cfd t section pipe flow benchmarking

Flow through 90 degree diversions of rectangular cross-section

ME – 259 Introduction to Computational Fluid Dynamics

Prof. Dongmei Zhou

Presented By Pramod Krishnani

Fall 2007

Introduction CFD Model

Introduction Applications

Living Cardiovascular system

River channel Bifurcation

Fluent Settings CFD Simulation: 3ddp (3-D Double Precision)Convergence criteria:

Continuity = 1e-06 X- velocity = 1e-06 Y- velocity = 1e-06 Z- velocity = 1e-06

Discretization : Pressure : PRESTO Momentum equation setting = Second Order

UpwindSolver : Coupled

Boundary Conditions (BC)BC 1 : Main channel Velocity Inlet

BC 2 : Main channel Pressure Outlet

BC 3 : Branch Velocity outlet

Procedure For study Grid Independent Study

Creation of Different Mesh Files in GAMBIT ® Simulated in FLUENT® 3D Find Reattachment Length in Zone A Plot Truncation Error

Parameter Study Simulated

Scenario 1 : Used Cases In Benchmark Paper Scenario 2 : Change Fluid from water to Hydrogen Scenario 3 : Keeping Reynolds Number constant

changed Discharge Ratio

Grid Independent Study Simulation results of Reattachment Length in Zone A

Reattachment Length in Zone A

Analytical Resultfrom

Liepsch Paper

Mesh Size

Re-attachment

Lengthin Zone A (meters)

Error From

Analytical

% Error From

Analytical Or

Truncation error

Error From Best

Mesh Size

% Error From Best Mesh Size

Or Truncation

error

2.87704

148176 2.42857 0.44847 15.58789589 0.43507 15.19290134

453600 2.48654 0.3905 13.57297778 0.3771 13.16855471

1185408 2.64287 0.23417 8.139268137 0.22077 7.709418782

4000752 2.85714 0.0199 0.691683119 0.0065 0.226983839

4634784 2.86364 0.0134 0.465756472 0 0

Grid Independent Study Truncation Error Plots

Comparing with Liepsch Paper

Comparing with Best Mesh Size

Grid Independent Study Streamline plots of velocity of Case 1 at Z =

2.0

Grid Independent Study Comparison of velocity profiles at Z=4.0

plane

Grid Independent Study Skin Friction Plots At Outer wall Of The Main

ChannelSkin Friction Plots At Branch Left wallSkin Friction Plots At Branch Right Wall

Grid Independent Study Z-plots of Vorticity Profiles at different

positions of Y keeping X constant

Grid Independent Study Z-plots of Vorticity Profiles at different

positions of X keeping Y constant

Parameter Study Mesh Size Used : 81 x 70 x 80 Scenario Used

1. Study of Cases in Paper 2. Change of Fluid to Hydrogen 3. Keeping Re Constant Change Discharge

ratio ‘r’

Parameter Study Scenario 1 : Study of Cases in Paper

Case Reynold

Number AR

Discharge

Ratior

Main channel Velocity inlet

V1 = Ub (m/sec)

Branch Velocity Outlet

V2 (m/sec)

1 515 8 0.23 0.000258738 0.000059509

2 496 8 0.44 0.00024919 0.000109643

3 525 8 0.64 0.000026376 0.000168806

4 1062 8 0.58 0.000533548 0.000309458

5 496 1 0.44 0.00024919 0.000109643

Parameter Study Scenario 1 : Study of Cases in Paper

Velocity streamline plots of the simulation

Parameter Study Scenario 1 : Study of Cases in Paper

Velocity streamline plots of the Paper or benchmark

Parameter Study Scenario 2 : Change of Fluid to Hydrogen

Parameter Study Scenario 2 : Re-attachment Length

FluidReynolds number

Discharge Ratio ‘ r ’

Reattachment Length Xr (meters)

Water 496 0.44 2.48654

Hydrogen 496 0.44 3.2

Parameter Study Scenario 2 : Change of Fluid to Hydrogen

Parameter Study Scenario 3 : Keeping ‘Re’ Constant Change

Discharge ratio ‘r’Reynold Number

Discharge Ratio 'r' Main channel Inlet Velocity

V1 (m/sec)

Branch Velocity Outlet

V2 (m/sec)

515

0.23

0.000258738

0.000059509

0.75 0.000194053

1 0.000258738

1.5 0.000388107

2 0.000776214

Parameter Study Scenario

3 Velocity Streamline plot at r = 0.23

Parameter Study Scenario 3 Velocity Streamline plot at r = 0.75

Parameter Study Scenario 3 Velocity Streamline plot at r = 1.00

Parameter Study Scenario 3 Velocity Streamline plot at r = 1.50

Parameter Study Scenario 3 Velocity Streamline plot at r = 2.00

Conclusion Grid Independent Study

Comparing with Liepsch Paper

Comparing with Best Mesh Size

Conclusion Parameter Study Scenario 1

Conclusion Parameter Study Scenario 1

Conclusion Parameter Study Scenario 2

Conclusion Parameter Study Scenario 3

Conclusion Parameter Study Scenario 3

Conclusion Parameter Study Scenario 3

Conclusion Parameter Study Scenario 3

Conclusion Parameter Study Scenario 3

Questions