Frisbee Aerodynamics

Corentin Richard Mark Schnittman ME165 May 3, 2004

Flight Mechanics Translational Motion (U∞) Rotational Motion (Ω) Lift Drag Center of Pressure (cp) Moments

Experimental Data

Jonathan R. Potts & William J. Crowther Fluid Mechanics Research Group, School of Engineering University of Manchester, U.K.

Project Goals Verify Significance of Rotation Compare Lift Compare Drag Compare Center of Pressure

Jonathan R. Potts & William J. Crowther Fluid Mechanics Research Group, School of Engineering University of Manchester, U.K.

Frisbee Geometry

Precise 2D

Simplified 3D

Model Geometry Duct Radius: Duct Length: Elements:

.2 m .7 m ~5000

Inlet: Outlet: Duct Walls: Symmetry Frisbee: Frisbee: vz v = -

U∞ P=0

No Slip vx + vy +

x

y*Ω∗cos(α) vy = -x*Ω vz = y*Ω∗sin(α) where α is Angle of Attack

2D Streamlines

2D Streamlines

2D Streamlines

3D Streamlines

Effect of Rotation No Spin, U = 1 m/s AoA Lift 5º 0.756 10º 0.482

Ω = 10 rad/s, U = 1 m/s AoA Lift 5º 0.482 10º 0.823

Angle of Attack Flight Speed = 1 m/s Rotation = 0 Pressure Charts

5º Attack

0º Attack

10º Attack

Visual Comparison Advance Ratio ~ 0 (negligible rotation) Symmetric Wake

Visual Comparison Advance Ratio ~ U = .6*Ω Asymmetric Wake

Collected Data AoA=0 degree Speed

Fd

Cd

Fl

Cl

center

1

0.011

2.350427

0.0056

0.175882

0.09

1+spin

0.012

2.564103

0.0083

0.260682

0.099

5

0.155

1.324786

0.161

0.202264

0.078

Speed

Fd

Cd

Fl

Cl

center

1

0.013

1.748296

0.0147

0.463451

0.014

1+spin

0.013

1.748296

0.0153

0.482367

0.032

6

0.23

0.859206

0.437

0.382706

0.02

Speed

Fd

Cd

Fl

Cl

center

1

0.016

2.167266

0.0237

0.755827

-0.0032

1

0.0152

2.058903

0.0258

0.822799

0.0028

AoA=5 degree

AoA=10 degree

Data Comparison Reynolds number in the simulation is 15 times smaller than in experimental data. Lift coefficient

Drag coefficient

2D Dynamic Simulation AoA = 0º

Flight Speed = 10m/s

2D Dynamic Simulation AoA = 10º

Flight Speed = 10m/s

Conclusion Overall Flow Trends Look Plausible Lift Correlates Very Well Drag Correlates Poorly Center of Pressure is Questionable

Higher Flight Velocities Necessary Higher Rotational Velocities Necessary

This will allow better comparison to wind tunnel data and thereby allow better validation of computational model