me final presentation

8/2/2019 Me Final Presentation

1/22

Thermal and Structural Analysis of a

Combustion Test Apparatus using

ANSYSAdam Decker

Brandon Underwood

Matt Greathouse

Scott Andrews

ME 450 Dr. Nemah MW 430 PM 545 PM

Fall 2008


2/22

Objectives

Structural Analysis on the fuel tank filled with

a propane and air mixture if an explosion

occurs.

Transient Thermal Analysis on the test cell to

test if the temperatures will be too high for

the current design.


3/22

Introduction

Tank

Test Cell


4/22

Theoretical Background


5/22

Combustion

Chamber Heat

Transfer Analysis

A simulation wasrun to find

whether the entire

chamber could

heat to the point

where any special

precautions would

need to be taken.


6/22

Fuel/Air Mix Behavior

What would the characteristics be of the fuel/air

mixture during the combustion process?

What equations would be needed to find this

information?

What is the convection heat transfer coefficient,

enabling ANSYS to simulate the heat transfer

from the combustion to the chamber walls?


7/22

Equations

1. Hydraulic Diameter

2. Reynolds Number

3. Friction Factor

4. Nusselt Number

5. Convection Coefficient


8/22

Tank Explosion

Analysis

A simulation wasrun to predict what

could happen if

multiple part

failures were to

occur causing the

ignition of the

tanks fuel/air mix.


9/22

Maximum Pressure

First, find the maximum possible pressure for

the combustion temperature using ideal gas

law.

PV=nRTDouble this pressure to simulate the combustion

shockwave.


10/22

Explosion analysis model details

Modeled in ProE

Imported into ANSYS

Workbench

Static structural analysis 7285 nodes

3605 elements


11/22

Materials and conditions

Structural steel

0 DOF on base of tank

Constant 20 C temperature 36259 psi Yield strength

66717 psi Ultimate strength


12/22

Application of loads

Steps Time [s] Pressure [psi]

10. 0.

1.e-002 3000.

22.e-002

1442.79.

3 10. 0.

Pressure loading on

interior surface

10ms overpressure

simulates shock wave ofexplosion

Ramp loading better

simulates real world

behavior


13/22

Tank analysis results

42897 psi maximum

stress

Greater than yield

stress Less than ultimate

stress of 66717 psi

Tank should be replacedif an explosion occurs


14/22

Thermal analysis model details

Modeled in ProE

Imported into ANSYS

Workbench

Transient thermalanalysis

Block contained

14228 nodes 8112 elements


15/22

Materials and conditions

Aluminum

Initially 20 C

1.5ms for 60%

combustion

StepStepEndTime

InitialTimeStep

Minimum Time

Step

Maximum Time

Step

11.5e-003 s

1.5e-005 s

1.5e-006 s

1.5e-004 s

2 1. s9.985e-

003 s

9.985e-

004 s

9.985e-

002 s

3 2. s1.e-002

s1.e-003

s0.1 s


16/22

Application of loads

Natural convection

Vertical surfaces

Horizontal surfaces

Forced turbulentconvection

h=5.2527e-005

BTU/sinF

Radiation

=.1

Steps Time [s]ConvectionCoefficient

[BTU/sinF]

Temperature[F]

1

0. = 5.2527e-005 = 2240.

1.5e-0035.2527e-005

2240.

2 1. 1340.3

3 2. 0. 68.

Steps Time [s] Temperature [F]1

0. = 2240.

1.5e-003 2240.

2 1. 1340.3

3 2. 32.


17/22

Block analysis results

Maximum

temperature 87.231 F

Temperature on

outside of blockremains even lower

No danger to

components hooked

up to the outside


18/22

Impact Statement- Societal

Propane:

-majority of used is produced domestically

-nearly 80 percent of farms use to run pumpsand engines, dry crops, heat buildings, process

foods, and reduce emissions.

-more than 10 million vehicles around the

world use propane


19/22

Impact Statement - Environmental

Propane:

low carbon count (per BTU)

emmisions are much cleaner

has relatively gentle human toxicity characteristics

not a potential contributor to groundwater

pollution


20/22

Impact Statement - Safety

Flammability

Propane can create gaseous hydrogen (which

can be a flammable issue)


21/22

Conclusion

Structural Analysis showed no catastophic

failures in tank. Will need replaced if a failure

occurs.

Thermal analysis showed that the test cell will

not reach temperatures that could damage

other components.


22/22

Bibliography

Moaveni, Saeed. Finite Element Analysis:

Theory and Application with ANSYS. Upper

Saddle River: Pearson Prentice Hall, 2008.

Incropera, Frank P., David P. Dewitt, Theodore

L. Bergman, and Adrienne S. Lavine.

Fundamentals of Heat and Mass Transfer.

Hoboken: John Wiley & Sons Inc., 2007.

me final presentation

Documents