107 poster

Testing Preparations Abstract There are different parameters that affect how well a Frisbee performs. The purpose of this research was to characterize the fluid dynamic performance effects when changing the top-face curvature of a Frisbee. Curvature values ranged from [0, 0.2, 0.5, 0.75, 1, 1.25”] and other physical and fluid dynamic parameters were taken into account. Ultimately, the results indicate that an increase in radial curvature is directly proportional to the generated lift force, while inversely proportional to drag. In addition, higher angular velocities counteract Frisbee instabilities and increase flight time. Acknowledgments • Lisa Sohn, Ph.D., David Fernandez – Mentors • Jesse Lopez, Pete Graham – Machining • Cal NERDS – Poster printing Sponsor • Alco-Iron & Metals – Materials Sponsor ↔ Tests - Results Conclusions • Increasing the curvature, decreases the drag force • Increasing the curvature, increases the lift force • The most optimal Frisbee based on what we tested is the 1inch radius of curvature • Higher angular velocity will help the Frisbee remain more stable and counteract the downward forces Alejandro Cota, Setareh Ganji, Mohamad Mirzaei, HeeYeon Kwon, David Fernandez, Lisa Sohn, Ph. D. Department of Mechanical Engineering, University of California, Berkeley, CA 94720 References Munson, B., & Okiishi, T. (2013). Fundamentals of fluid mechanics (7th ed.). Hoboken, NJ: John Wiley & Sons. Figure 1: No Curve For further information Alejandro Cota – Mechanical Engineering ‘15 Setareh Ganji – Mechanical Engineering ‘15 Mohamad Mirzaei – Mechanical Engineering ‘15 HeeYeon Kwon – Mechanical Engineering ‘16 OPTIMIZING FRISBEE FLUID D YNAMICS VIA NON-DIMENSIONAL D YNAMIC SIMILITUDE TESTING Background To apply Buckingham Pi Theorem and perform the dimensional analysis we must first decide on the factors, or variables, that we expect will have an effect on the performance of the Frisbee. We foresee the list to include : Difficulties Encountered Difficulties: - Shaft vibrations - Frisbee wobbling - Time Figure 2: 0.2" Please visit: http://teammash.edublogs.org/ Solutions: - Trimmed shaft, and increased stability by implementing more points of contact - Increased size of center clearance hole to avoid threads and mechanical binding - Concentrated on one parameter (vary curvature), and adjusted to proper number of data points to save time Figure 3: 0.5" Figure 4: 0.75" Figure 5: 1" Figure 6: 1.25" μ air : Fluid Dynamic Viscosity ω : Frisbee Angular Velocity α : Angle of Attack ρ air : Fluid Density V air : Wind Speed d : Frisbee diameter F : Force (Lift/Drag) 2 2 1 h V F Model Model Model d ρV Re ) ( air ir * a 2 h d Model 3 m 4 Model Figure 13: Best 1” Curvature y = 40.049x 3 - 183.68x 2 + 296.51x - 149.72 R² = 0.9992 0 5 10 15 20 25 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Wind Velocity (m/s) Pressure Transucer Voltage (V) Wind Tunnel Calibration Curve Trans Pressure vs. Velocity Poly. (Trans Pressure vs. Velocity) Figure 8: Frisbee geometry layout. Figure 9: 2-axis mill to add Frisbee thickness Figure 10: CNC-Lathe to create the Frisbee curvature. Figure 11: Connecting rod to join DC-Motor and Frisbee. Figure 12: DC-Motor provides spin to the Frisbee. Figure 7: Positive is Counter-Clockwise.

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Transcript of 107 poster

Testing Preparations

Abstract There are different parameters that affect how well a Frisbee

performs. The purpose of this research was to characterize the

fluid dynamic performance effects when changing the top-face

curvature of a Frisbee. Curvature values ranged from [0, 0.2,

0.5, 0.75, 1, 1.25”] and other physical and fluid dynamic

parameters were taken into account. Ultimately, the results

indicate that an increase in radial curvature is directly

proportional to the generated lift force, while inversely

proportional to drag. In addition, higher angular velocities

counteract Frisbee instabilities and increase flight time.

Acknowledgments • Lisa Sohn, Ph.D., David Fernandez – Mentors

• Jesse Lopez, Pete Graham – Machining

• Cal NERDS – Poster printing Sponsor

• Alco-Iron & Metals – Materials Sponsor ↔

Tests - Results

Conclusions • Increasing the curvature, decreases the drag force

• Increasing the curvature, increases the lift force

• The most optimal Frisbee based on what we tested is the 1inch radius of curvature

• Higher angular velocity will help the Frisbee remain more stable and counteract the downward forces

Alejandro Cota, Setareh Ganji, Mohamad Mirzaei, HeeYeon Kwon, David Fernandez, Lisa Sohn, Ph. D. Department of Mechanical Engineering, University of California, Berkeley, CA 94720

References Munson, B., & Okiishi, T. (2013). Fundamentals of fluid mechanics (7th

ed.). Hoboken, NJ: John Wiley & Sons.

Figure 1: No Curve

For further information Alejandro Cota – Mechanical Engineering ‘15

Setareh Ganji – Mechanical Engineering ‘15

Mohamad Mirzaei – Mechanical Engineering ‘15

HeeYeon Kwon – Mechanical Engineering ‘16

OPTIMIZING FRISBEE FLUID DYNAMICS VIA NON-DIMENSIONAL DYNAMIC SIMILITUDE TESTING

Background To apply Buckingham Pi Theorem and perform the dimensional analysis we must first decide on the factors, or variables, that we expect will have an effect on the performance of the Frisbee. We foresee the list to include :

Difficulties Encountered

Difficulties: - Shaft vibrations - Frisbee wobbling - Time

Figure 2: 0.2"

Please visit:

http://teammash.edublogs.org/

Solutions: - Trimmed shaft, and increased stability by implementing more points of contact - Increased size of center clearance hole to avoid threads and mechanical binding - Concentrated on one parameter (vary curvature), and adjusted to proper number of data points to save time

Figure 3: 0.5"

Figure 4: 0.75"

Figure 5: 1"

Figure 6: 1.25"

μair : Fluid Dynamic Viscosity

ω : Frisbee Angular Velocity

α : Angle of Attack

ρair : Fluid Density

Vair : Wind Speed

d : Frisbee diameter

F : Force (Lift/Drag)

221hV