introduction to aae520 forebody ldv lab
play

Introduction to AAE520 Forebody/LDV Lab Learn to use a water tunnel - PowerPoint PPT Presentation

Feb 20, 2023 •702 likes •952 views

Introduction to AAE520 Forebody/LDV Lab Learn to use a water tunnel Learn about the laser doppler velocimeter (LDV), use it for some measurements Learn about flow visualization Learn about subsonic forebodies at high angle of

  1. Introduction to AAE520 Forebody/LDV Lab •Learn to use a water tunnel •Learn about the laser doppler velocimeter (LDV), use it for some measurements •Learn about flow visualization •Learn about subsonic forebodies at high angle of attack AAE520 S.P. Schneider 14-Jan-08

  2. Introduction to Water Tunnels •Air and water are both Newtonian fluids. Water sometimes used to simulate air. Hydrodynamics is also important for ships, torpedos, etc. •Flow visualization is easy in water tunnels •LDV is easy in water tunnels – particles are ubiquitous •Water leaks cause a lot more trouble than air leaks •Water often hastens corrosion •Surface waves can cause problems AAE520 S.P. Schneider 14-Jan-08

  3. Introduction to ASL Water Tunnel •Obtained surplus from Boeing ca. summer 2002 •Installed, wired, plumbed, fixed in 2002-2003. Motor and controller replaced in 2005-2006. Traverse improved in 2006. •AAE520 Spring 2004 was first real use •Goes up to 1 foot/second, fairly slow •15x20-inch test section is good sized •Nice dye system. Tunnel built for flow viz. •Presently not covering test section, will get surface waves AAE520 S.P. Schneider 14-Jan-08

  4. Water Tunnel Operations •Read the manual summary •If turn off, wait til motor stops before restart •Potentiometer on operations panel controls speed •Flowmeter supposedly calibrated to show test section speed •Don’t go above 12 inch/sec, pump will cavitate and may be damaged if left that way for long •Leave filter off (and unpressurized) to retain particles for LDV. AAE520 S.P. Schneider 14-Jan-08

  5. Water Tunnel Operations, 2 •We may need to clear air from the honeycomb (see p. 18 of manual) •Dye colors the water. Bleach (not too much) reduces color, also controls algae growth. Limit dye usage, may need to replace water anyway •Draining takes about 25 mins. Filling takes about 1/2 hour when no one else is using the water. (New automated fill line and new drain line). • Keep water away from electrical/electronic apparatus! Don’t rely on the GFI! AAE520 S.P. Schneider 14-Jan-08

  6. Water Tunnel/Cone Operations, 3 •Don’t get the water too blue, doing flow viz! There’s no time in the schedule for changing the water, which takes about an hour during which someone must be around. Dilute dye! About 1 part dye: 10 parts water. Plan for a drain-&-fill between groups – start drain when finished. •Look at vortices with dye. Can vary: 1) tunnel speed, 2) cone AOA, 3) cone roll angle, 4) cone height in tunnel, 5) axial location of cone support (is this worth it?) 6) spanwise location of cone (does this matter?), 7) dye injection parameters (dye density, pressure, flow rates). Take photos. AAE520 S.P. Schneider 14-Jan-08

  7. Water Tunnel/Cone Operations, 4 •Always use 2 people to adjust the cone, one to hold the cone and the other to tighten the screws, one on each side of the tunnel. A safety precaution so the cone doesn’t slip while you tighten. •Measure cone angles with inclinometer. •Watch out for the LDV rig when you move the cone. AAE520 S.P. Schneider 14-Jan-08

  8. Water Tunnel/Cone Operations, 5 •Can release the air bubbles from dye reservoir inside cone by removing tube from the back of the cone while cone is in the water. •Please tilt the cone out of the water at the end of the day to let it dry. This minimizes corrosion in the aluminum. Aluminum will corrode if in constant contact with water. AAE520 S.P. Schneider 14-Jan-08

  9. Laser Doppler Velocimeter •See notes on website, followup lecture, section by Ron Adrian in Fluid Mechanics Measurements •Most common optical technique for measuring velocity. Several vendors sell off-the-shelf systems •Nonintrusive operations. Requires particles •Forward scattering operation, as here, enables use of lower cost ($2K) and relatively safe laser • Keep the laser beam out of your eyes! And those of others! AAE520 S.P. Schneider 14-Jan-08

  10. Laser Doppler Velocimeter, 2 •Our first real experience with LDV •Sullivan built a laser and an LDV for his Ph.D. thesis •Present setup adapted from 333L demo. by Collicott •No automated doppler processor, sample photodiode signal with digital scope and process doppler bursts in your own software or with FFT averaging AAE520 S.P. Schneider 14-Jan-08

  11. Sketch of LDV Apparatus Used in 520 & 333L Developed by Prof. Collicott. For 520, split transmitting and receiving optics, place water tunnel test section in between, in place of item 12. Lens 1 For 520, drop mirrors 1 and 2 AAE520 S.P. Schneider 14-Jan-08

  12. Magnified Image of LDV Probe Volume Note Interference Fringes Particles traverse fringes in flow, scatter light at a frequency proportional to their axial speed. First-surface mirror placed before test section, deflect beam into DISA microscope objective at beam intersection, project on cardboard card. 8 Feb. 2006 SPS. AAE520 S.P. Schneider 14-Jan-08

  13. Sample Output from LDV at 4.5 in./sec LDV output reading from scope at 4.5 inches/sec. in water tunnel, 20 Feb. 2004 Fairly typical to good particle doppler shift. Upper signal from photodiode direct, lower signal is high- pass filtered at about 4 kHz to show doppler burst better. AAE520 S.P. Schneider 14-Jan-08

  14. Sample Output from LDV at 9 in/sec. LDV output reading from scope at 9.0 inches/sec. in water tunnel, 20 Feb. 2004 Upper signal from photodiode direct, lower signal is high- pass filtered at about 4 kHz to show doppler burst better. Double the frequency at 4.5 in/sec (note scale!) AAE520 S.P. Schneider 14-Jan-08

  15. More on Laser Doppler Velocimeter •Most groups have been able to get data, although sometimes the doppler bursts are not great •Alignment is tricky (and we are still learning about how to do it). LDV drifts in and out of alignment from day to day. Sullivan says it will drift as you traverse and image through different parts of the window •Some groups had little or nothing, first week in 2004. •Save multiple particle-doppler velocity data at a given location. What is the probability distribution (histogram)? The rms and mean? Look at the statistics. Look at the effects of processing methods. AAE520 S.P. Schneider 14-Jan-08

  16. More on Laser Doppler Velocimeter •For week 2, we will be a little more aggressive in using the LDV. •Suggest you move the traverse to put the probe volume at various locations in the wake, try to do a wake profile. •As of 2006, the traverse can move the LDV probe volume through most of the water tunnel test section. •You can move the LDV table and probe volume in 3D, using the hand cranks. Don’t move the heavy cart itself. •Be careful moving the table around, don’t ram the optics into anything. •Don’t move too much in week 1. If optics go out of alignment, move back. AAE520 S.P. Schneider 14-Jan-08

  17. Aligning the Laser Doppler Velocimeter •Source optics must be carefully aligned to keep beams coplanar and put the intersection and focus where you want the probe volume. Beams must be collimated before first lens •Beams then intersect again and focus on the pinhole. Pinhole must be exactly at the focus, so both beams go through it. Then when the iris blocks the main beams, the pinhole is at the focus of the light scattered from the beam intersection. •Need to see not only blips with light scattered from particles, but blips with wiggles showing doppler-shift light scattered from particles. Blips w/o wiggles are from particles that aren’t in the probe volume AAE520 S.P. Schneider 14-Jan-08

  18. Studying the Laser Doppler Velocimeter •Receiving optics covered to block 633 nm from the lights •Transmitting optics are tricky to align •So probably should not have students adjusting either right now. What can you do? •Look at the signals •Measure the included angle of the beam, for computing the particle speed from the doppler frequency. •Block one beam at a time, look at the result AAE520 S.P. Schneider 14-Jan-08

  19. Laser Doppler Velocimeter, 3 •Leave the laser on all day, turn it off at the end of the day. But turn the lever that blocks the beam, when you aren’t using it, to improve safety. •LDV is set up as an instrument to study and make a few measurements, not as a production instrument. Look at the doppler bursts (not always easy to get, the alignment is very sensitive, ask for help if you get nothing), see how the instrument works, get particle velocities from the doppler bursts you can save. •Leave the water filter off! We need some big particles to scatter light for the LDV. AAE520 S.P. Schneider 14-Jan-08

  20. Flow Visualization •Dye bled from cone into water •Streaklines, streamlines, pathlines •Can vary the flow rate of dye and the air pressure pushing the dye •Too much dye will disturb the flow, color the tunnel water too rapidly •Look for wake vortices, detachment positions, etc. See Bridges paper for some discussion AAE520 S.P. Schneider 14-Jan-08

  21. Forebodies at Angle of Attack •Subsonic forebodies at AOA shed vortices, like cylinder in crossflow. Vortices may remain attached at LE if AOA not too high •Vortices cause asymmetric lift. Vortex lift critical to high AOA maneuvers. Asymmetric vortices can cause side forces that can be hard to control •Nose vortices impinging on F-18 vertical stabilizer causes structural problems •An important issue for high AOA aerodynamics AAE520 S.P. Schneider 14-Jan-08

Recommend

INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION

INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION

TRAINING COURSE ON SOCIAL PROTECTION & FORMALIZATION TRINIDAD AND TOBAGO MARCH 15, 2017 INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION Design of the NIS Assistance from the

547 views • 23 slides
INTRODUCTION Introduction 2/42 INTRODUCTION Alternations I am giving bread to the

INTRODUCTION Introduction 2/42 INTRODUCTION Alternations I am giving bread to the

Patterns of variation in the expression of case and agreement Andrs Brny Leiden University Centre for Linguistics 9 November 2019, BaSIS Workshop a.barany@hum.leidenuniv.nl INTRODUCTION Introduction 2/42 INTRODUCTION

1.37k views • 42 slides
Introduction Introduction Introduction Introduction Outline Motivation Failures

Introduction Introduction Introduction Introduction Outline Motivation Failures

Introduction Introduction Introduction Introduction Outline Motivation Failures Definition and concepts Process and product properties Principles SE Approaches Motivation Software and the economy The economies of

1.03k views • 49 slides
Introduction Introduction Introduction Nationwide Cause for Concern 1

Introduction Introduction Introduction Nationwide Cause for Concern 1

Introduction Introduction Introduction Nationwide Cause for Concern 1 https://www.cdc.gov/std/stats17/infographic.htm Introduction Epidemiology in Western Colorado CPHE Surveillance Data Report, May 2018 Chlamydia Epidemiology in Western

977 views • 39 slides
DAQ introduction Purpose of this talk : (1) Introduction for those who have not been in every

DAQ introduction Purpose of this talk : (1) Introduction for those who have not been in every

DAQ introduction Purpose of this talk : (1) Introduction for those who have not been in every meeting (2) Some ideas of diagrams for section 7.1 (Introduction) of TP. Giles Barr 25 Jan 2018, Pembroke College On DUNE, the reality is there is a

474 views • 10 slides
INTRODUCTION cf. Schneider, Chapter 1 INTRODUCTION THEY ARE OUT TO GET YOU INTRODUCTION WHAT

INTRODUCTION cf. Schneider, Chapter 1 INTRODUCTION THEY ARE OUT TO GET YOU INTRODUCTION WHAT

ADVANCED COMPUTER SECURITY INTRODUCTION cf. Schneider, Chapter 1 INTRODUCTION THEY ARE OUT TO GET YOU INTRODUCTION WHAT IS SECURITY? A systems security policies describe What the system is supposed to do Store and provide access

479 views • 16 slides
Overview Introduction to SMIL Introduction to W3C and XML Introduction to SMIL

Overview Introduction to SMIL Introduction to W3C and XML Introduction to SMIL

Overview Introduction to SMIL Introduction to W3C and XML Introduction to SMIL Writing a SMIL file Adding Media Objects Martin Halvey Clipping media files January 2008 Timing and Synchronising Layout World Wide

387 views • 14 slides
14 Introduction Introduction Bad guys can put malware into Example: hosts

14 Introduction Introduction Bad guys can put malware into Example: hosts

Introduction Introduction source Encapsulation ISO/OSI reference model message M application segment H t H t M transport network datagram H n H n H t M presentation: allow applications to frame link H l H n H t M interpret

583 views • 4 slides
Previous Lecture Introduction to SMIL 2 Introduction to W3C and XML Introduction to SMIL

Previous Lecture Introduction to SMIL 2 Introduction to W3C and XML Introduction to SMIL

Previous Lecture Introduction to SMIL 2 Introduction to W3C and XML Introduction to SMIL Writing a SMIL file Adding Media Objects Martin Halvey Clipping media files January 2008 Timing and Synchronising Layout

322 views • 8 slides
Lecture 1 Andreas Habegger Introduction Zynq Introduction Zynq Introduction Zynq PS vs. PL

Lecture 1 Andreas Habegger Introduction Zynq Introduction Zynq Introduction Zynq PS vs. PL

Introduction Zynq Lecture 1 Andreas Habegger Introduction Zynq Introduction Zynq Introduction Zynq PS vs. PL Processing System Processor Peripherals Data Buses AXI Bus Conclusion BTE5380 - Embedded Systems Octobre 2014 Andreas Habegger

1.81k views • 30 slides
2018.06 01 SMILE5 Introduction S E 5 02 Alpha Cloud M I L 03 Company Introduction 04

2018.06 01 SMILE5 Introduction S E 5 02 Alpha Cloud M I L 03 Company Introduction 04

2018.06 01 SMILE5 Introduction S E 5 02 Alpha Cloud M I L 03 Company Introduction 04 Project References S E 5 PART.1 SMILE5 Introduction M I L Introduction STORION-SMILE5 Residential Energy Storage System Inverter 5kW Output Input

1.06k views • 25 slides
Introduction to CICS Course introduction Course introduction What is CICS? What is an

Introduction to CICS Course introduction Course introduction What is CICS? What is an

Introduction to CICS Course introduction Course introduction What is CICS? What is an application server? Why use an application server? Course introduction Services provided by CICS How CICS applications are defined Scaling CICS to meet

1.84k views • 146 slides
Network Visualization Introduction Presented by Shahed Introduction Introduction Basic

Network Visualization Introduction Presented by Shahed Introduction Introduction Basic

Network Visualization Introduction Presented by Shahed Introduction Introduction Basic building blocks Node Links (relationship between nodes) Spatial information Network data

584 views • 9 slides
Introduction Introduction (1) Main argument of the paper: universities are not only

Introduction Introduction (1) Main argument of the paper: universities are not only

Le jugement des pairs comme outil de management des universits Peer-review as a management tool Christine Musselin (CSO, Sciences Po et CNRS) Avril 2013, Lirrsistible ascension du capitalisme acadmique Introduction Introduction (1)

590 views • 28 slides
JABLOTRON JA-100 introduction November 2011 Introduction Todays goals First introduction of

JABLOTRON JA-100 introduction November 2011 Introduction Todays goals First introduction of

JABLOTRON JA-100 introduction November 2011 Introduction Todays goals First introduction of the brand new JA-100 alarm system Visions Basic architecture System components Setting Help us with final validations You are the FIRST ones

1.69k views • 111 slides
Introduction Introduction to storage and to storage and filesystems filesystems Introduction

Introduction Introduction to storage and to storage and filesystems filesystems Introduction

Moreno Baricevic Gilberto Daz Axel Kohlmeyer Stefano Cozzini ULA ICTP CNR-IOM DEMOCRITOS Merida, VENEZUELA Trieste, ITALY Trieste, ITALY Introduction Introduction to storage and to storage and filesystems filesystems Introduction

1.19k views • 51 slides
1 Introduction Introduction Communication System Baseband an adjective that describes

1 Introduction Introduction Communication System Baseband an adjective that describes

Introduction Introduction Physical Layer Mobile network Global ISP Provides the means to transmit bits Basic Concepts of from sender to receiver, Data Transmission Defines the mechanical, electrical, and Home network timing

463 views • 7 slides
Welcome! Todays Agenda: Topic Introduction Course Introduction Team Practical

Welcome! Todays Agenda: Topic Introduction Course Introduction Team Practical

INFOGR Computer Graphics Jacco Bikker - April-July 2015 - Lecture 1: Introduction Welcome! Todays Agenda: Topic Introduction Course Introduction Team Practical Details Assignments Field Study State of

869 views • 62 slides
Introduction (00) RNDr. Martin Madaras, PhD. madaras@skeletex.xyz Introduction Introduction

Introduction (00) RNDr. Martin Madaras, PhD. madaras@skeletex.xyz Introduction Introduction

Virtual and Augmented Reality Introduction (00) RNDr. Martin Madaras, PhD. madaras@skeletex.xyz Introduction Introduction Who am I? What do I do here? 2 About me Short research bio: - 2014 - finished PhD at FMFI UK - 2014 2016 -

1.3k views • 39 slides
PRESENTATION The Introduction What is the Introduction ? The introduction prepares the audience

PRESENTATION The Introduction What is the Introduction ? The introduction prepares the audience

PRESENTATION The Introduction What is the Introduction ? The introduction prepares the audience for your presentation. It tells them what your presentation is about, why it is important, and finally, what to listen for in your speech. Get the

505 views • 3 slides
How to make a presentation with L A T EX? Introduction to L A T EX Introduction to Beamer

How to make a presentation with L A T EX? Introduction to L A T EX Introduction to Beamer

Introduction to Beamer Hafida Benhidour How to make a presentation with L A T EX? Introduction to L A T EX Introduction to Beamer Introduction to Beamer Hafida Benhidour Department of computer science King Saud University November

732 views • 49 slides
Shenzhen Cuilu jewelry Co., Ltd was founded in 1996 and its a large private enterprise

Shenzhen Cuilu jewelry Co., Ltd was founded in 1996 and its a large private enterprise

Introduction Introduction - - Brief Brief Introduction Introduction of of Cuilu Cuilu Group Group Introduction Introduction - - Brief Brief Introduction Introduction of of Cuilu Cuilu Group Group Shenzhen Cuilu jewelry Co., Ltd

147 views • 14 slides
Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org

Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org

V olunteer C ommunications N etwork (V-C-N.org) Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org Academy Course - 2012-02.24-2208 262: Introduction to ICS-214 : V-C-N.org : Slide: 1 V olunteer C

558 views • 18 slides
Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org

Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org

V olunteer C ommunications N etwork (V-C-N.org) Introduction to ICS- -214 214 Introduction to ICS Official Unit / Incident Log - A V-C-N.org Academy Course - 2012-02.24-2208 262: Introduction to ICS-214 : V-C-N.org : Slide: 1 V olunteer C

735 views • 34 slides

More recommend