210 likes | 383 Views
Group 19 Hing Lawrence Lau Jonathan Lawson Bryan Urquhart Sammy Zargaran. Dr. Eric Lauga. Ph.D. in Applied Mathematics from Harvard in 2005 Assistant professor at MIT in the Mathematics department from 2006 to 2007
E N D
Group 19 Hing Lawrence Lau Jonathan Lawson Bryan Urquhart Sammy Zargaran
Dr. Eric Lauga • Ph.D. in Applied Mathematics from Harvard in 2005 • Assistant professor at MIT in the Mathematics department from 2006 to 2007 • Professor Lauga's research focuses on physical hydrodynamics, micro-fluidics, biophysics and the biomechanics of locomotion • Sammy
Project Objectives • Many microorganisms move by means of flagella. The motion of the flagella propagates down the length like a sine wave. • Sammy
Project Objectives • Similarity analysis can be performed to quantify flow characteristics: • - • This type of creeping flow with Re<<1 is called Stokes Flow • Sammy
Project Objectives • Microorganisms live in the Stokes Flow regime • Viscosity effects dominate over momentum effects • Microorganisms move by means of flagella • These flagella have many degrees of freedom • Why isn’t there a microorganism that moves via single degree of freedom motion? • Sammy
Project Description • Single Degree of Freedom • Capable of motion in Stokes flow (Re << 1) • Never witnessed in nature • A Self-contained torus, designed to move in Stokes Flow, has never been constructed • Project goal was to create a torus that can move in the Stokes Flow regime • How does it work? • Sammy
How it Moves I • The surface of the torus rotates as shown which results in Torus motion. u ω ω u • Jonathan
How it Moves II Flow Field • Jonathan
Final Design: Overview • Features: • Two miniature geared motors to rotate surface • Controlled with model aircraft motor driver for wireless control • Jonathan
Actuation System Motor Mount Dive Disk attached to Motor Assembly Motor • Lawrence
Power System Battery Housing Battery Protection Circuit and Motor Drive Housing Cool Feature: snap fitting base for housings PCB • Lawrence
Control System Motor Driver Motor Driver Housing Receiver Housing Transmitter • Lawrence
Rotating Skin Helical Coil as support to maintain longitudinal cross-section • Lawrence
Heat Generation • Assumptions: • The skin of the torus was a perfect insulator and that no heat would be lost to the fluid • All energy consumed by components was converted into thermal energy The total increase in temperature when the system is run for 30 minutes is 35 K • Jonathan
Power Consumption Theoretical Power Consumption (not loaded): Theoretical battery life is92 mins Actual Power Consumption (loaded) is3.7W while the tested battery life is52 mins • Jonathan
A1 A2 ω a Fluid Simulation I • To gain some initial insight to the torus motion, a MATLAB simulation was constructed. • Approximating a section as a cylinder, shear stresses were calculated. • Integrating the shear stress with respect to area leaves a net force on the torus which is the basis of its motion. • Bryan
Fluid Simulation II • Some results using current size parameters: • Velocity: • This may seem slow, but this is actually faster than the motion expected by our sponsor • Bryan
Performance • The donut successfully rotates as intended around the internal components • Performance Characteristics: • Runtime – 52 minutes • Rotational Speed – 6 rpm • Bryan
Conclusions / Recommendations • Different Motor Controller • Computer control • Actuation • Data Acquisition • Fluid-Torus Interface • Power • Battery Charging • External Power Button • Slip Ring(s) • Bryan
Acknowledgments Tom Chalfant Dr. Nate Delson • Dr. Nathan Delson – Instructor, Mechanical Engineer • Dr. Eric Lauga – Project Sponsor, Mathematician • Chris Cassidy – Design Studio Manager, Development Engineer • AnneTatlock – Faculty Assistant • TomChalfant – Machine Shop Manager, Development Engineer • SteveRoberts – Electronics Lab Manager, Development Engineer • DamonLemmon – Teaching Assistant, UCSD Graduate Student • ShawnThomson – Application Engineer, MicroMo Electronics • Dave Lischer – Project Design Lab Manager, Development Engineer Dr. Eric Lauga Chris Cassidy Bryan Dave Lischer • Bryan