes Its Stability And Predictability. Fluid Layers
Move Smoothly In Parallel, With Minimal Mixing And
Turbulence

19. 4. Efficiency and Applications:
 The Results Of The Simulation Have Practical Implications For
Engineering Applications.
Laminar Flow's Orderly And Predictable Nature Makes It A Preferred State
In Scenarios Where Efficiency Is Crucial. These Applications Include Fluid
Transport Systems, Heat Exchangers, And Chemical Reactors, Where
Laminar Flow Can Minimize Energy Loss And Enhance Heat Transfer
Efficiency.

20. CONCLUSION
In conclusion, the simulation of laminar flow in pipes using ANSYS has
provided a comprehensive understanding of the behavior of laminar fluids
within a controlled environment. The key takeaway points are as follows:
1. The simulation accurately reproduced the parabolic velocity distribution
and linear pressure drop relationship associated with laminar flow.
2. The orderly and organized behavior of laminar flow was observed,
highlighting its predictability and energy-efficient properties.

21. These findings have practical implications for engineering applications, particularly
in the design and optimization of fluid transport systems, heat exchangers, and
chemical reactors. Laminar flow's predictable nature and minimal energy loss
make it a preferred state in scenarios where efficiency is of paramount
importance.

22. THANK YOU