This masters thesis defense presentation summarizes the student's research on modeling lunar dust removal. Part I discusses developing a tracking algorithm to study the effect of irregular particle shape on migration. Variables like drag and lift coefficients were calculated for different shapes. Part II examines designing and simulating different dust remover models, finding that a pear shape with swirl flow performed best by removing all particles within 21 seconds using 12.6 kg of air. The student concludes the pear shaped design with swirl flow is the most effective lunar dust removal system studied.

1. MASTERS THESIS DEFENSE
REMOVAL OF LUNAR DUST INSIDE CONFINED SPACE AND
EFFECT OF SHAPE IRREGULARITY ON PARTICLE
MIGRATION
Presented By
Prashant M. Ghadge
Advisor : Dr. Xianchang Li
Department of Mechanical Engineering
(Lamar University, Beaumont, Texas)

2. Part I
Tracking of Irregular Shaped
Particle
Part II
Modeling and Simulation
of Lunar Dust Remover

3. PART I: TASKS
1. Literature review
2. Effect of shape on force coefficients
3. Tracking algorithm
4. Application of UDF
5. Particle tracking
6. Results

4. STUDY OF SHAPE
Various Shapes Moon dust from Apollo 11
Source:<www.sandgrains.com>

5. MOTION STUDY
ΔT (Time Step)
ΔT
Translation + Rotation
(CD & CL) (T & θ)

6. TRANSLATION
START
I, m, θ, CD, CL & T
From θ  T
α=T/I CD & C L
ω = ω0 + αt
θp = θ0 + ωt + ½ αt2
θf = tan-1(Vyrel/Vxrel)
Y
θ = θp - θ f
Steps θ  CD and FD
or θ0 = θ and ω0= ω
Domain
N
STOP

7. MODEL TO STUDY TRANSLATION
Elliptical Barrier
V
Y
X
0.05 X 0.1 m
2D flow path
Elliptical barrier tilted
at different angle

8. FORCES ACTING ON THE BARRIER
FD = Drag force (N)
FD = CD 1/2 ρ V2 A
Lift FL = Lift force (N)
Drag FL = CL 1/2 ρ V2 A
Gravity CD = Drag coefficient
CL = Lift coefficient
ρ = Density of fluid
V = Flow velocity
A = Characteristic frontal
Velocity vectors at elliptical barrier area of the body

9. VARIATION WITH ANGLE
Variation of Coefficient Variation of Coefficient
of Drag of Lift

10. VARIATION OF CD WITH ANGLE

11. ROTATION
START
I, m, θ, CD, CL & T
From θ  T
α=T/I Torque T
ω = ω0 + αt
θp = θ0 + ωt + ½ αt2
θf = tan-1(Vyrel/Vxrel)
Y
θ = θp - θ f
Steps θ  CD and FD
or θ0 = θ and ω0= ω
Domain
N
STOP

12. STUDY OF TORQUE
Shear Force Pressure Force
Torque = Force × Displacement

13. VARYING TORQUE WITH ANGLE

14. UDF FOR ELLIPTICAL PARTICLE
Relative Reynolds
Number
Drag
Lift
Relative Angle

15. STRAIGHT CHANNEL
6.4
Spherical
Particle Track
0 Sec
Comparison of
Spherical & Elliptical
Particle Track

16. ELBOW CHANNEL
5m
133
5m
Y
X
0 Sec
Comparison of
Spherical
Spherical & Elliptical
Particle Track
Particle Track

17. RESULTS AND DISCUSSION
From the study of forces
 CD and CL decreases with Re
 T increases with Re
 Graph follows similar pattern
 SHAPE is important factor

18. PART II : LUNAR DUST REMOVER
Inlet
Inner Door
Blower
Air
Filter Dust
Remover Enclosed
Capsule
Outer Door Wall
Outlet

19. BOUNDARY CONDITIONS AND PARAMETERS
Boundary Conditions Parameters
1. Inlet : Velocity inlet 1. Velocity = 4 m/s
2. Outlet : Pressure Outlet 2. Swirl components :
3. Sidewall : Wall Radial = 0.3
Tangential = 0.3
4. Object : Wall Axial = -1
3. Re = 250,000

20. RECTANGULAR MODEL
18
0 Sec
Velocity Pathlines Particle Track
Pro-E model Simple flow Swirl flow

21. CYLINDRICAL MODEL
11.8 1
0 Sec 0 m/s
Particle Track Velocity Pathlines
Pro-E model Simple flow Swirl flow

22. MORE DUST REMOVER MODEL
Dome Shaped Model Pear Shaped Model

23. DOME SHAPED MODEL
Velocity pathlines and vectors Particle track
Simple flow Swirl flow

24. PEAR SHAPED MODEL
Velocity vectors Particle track
Swirl flow Swirl flow

25. COMPARISON: PARTICLE ESCAPED
Particle Escaped
Model Flow type out of 100
In 30 Sec. In 60 Sec.
Simple 28 37
Rectangular
Swirl 30 54
Simple 52 75
Cylindrical
Swirl 32 50
Simple 85 89
Dome Shape
Swirl 57 87
Simple 47 49
Pear Shape
Swirl 100 100

26. COMPARISON OF MODELS
Particles
Removed
Out of 100
Models

27. RESULTS AND DISCUSSION
From the study of Lunar dust remover
 Pear Shaped Model:
I. Particle Escaped = 100
II. Maximum Time = 21 Sec
III. Mass of Air Needed = 12.6 kg
IV. Better Design

28. CONCLUSION
1. UDF for lift, drag and torque
2. Tracking of elliptical particle
3. Model: Pear shaped
4. Flow: Swirl

29. THANK YOU