iMarine Impact Laboratory:Creating a new laboratory to analyze water surface impact via the World Wide Web. Tadd Truscott MIT Ocean Engineering January 24, 2004 An apparatus for water surface impact experimentation developed as part of the iMarine WebLab project.
Introduction Design Construction & Implementation System Integration Experimentation Laverty 04’
Outline • Motivation • Project overview • Project Design • System Integration and Control • Project Applications • Experimentation • The next step
Motivation • Numerical Method Validation - Experiments validate theories and numerical techniques. They also promote scientific discovery. Help break down or diversify the problem. • Education - web-based teaching tools. • Naval Architecture - modern approaches to naval architecture problems; educating the next generation of naval architects. • Synergy - integrating classroom learning with numerical simulations and experimentation for a more comprehensive understanding of fluid dynamics.
Scientific Method Observation and description of phenomenon. Formulation of a hypothesis to explain phenomenon (i.e. Mathematical model). Prediction based on Hypothesis. Performance of an experiment to test prediction and hypothesis. Educational Method Lecture or reading to learn principle. Application of principle to students interests (i.e. Homework or research). Prediction based on principle in research or homework. Performance of an experiment to test understanding (real world observation and experimentation solidifies understanding best). Critical thought process: deriving empirical conclusions and reiterating on the process to further scientific knowledge.
Combining resources • Online laboratory concepts help combine resources • Create libraries of articles and literature. • Collection of modern numerical simulations and models. • “WebLabs” allow users to remotely and safely run experiments, computational simulations, and process data on-line. • Collection of experiments can be “harvested” for trends etc. • Help create networks of common research, and researchers. • Stimulate students interests. • Three types of online laboratories • Batch - student sets parameters, and collects data (i.e. weblab.mit.edu). • Sensor - data collection only (i.e. flagploe.mit.edu, Rutgers www.coolclassroom.com). • Interactive - students set parameters at intervals during sensor data collection (i.e. heatex.mit.edu) • “The concept of Internet accessible labs encourages cross-institution cooperation. One can easily imagine students at one university using a laboratory made accessible by a second university. Schools or universities may decide to share the cost of an expensive laboratory and physically establish it at a convenient location. One can also imagine government participation that would offer limited access to national laboratories or facilities like the International Space Station. In time, as online labs proliferate, we may require a discovery process by which a faculty member (or a student) can locate an online lab that offers a particular experiment or technology.” iCampus Project
I-Marine Main • I-Simulate • LAMP • M5D • SWAN • Wigley Hull • Potential flow • Added Mass • Munk Moment • Waves • I-Learn • Lectures • Museum • Photo Archives • Literature resources • Links • I-Experiment • Impact • Wave maker • Spray
I-Experiment • Impact lab: • Free surface interface interaction • Ship Slamming • Mine Dropping • Hydrodynamics • Splash formation • Viscous effects • Three dimensional effects • Air entrainment • Instabilities make it interesting (i.e. surface tension, ball size, imperfections etc). • Variable speeds. • Repeatability
Impact Lab Overview Objects in loader Counter-rotating shooter wheels Sensors & instrumentation Vi Video acquisition h2o Techet 04’
Tank Design • Tank • Acrylic - similar index of refraction to water. • Adjustable window 16” to 20” • Dimensions • Depth 6 ft • Length 6 ft • Width 3ft • ~800 Gallons full • Weight • Full Tank and frame ~6500 lbs
Shooting/Firing Mechanism Design • Shooter • Based on a pitching wheel. • Adjustable golf balls to basketballs. • Specifications • Wheels 16 in • Frame 60 in X 18 in • Wheels 0-1700 rpm • ~35 mph for baseball • Rotate frame <15º • Linear position • Firing • Acrylic container (7 balls) • Holds 7 balls • 1.5 in - 2.25 in • Solenoid actuator • Firing sequence • Billiard balls Pacesettergroup.com
Instrument Design • Instrumentation • Camera: X-Stream VISION XS-3 • Resolution: 1280X1024 1.3 Mpix • Pixel size 12X12 micron • Plug and Play real time • Trigerable • 628 - 32000 fps (resolution based) • 4 GB memory ~10 seconds @ 600 Hz • C-mount • USB 2 • Wave Probes • Analog voltage sensors • RPM and Break Beams • ROS-W (remote optical sensor) • Mounting IDT X-Stream VISION XS-3 Laverty 04’
System Integration and control • Hardware • Motors • 2 Bodine EC Inverted AC 177-3500 RPM • 2 Superior Electric Slo-Syn KML series 200 steps/rev Stepper motors • 1 Linear motion screw drive Nook EZM 3010 • Worm Drive Grove Gear OE Series 134-3 • Motor Controllers • Pacesetter computer analog adjustable speed drive. • National Instruments DAQ - Voltage & Frequency I/O • National Instruments UMI 7764 - Digital In / Analog Out • Grayhill Relay Board - Analog Voltage I/O
System Control • Automation • Synchronization • System Processing • Flow Chart
http://imarine.mit.edu System Flow chart • User Inputs • RPM • Angle • Camera Options Impact Lab CPU Server LabView High Speed Video UMI 7764 DAQ RPM & Break Beams Worm Gear Solenoid Control Wheel Motors Linear Screw Drive Wave Probes Shooting Mechanism Postion
Video Overview • Filmed at 100 fps • Shot at 1000 RPM • 28 mm lens @ 3 m
Applications • Research • Numerical Problems • Use experiments to validate numerical models and vice versa. • There are challenges with high speed/highly 3D hydro problems using numerical simulations so experiments can help • Experiments aren’t always the answer. • Teaching • Ocean engineering • Ship Slamming • Military • Shallow angle of incidence • Spinning projectiles
Curveball History • Robins, Benjamin 1742. New Principles of Gunnery. • Magnus, Gustav 1853. Magnus Effect. Berlin Academy of Sciences award. • Arthur “Candy” Cummings 1867. First pitcher in baseball to pitch a curveball. • Strutt, John W. ‘Lord Rayleigh’ 1877. On the irregular flight of a tennis ball. • Maccoll, J. W. 1928. Aerodynamics of a spinning sphere. Journal of the Royal Aeronautical Society. • Barkla, H. M., Auchterlonie, L. J. 1971. The Magnus or Robbins effect on Rotating spheres. JFM • Brown, F. N. M. 1971. See the wind blow. • Mehta, Rabindra D. 1985. Aerodynamics of Sports Balls. Ann. Rev. Fluid Mech. • Watts, R.G., Ferrer, R. 1987. The lateral force on a spinning sphere: Aerodynamics of a curveball. American Journal of Physics.
Hydrodynamics of Curveballs Free Body Diagram • http://wings.avkids.com/Book/Sports/instructor/curveball-01.html
Video of curveball • 600 fps • 50 mm lans @ 1 m • 1700 RPM release • ~2200 RPM spin • 0º entry angle • #15 Billiard ball
Video of curveball up close • 600 fps • 50 mm lans @ 1 m • 1700 RPM release • ~2200 RPM spin • 0º entry angle • #15 Billiard ball
Next Step • Data • Cl vs omega • Cd vs omega • Continue research into high reynolds # • 3-d PIV
General Impact • History - prior research on surface impact… have this for a backup slide